-#LyX 1.4.3 created this file. For more info see http://www.lyx.org/
+#LyX 1.4.5 created this file. For more info see http://www.lyx.org/
\lyxformat 245
\begin_document
\begin_header
linkcolor=blue] {hyperref}
%
\sloppy
-\tolerance=500
-\emergencystretch=30pt
+\tolerance=500
+\emergencystretch=30pt
%
\date{}
\end_preamble
\begin_body
\begin_layout Standard
-\begin_inset Note Comment
+\begin_inset Note Note
status collapsed
\begin_layout Standard
\begin_layout Standard
Two resp.
- three consecutive dashes simply result in a long resp.
+ three consecutive dashes would otherwise result in a long resp.
extra long dash.
\end_layout
\begin_layout Standard
into seperate sections/chapters/appendices (it is hard to document PIC or
- Z80 in
+ Z80 in
\end_layout
\begin_layout Standard
\begin_layout Date
\size normal
-SDCC 2.6.4
+SDCC 2.7.5
\size footnotesize
\newline
-$Date$
+$Date:: $
\newline
$Revision$
\end_layout
\begin_layout Standard
-\begin_inset Note Comment
+\begin_inset Note Note
status collapsed
\begin_layout Standard
\emph on
S
\emph default
-mall
+mall
\emph on
D
\emph default
-evice
+evice
\emph on
C
\emph default
-
+
\emph on
C
\emph default
-ompiler) is an open source, retargettable, optimizing ANSI-C compiler by
-
+ompiler) is free open source, retargettable, optimizing ANSI-C compiler
+ by
\series bold
Sandeep Dutta
\series default
, an open source retargetable assembler & linker.
SDCC has extensive language extensions suitable for utilizing various microcont
rollers and underlying hardware effectively.
-
+
\newline
\newline
\end_layout
\begin_layout Itemize
-global sub expression elimination,
+global sub expression elimination,
\end_layout
\begin_layout Itemize
loop optimizations (loop invariant, strength reduction of induction variables
- and loop reversing),
+ and loop reversing),
\end_layout
\begin_layout Itemize
-constant folding & propagation,
+constant folding & propagation,
\end_layout
\begin_layout Itemize
-copy propagation,
+copy propagation,
\end_layout
\begin_layout Itemize
-dead code elimination
+dead code elimination
\end_layout
\begin_layout Itemize
-jump tables for
+jump tables for
\emph on
switch
\emph default
\begin_layout Standard
For the back-end SDCC uses a global register allocation scheme which should
be well suited for other 8 bit MCUs.
-
+
\newline
\newline
The peep hole optimizer uses a rule based substitution mechanism which
is MCU independent.
-
+
\newline
\newline
\begin_inset Text
\begin_layout Standard
-1.175494351E-38,
+1.175494351E-38,
\family roman
\series medium
\shape up
\newline
-The compiler also allows
+The compiler also allows
\emph on
inline assembler code
\emph default
-cyclomatic) to report the relative complexity of a function.
These functions can then be further optimized, or hand coded in assembly
if needed.
-
+
\newline
\newline
-SDCC also comes with a companion source level debugger SDCDB, the debugger
- currently uses ucSim a freeware simulator for 8051 and other micro-controllers.<
+SDCC also comes with a companion source level debugger SDCDB.
+ The debugger currently uses ucSim, a free open source simulator for 8051
+ and other micro-controllers.
\newline
\newline
+The latest SDCC version can be downloaded from
-The latest version can be downloaded from
\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/snap.php}
\end_inset
.
\series bold
-
+
\series default
\emph on
Please note: the compiler will probably always be some steps ahead of this
\end_layout
\begin_layout Standard
-All packages used in this compiler system are
+All packages used in this compiler system are
\emph on
open source
\emph default
- and
+ and
\emph on
freeware
\emph default
; source code for all the sub-packages (pre-processor, assemblers, linkers
- etc) is distributed with the package.
- This documentation is maintained using a freeware word processor (LyX).
+ etc.) is distributed with the package.
+ This documentation is maintained using a free open source word processor
+ (LyX).
\newline
-This
- program is free software; you can redistribute it and/or modify it under
- the terms of the GNU General Public License
+This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License
\begin_inset LatexCommand \index{GNU General Public License, GPL}
\end_inset
In other words, you are welcome to use, share and improve this program.
You are forbidden to forbid anyone else to use, share and improve what
you give them.
- Help stamp out software-hoarding!
+ Help stamp out software-hoarding!
\end_layout
\begin_layout Section
\begin_layout Standard
Throughout this manual, we will use the following convention.
- Commands you have to type in are printed in
+ Commands you have to type in are printed in
\family sans
\series bold
"sans serif"
.
\family default
- Code samples are printed in
+ Code samples are printed in
\family typewriter
typewriter font.
\family default
- Interesting items and new terms are printed in
+ Interesting items and new terms are printed in
\emph on
italic.
\end_layout
\end_layout
\begin_layout Standard
-This version has numerous bug fixes compared with the previous version.
- But we also introduced some incompatibilities with older versions.
+Newer versions have usually numerous bug fixes compared with the previous
+ version.
+ But we also sometimes introduce some incompatibilities with older versions.
Not just for the fun of it, but to make the compiler more stable, efficient
and ANSI compliant
\begin_inset LatexCommand \index{ANSI-compliance}
\end_inset
- (see section
+ (see section
\begin_inset LatexCommand \ref{sub:ANSI-Compliance}
\end_inset
for ANSI-Compliance).
-
+
+\begin_inset Note Note
+status collapsed
+
+\begin_layout Standard
+It would be fine to add to each item, in which version was it changed.
+\end_layout
+
+\end_inset
+
+
\newline
\end_layout
\begin_layout Itemize
short is now equivalent to int (16 bits), it used to be equivalent to char
(8 bits) which is not ANSI compliant.
+ To maintain compatibility, old programs may be compiled using the -
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-short-is-8bits commandline option (see
+\begin_inset LatexCommand \vref{lyx:--short-is-8bits}
+
+\end_inset
+
+).
\end_layout
\begin_layout Itemize
\end_inset
-, e.g.:
+, e.g.:
\newline
\family typewriter
\end_layout
\begin_layout Standard
-The SDCC home page at
+The SDCC home page at
\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/}
\end_inset
Web links to other SDCC related sites can also be found here.
This document can be found in the DOC directory of the source package as
a text or HTML file.
- A pdf version of this document is available at
+ A pdf version of this document is available at
\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/doc/sdccman.pdf}
\end_inset
Some of the other tools (simulator and assembler) included with SDCC contain
their own documentation and can be found in the source distribution.
If you want the latest unreleased software, the complete source package
- is available directly from Subversion on https://svn.sourceforge.net/svnroot/sdcc
-/trunk/sdcc.
+ is available directly from Subversion on https://sdcc.svn.sourceforge.net/svnroot/
+sdcc/trunk/sdcc.
\end_layout
\begin_layout Section
\newline
\family default
-If you can think of some more, please see the section
+If you can think of some more, please see the section
\begin_inset LatexCommand \ref{sub:Requesting-Features}
\end_inset
\end_layout
\begin_layout Standard
-For most users it is sufficient to skip to either section
+For most users it is sufficient to skip to either section
\begin_inset LatexCommand \ref{sub:Building-SDCC-on-Linux}
\end_inset
- (Unix) or section
+ (Unix) or section
\begin_inset LatexCommand \ref{sub:Windows-Install}
\end_inset
\labelwidthstring 00.00.0000
\InsetSpace ~
\InsetSpace ~
-sdccconf_h_dir_separator environment variable, either / or
+sdccconf_h_dir_separator environment variable, either / or
\backslash
\backslash
\end_inset
--disable-pic-port Excludes the PIC port
+-disable-pic-port Excludes the PIC14 port
+\end_layout
+
+\begin_layout List
+\labelwidthstring 00.00.0000
+-
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-disable-pic16-port Excludes the PIC16 port
\end_layout
\begin_layout List
\end_inset
--help` and the man/info pages of `configure` for details.
+-help' and the man/info pages of `configure' for details.
\newline
\newline
The names of the
standard libraries STD_LIB, STD_INT_LIB, STD_LONG_LIB, STD_FP_LIB, STD_DS390_LI
B, STD_XA51_LIB and the environment variables SDCC_DIR_NAME, SDCC_INCLUDE_NAME,
- SDCC_LIB_NAME are defined by `configure` too.
+ SDCC_LIB_NAME are defined by `configure' too.
At the moment it's not possible to change the default settings (it was
simply never required).
\newline
\newline
These configure options are compiled into the binaries,
and can only be changed by rerunning 'configure' and recompiling SDCC.
- The configure options are written in
+ The configure options are written in
\emph on
italics
\emph default
\newline
\newline
-The settings for
+The settings for
\begin_inset Quotes sld
\end_inset
\end_layout
\begin_layout Enumerate
-open source,
+open source,
\end_layout
\begin_layout Enumerate
\end_layout
\begin_layout Enumerate
-the binaries can be built by cross compiling on Sourceforge's compile farm.
+the binaries can be built by cross compiling on SDCC Distributed Compile
+ Farm.
\end_layout
\begin_layout Standard
This is needed for full relocatability of a binary package and to complete
search paths (see section search paths below):
\newline
-
+
\end_layout
\begin_layout Standard
\end_layout
\begin_layout LyX-Code
-./configure
+./configure
\backslash
\newline
\begin_inset Quotes srd
\end_inset
-
+
\backslash
-
+
\newline
RANLIB=
\begin_inset Quotes srd
\begin_inset Quotes srd
\end_inset
-
+
\backslash
\newline
\begin_inset Quotes srd
\end_inset
-
+
\backslash
\newline
\begin_inset Quotes srd
\end_inset
-
+
\backslash
\newline
\begin_inset Quotes srd
\end_inset
-
+
\backslash
\newline
\begin_inset Quotes srd
\end_inset
-
+
\backslash
\newline
\begin_inset Quotes srd
\end_inset
-
+
\backslash
\newline
\begin_inset Quotes srd
\end_inset
-
+
\backslash
\newline
\begin_inset Quotes srd
\end_inset
-
+
\backslash
\newline
\end_layout
\begin_layout Standard
-To
+To
\begin_inset Quotes sld
\end_inset
\end_layout
\begin_layout LyX-Code
-./configure -C
+./configure -C
\backslash
\newline
\begin_inset Quotes srd
\end_inset
-
+
\backslash
\newline
\begin_inset Quotes srd
\end_inset
-
+
\backslash
\newline
\begin_inset Quotes srd
\end_inset
-
+
\backslash
-
+
\newline
include_dir_suffix=
\begin_inset Quotes srd
\begin_inset Quotes srd
\end_inset
-
+
\backslash
\newline
\begin_inset Quotes srd
\end_inset
-
+
\backslash
\newline
\begin_inset Quotes srd
\end_inset
-
+
\backslash
\newline
\begin_inset Quotes srd
\end_inset
-
+
\backslash
\newline
\begin_inset Quotes srd
\end_inset
-
+
\end_layout
\begin_layout Standard
\size footnotesize
*compiler, preprocessor, assembler, and linker
\newline
-**the
+**the
\shape italic
model
\shape default
\begin_layout Standard
\noindent
-The install paths can still be changed during `make install` with e.g.:
+The install paths can still be changed during `make install' with e.g.:
\end_layout
\begin_layout LyX-Code
\begin_layout Standard
Some search paths or parts of them are determined by configure variables
- (in
+ (in
\emph on
italics
\emph default
, see section above).
Further search paths are determined by environment variables during runtime.
-
+
\newline
The paths searched when running the compiler are as follows (the first
catch wins):
\end_inset
-
+
\newline
\end_layout
\end_inset
-
+
\newline
\end_layout
\newline
3.
- Library files
+ Library files
\newline
\end_layout
\begin_layout Standard
-With the exception of
+With the exception of
\begin_inset Quotes sld
\end_inset
\begin_inset Quotes srd
\end_inset
- the
+ the
\shape italic
model
\shape default
is auto-appended by the compiler (e.g.
small, large, z80, ds390 etc.).
-
+
\newline
\end_layout
\end_layout
\begin_layout Standard
-\begin_inset Note Comment
+\begin_inset Note Note
status collapsed
\begin_layout Standard
\series medium
Download the source package
\series default
- either from the SDCC Subversion repository or from the nightly snapshots
+ either from the SDCC Subversion repository or from snapshot builds
\series medium
, it will be named something like sdcc
\series default
-.src
+-src
\series medium
-.t
+-yyyymmdd-rrrr.t
\series default
ar.
\series medium
-gz
+bz2
\series default
-
+
\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/snap.php}
\end_inset
\begin_layout Enumerate
\series medium
-Unpack the file using a command like:
+Unpack the file using a command like:
\family sans
\series bold
-"tar -xvzf sdcc.src.tar.gz
+"tar -xvzf sdcc-src-yyyymmdd-rrrr.tar.bz2
+\begin_inset Quotes srd
+\end_inset
+
+
\family default
-\series default
-"
\series medium
, this will create a sub-directory called sdcc with all of the sources.
\end_layout
\begin_layout Enumerate
-Change directory into the main SDCC directory, for example type:
+Change directory into the main SDCC directory, for example type:
\family sans
\series bold
"cd sdcc
\begin_layout Enumerate
\series medium
-Type
+Type
\family sans
\series bold
"./configure
\begin_layout Enumerate
\series medium
-Type
+Type
\family sans
\series bold
"make
\begin_layout Enumerate
\series medium
-Type
+Type
\family sans
\series bold
"make install"
\series default
This copies the binary executables, the include files, the libraries and
the documentation to the install directories.
- Proceed with section
+ Proceed with section
\begin_inset LatexCommand \ref{sec:Testing-the-SDCC}
\end_inset
\end_layout
\begin_layout Subsection
-Building SDCC on OSX 2.x
+Building SDCC on Mac OS X
\end_layout
\begin_layout Standard
\newline
\newline
-On OSX 2.x it was reported, that the default
- gcc (version 3.1 20020420 (prerelease)) fails to compile SDCC.
+On Mac OS X 10.2.x it was reported, that the
+ default gcc (version 3.1 20020420 (prerelease)) fails to compile SDCC.
Fortunately there's also gcc 2.9.x installed, which works fine.
This compiler can be selected by running 'configure' with:
\end_layout
./configure CC=gcc2 CXX=g++2
\end_layout
+\begin_layout Standard
+Universal (ppc and i386) binaries can be produced on Mac OS X 10.4.x with
+ Xcode.
+ Run 'configure' with:
+\end_layout
+
+\begin_layout LyX-Code
+./configure
+\backslash
+
+\end_layout
+
+\begin_layout LyX-Code
+LDFLAGS="-Wl,-syslibroot,/Developer/SDKs/MacOSX10.4u.sdk -arch i386 -arch
+ ppc"
+\backslash
+
+\end_layout
+
+\begin_layout LyX-Code
+CXXFLAGS = "-O2 -isysroot /Developer/SDKs/MacOSX10.4u.sdk -arch i386 -arch
+ ppc"
+\backslash
+
+\end_layout
+
+\begin_layout LyX-Code
+CFLAGS = "-O2 -isysroot /Developer/SDKs/MacOSX10.4u.sdk -arch i386 -arch ppc"
+\end_layout
+
\begin_layout Subsection
Cross compiling SDCC on Linux for Windows
\end_layout
\newline
\newline
-On Cygwin a
+On Cygwin a
\begin_inset Quotes sld
\end_inset
\newline
In order to install
- Cygwin on Windows download setup.exe from
+ Cygwin on Windows download setup.exe from
\begin_inset LatexCommand \url[www.cygwin.com]{http://www.cygwin.com/}
\end_inset
.
- Run it, set the
+ Run it, set the
\begin_inset Quotes sld
\end_inset
\begin_inset Quotes srd
\end_inset
- to
+ to
\begin_inset Quotes sld
\end_inset
\end_layout
\begin_layout Itemize
-gdb ; the gnu debugger, together with the nice GUI
+gdb ; the gnu debugger, together with the nice GUI
\begin_inset Quotes sld
\end_inset
\end_inset
--login -i
+-login -i
\end_layout
\begin_layout Standard
The other good tip is to make sure you have no //c/-styl
e paths anywhere, use /cygdrive/c/ instead.
Using // invokes a network lookup which is very slow.
- If you think
+ If you think
\begin_inset Quotes sld
\end_inset
\series medium
Download the source package
\series default
- either from the SDCC Subversion repository or from the
-\begin_inset LatexCommand \url[nightly snapshots]{http://sdcc.sourceforge.net/snap.php}
+ either from the SDCC Subversion repository or from the
+\begin_inset LatexCommand \url[snapshot builds]{http://sdcc.sourceforge.net/snap.php}
\end_inset
\series medium
, it will be named something like sdcc
\series default
-.src
+-src
\series medium
-.tgz.
+-yyyymmdd-rrrr.tar.bz2.
\series default
SDCC is distributed with all the projects, workspaces, and files you need
bin_vc to sdcc
\backslash
bin before running SDCC.
-
+
\newline
\newline
when opening the sdcc.dsw workspace or any of the *.dsp projects, then you
need to convert the Unix style line endings to DOS style line endings.
- To do so you can use the
+ To do so you can use the
\begin_inset Quotes sld
\end_inset
\newline
In order to build SDCC with MSVC
you need win32 executables of bison.exe, flex.exe, and gawk.exe.
- One good place to get them is
+ One good place to get them is
\begin_inset LatexCommand \url[here]{http://unxutils.sourceforge.net}
\end_inset
\backslash
util
\backslash
-' and add these lines:
+' and add these lines:
\newline
\InsetSpace ~
\InsetSpace ~
\backslash
util
\backslash
-bison.simple
+bison.simple
\newline
\InsetSpace ~
\InsetSpace ~
\family sans
\series bold
find .
-
+
\backslash
-( -name '*.obj' -o -name '*.lib' -o -name '*.rul'
+( -name '*.obj' -o -name '*.lib' -o -name '*.rul'
\backslash
-) -print -exec rm {}
+) -print -exec rm {}
\backslash
;
\family default
\end_layout
\begin_layout Enumerate
-Download the binary zip package from
+Download the binary zip package from
\begin_inset LatexCommand \url{http://sdcc.sf.net/snap.php}
\end_inset
\end_layout
\begin_layout Standard
-Download the setup program
+Download the setup program
\emph on
sdcc-x.y.z-setup.exe
\emph default
- for an official release from
+ for an official release from
\newline
\begin_inset LatexCommand \url{http://sf.net/project/showfiles.php?group_id=599}
\end_inset
- or a setup program for one of the snapshots
+ or a setup program for one of the snapshots
\emph on
sdcc-yyyymmdd-xxxx-setup.exe
\emph default
- from
+ from
\begin_inset LatexCommand \url{http://sdcc.sf.net/snap.php}
\end_inset
\begin_layout Standard
\noindent
-That's it!
+That's it!
\series bold
configure
\series default
will create the directory tree will all the necessary Makefiles in ~/sdcc.build.
It automagically computes the variables srcdir, top_srcdir and top_buildir
for each directory.
- After running
+ After running
\series bold
make
\series default
generated files are not scattered between the source files.
And the best thing is: if you want to change a file you can leave the original
file untouched in the source directory.
- Simply copy it to the build directory, edit it, enter `make clean`, `rm
- Makefile.dep` and `make`.
-
+ Simply copy it to the build directory, edit it, enter `make clean', `rm
+ Makefile.dep' and `make'.
+
\series bold
make
\series default
with all the other stuff.
You will need several tools (LyX, LaTeX, LaTeX2HTML, pdflatex, dvipdf,
dvips and makeindex) to get the job done.
- Another possibility is to change to the doc directory and to type
+ Another possibility is to change to the doc directory and to type
\family sans
\series bold
there.
You're invited to make changes and additions to this manual (sdcc/doc/sdccman.ly
x).
- Using LyX
+ Using LyX
\begin_inset LatexCommand \url{http://www.lyx.org}
\end_inset
as editor is straightforward.
- Prebuilt documentation in html and pdf format is available from
+ Prebuilt documentation in html and pdf format is available from
\begin_inset LatexCommand \url{http://sdcc.sf.net/snap.php}
\end_inset
\end_inset
.
-
+
\newline
You'll find the pdf version
\begin_inset LatexCommand \index{PDF version of this document}
\end_inset
- at
+ at
\begin_inset LatexCommand \url{http://sdcc.sf.net/doc/sdccman.pdf}
\end_inset
.
-
+
\newline
A html version
\begin_inset LatexCommand \index{HTML version of this document}
\end_inset
- should be online at
+ should be online at
\begin_inset LatexCommand \url{http://sdcc.sf.net/doc/sdccman.html/index.html}
\end_inset
.
\newline
This documentation is in some aspects different from a commercial documentation:
-
+
\end_layout
\begin_layout Itemize
There are many references pointing away from this documentation.
Don't let this distract you.
If there f.e.
- was a reference like
+ was a reference like
\begin_inset LatexCommand \url{http://www.opencores.org}
\end_inset
- together with a statement
+ together with a statement
\begin_inset Quotes sld
\end_inset
-some processors which are targetted by SDCC can be implemented in a
+some processors which are targetted by SDCC can be implemented in a
\emph on
f
\emph default
-ield
+ield
\emph on
p
\emph default
-rogrammable
+rogrammable
\emph on
g
\emph default
-ate
+ate
\emph on
a
\emph default
\begin_inset Quotes srd
\end_inset
- or
+ or
\begin_inset LatexCommand \url{http://sf.net/projects/fpgac}
\end_inset
\end_inset
-
+
\begin_inset Quotes sld
\end_inset
\begin_layout Standard
The first thing you should do after installing your SDCC compiler is to
see if it runs.
- Type
+ Type
\family sans
\series bold
"sdcc -
\family default
\series default
at the prompt, and the program should run and output its version like:
-
+
\newline
\family typewriter
Make sure that the sdcc bin directory is in your executable search path
defined by the PATH environment setting (
\series medium
-see
+see
\series default
-section
+section
\begin_inset LatexCommand \ref{sub:Install-Trouble-shooting}
\end_inset
\newline
\series medium
-SDCC
+SDCC
\series default
-is commonly installed as described in section
+is commonly installed as described in section
\begin_inset Quotes sld
\end_inset
\series medium
Make sure the compiler works on a very simple example.
- Type in the following test.c program using your favorite
+ Type in the following test.c program using your favorite
\series default
-ASCII
+ASCII
\series medium
editor:
\end_layout
\begin_layout Standard
\series medium
-Compile this using the following command:
+Compile this using the following command:
\family sans
\series bold
"sdcc -c test.c".
\family default
\series default
-
+
\series medium
If all goes well, the compiler will generate a test.asm and test.rel file.
Congratulations, you've just compiled your first program with SDCC.
\series medium
The next step is to try it with the linker.
- Type in
+ Type in
\family sans
\series bold
"sdcc test.c
a test.ihx output file.
If this step fails
\series default
-
+
\series medium
(no test.ihx, and the linker generates warnings), then the problem is most
- likely that
+ likely that
\series default
SDCC
\series medium
- cannot find the
+ cannot find the
\series default
/
\series medium
usr/local/share/sdcc/lib directory
\series default
-
+
\series medium
-(see
+(see
\series default
-section
+section
\begin_inset LatexCommand \ref{sub:Install-Trouble-shooting}
\end_inset
\newline
\series medium
-The final test is to ensure
+The final test is to ensure
\series default
SDCC
\series medium
- can use the
+ can use the
\series default
standard
\series medium
\begin_layout Standard
\series medium
-Compile this by typing
+Compile this by typing
\family sans
\series bold
"sdcc test.c"
.
This should generate a test.ihx output file, and it should give no warnings
such as not finding the string.h file.
- If it cannot find the string.h file, then the problem is that
+ If it cannot find the string.h file, then the problem is that
\series default
SDCC
\series medium
cannot find the /usr/local/share/sdcc/include directory
\series default
-
+
\series medium
-(see the
+(see the
\series default
-section
+section
\begin_inset LatexCommand \ref{sub:Install-Trouble-shooting}
\end_inset
Install trouble-shooting section for suggestions).
\series default
- Use option
+ Use option
\series bold
-
\begin_inset ERT
\end_layout
\begin_layout Subsection
-What the
+What the
\begin_inset Quotes sld
\end_inset
\end_layout
\begin_layout Standard
-The
+The
\begin_inset Quotes sld
\end_inset
\end_layout
\begin_layout Subsection
-What the
+What the
\begin_inset Quotes sld
\end_inset
\end_layout
\begin_layout Subsection
-What the
+What the
\begin_inset Quotes sld
\end_inset
\begin_layout Standard
This will install the compiler, other executables libraries and include
files into the appropriate directories.
- See sections
+ See sections
\begin_inset LatexCommand \ref{sub:Install-paths}
\end_inset
At the time of this writing, we find the following programs for gcc-builds:
\newline
-
+
\newline
In <installdir>/bin:
\end_layout
\begin_layout Itemize
as-z80
\series bold
-,
+,
\series default
as-gbz80 - The Z80 and GameBoy Z80 assemblers.
\end_layout
\begin_layout Itemize
link-z80
\series bold
-,
+,
\series default
link-gbz80 - The Z80 and GameBoy Z80 linkers.
\end_layout
\end_inset
- preprocessor
+ preprocessor
\begin_inset LatexCommand \url{http://gcc.gnu.org/}
\end_inset
\end_inset
- is a freeware, opensource simulator developed by Daniel Drotos.
+ is a free open source simulator developed by Daniel Drotos.
The simulator is built as part of the build process.
- For more information visit Daniel's web site at:
+ For more information visit Daniel's web site at:
\begin_inset LatexCommand \url{http://mazsola.iit.uni-miskolc.hu/~drdani/embedded/s51}
\end_inset
\end_inset
is the companion source level debugger.
- More about SDCDB in section
+ More about SDCDB in section
\begin_inset LatexCommand \ref{cha:Debugging-with-SDCDB}
\end_inset
\begin_layout Standard
For single source file 8051 projects the process is very simple.
- Compile your programs with the following command
+ Compile your programs with the following command
\family sans
\series bold
"sdcc sourcefile.c".
\end_inset
.
- If you need another format you might want to use
+ If you need another format you might want to use
\family sans
\shape italic
objdump
\end_inset
+
+\begin_inset Note Note
+status collapsed
+
+\begin_layout Standard
+hyperlinks needed
+\end_layout
+
+\end_inset
+
+ - see also section
+\begin_inset LatexCommand \vref{sub:Postprocessing-the-Intel}
+
+\end_inset
+
).
Both formats are documented in the documentation of srecord
\begin_inset LatexCommand \index{srecord (bin, hex, ... tool)}
\end_inset
-)
+)
\end_layout
\begin_layout Itemize
\end_inset
-
+
\begin_inset LatexCommand \label{OMF file}
\end_inset
\emph on
a
\emph default
-bsolute
+bsolute
\emph on
o
\emph default
-bject
+bject
\emph on
m
\emph default
-odule
+odule
\emph on
f
\emph default
-ormat is commonly used by third party tools (debuggers
+ormat is a subformat of the OMF51 format and is commonly used by third party
+ tools (debuggers
\begin_inset LatexCommand \index{Debugger}
\end_inset
-, simulators, emulators)
+, simulators, emulators).
\end_layout
\begin_layout Itemize
\end_inset
--dumpall) (see section
+-dumpall) (see section
\begin_inset LatexCommand \ref{sub:Intermediate-Dump-Options}
\end_inset
\InsetSpace ~
- and section
+ and section
\begin_inset LatexCommand \ref{sub:The-anatomy-of}
\end_inset
\end_inset
file
+\begin_inset LatexCommand \label{sub:Postprocessing-the-Intel}
+
+\end_inset
+
+
\end_layout
\begin_layout Standard
which is generated by SDCC might include lines of varying length and the
addresses within the file are not guaranteed to be strictly ascending.
If your toolchain or a bootloader does not like this you can use the tool
-
+
\family typewriter
packihx
\family default
\end_inset
- which is part of the SDCC distribution:
+ which is part of the SDCC distribution:
\newline
\newline
of various flavours (crc, add, xor) and to perform other manipulations
(convert, split, crop, offset, ...).
-
+
\newline
\newline
unused memory with 0x12 and the overall 16 bit sum of the complete 64 kByte
block is zero.
If the program counter on an mcs51 runs wild the backfill pattern 0x12
- will be interpreted as an
+ will be interpreted as an
\family typewriter
lcall
\family default
- to address
+ to address
\family typewriter
0x1212
\family default
\family default
\series default
-The srecord package is available at
+The srecord package is available at
\begin_inset LatexCommand \url{http://sf.net/projects/srecord}
\end_inset
\size default
The first two files will need to be compiled separately with the commands:
\size footnotesize
-
+
\size default
\newline
\newline
\newline
-Then compile the source file containing the
+Then compile the source file containing the
\emph on
main()
\emph default
\end_inset
- the files together with the following command:
+ the files together with the following command:
\newline
\newline
\newline
\newline
-Alternatively,
+Alternatively,
\emph on
-foomain.c
+foomain.c
\emph default
-can be separately compiled as well:
+can be separately compiled as well:
\family sans
\series bold
\family default
\series default
-The file containing the
+The file containing the
\emph on
main()
\emph default
function
\emph on
-
+
\emph default
\noun on
must
\noun default
- be the
+ be the
\noun on
first
\noun default
\begin_layout Standard
Some reusable routines may be compiled into a library, see the documentation
for the assembler and linkage editor (which are in <installdir>/share/sdcc/doc)
- for how to create a
+ for how to create a
\emph on
.lib
\begin_inset LatexCommand \index{<file>.lib}
Libraries created in this manner can be included in the command line.
Make sure you include the -L <library-path> option to tell the linker where
to look for these files if they are not in the current directory.
- Here is an example, assuming you have the source file
+ Here is an example, assuming you have the source file
\emph on
foomain.c
\emph default
\emph on
foolib.lib
\emph default
- in the directory
+ in the directory
\emph on
mylib
\emph default
\end_inset
files.
- For an example see the standard library file
+ For an example see the standard library file
\emph on
libsdcc.lib
\emph default
\family sans
\series bold
sdcclib libint.lib _mulint.rel
+\family default
+\series default
+
+\newline
+
+\end_layout
+
+\begin_layout Standard
+Or, if you preffer:
+\family sans
+\series bold
+
+\newline
+
+\end_layout
+
+\begin_layout Standard
+
+\family sans
+\series bold
+sdcclib libint.lib _divsint.rel _divuint.rel _modsint.rel _moduint.rel _mulint.rel
+\family default
\series default
\newline
\begin_layout Standard
If the file already exists in the library, it will be replaced.
- To see what modules and symbols are included in the library, options -s
+ If a list of .rel files is available, you can tell sdcclib to add those
+ files to a library.
+ For example, if the file 'myliblist.txt' contains
+\family sans
+\series bold
+
+\newline
+
+\end_layout
+
+\begin_layout Standard
+
+\family sans
+\series bold
+_divsint.rel
+\end_layout
+
+\begin_layout Standard
+
+\family sans
+\series bold
+_divuint.rel
+\end_layout
+
+\begin_layout Standard
+
+\family sans
+\series bold
+_modsint.rel
+\end_layout
+
+\begin_layout Standard
+
+\family sans
+\series bold
+_moduint.rel
+\end_layout
+
+\begin_layout Standard
+
+\family sans
+\series bold
+_mulint.rel
+\family default
+\series default
+
+\newline
+
+\end_layout
+
+\begin_layout Standard
+Use
+\family sans
+\series bold
+
+\newline
+
+\end_layout
+
+\begin_layout Standard
+
+\family sans
+\series bold
+sdcclib -l libint.lib myliblist.txt
+\family default
+\series default
+
+\newline
+
+\end_layout
+
+\begin_layout Standard
+Additionally, you can instruct sdcclib to compiles the files before adding
+ them to the library.
+ This is achieved using the environment variables SDCCLIB_CC and/or SDCCLIB_AS.
+ For example:
+\family sans
+\series bold
+
+\newline
+
+\end_layout
+
+\begin_layout Standard
+
+\family sans
+\series bold
+set SDCCLIB_CC=sdcc -c
+\end_layout
+
+\begin_layout Standard
+
+\family sans
+\series bold
+sdcclib -l libint.lib myliblist.txt
+\family default
+\series default
+
+\newline
+
+\end_layout
+
+\begin_layout Standard
+To see what modules and symbols are included in the library, options -s
and -m are available.
For example:
\newline
\end_inset
+\begin_inset LatexCommand \label{sec:Command-Line-Options}
+
+\end_inset
+
+
\end_layout
\begin_layout Subsection
\end_inset
processor (Not maintained, not complete).
- AVR users should probably have a look at winavr
+ AVR users should probably have a look at winavr
\begin_inset LatexCommand \url{http://sourceforge.net/projects/winavr}
\end_inset
- or
+ or
\begin_inset LatexCommand \url{http://www.avrfreaks.net/index.php?name=PNphpBB2&file=index}
\end_inset
-.
+, which is based on AVR-port of the gcc compiler.
\end_layout
\begin_layout Standard
-\begin_inset Note Comment
+\begin_inset Note Note
status collapsed
\begin_layout Standard
\end_layout
\begin_layout Standard
-\begin_inset Note Comment
+\begin_inset Note Note
status collapsed
\begin_layout Standard
\series default
- The additional location where the pre processor will look for <..h> or
+ The additional location where the preprocessor will look for <..h> or
\begin_inset Quotes eld
\end_inset
\size large
\bar under
-
+
\series default
\size default
\bar default
Like `-M' but the output mentions only the user header files included with
- `#include
+ `#include
\begin_inset Quotes eld
\end_inset
\size large
\bar under
-
+
\series default
\size default
\bar default
\series bold
-pedantic-parse-number
+\begin_inset LatexCommand \index{pedantic}
+
+\end_inset
+
+
\begin_inset LatexCommand \index{-pedantic-parse-number}
\end_inset
\size large
\bar under
-
+
+\begin_inset LatexCommand \label{lyx:-pedantic-parse-number}
+
+\end_inset
+
+
\series default
\size default
\bar default
-Pedentic parse numbers so that situations like 0xfe-LO_B(3) are parsed properly
+Pedantic parse numbers so that situations like 0xfe-LO_B(3) are parsed properly
and the macro LO_B(3) gets expanded.
- See also #pragma pedantic_parse_number in section
+ See also #pragma pedantic_parse_number
+\begin_inset LatexCommand \vpageref{ite:pedantic_parse_number}
+
+\end_inset
+
+ in section
\begin_inset LatexCommand \ref{sec:Pragmas}
\end_inset
-
+
\emph on
-Note: this functionality is not in conformance with standard!
+Note: this functionality is not in conformance with C99 standard!
\end_layout
\begin_layout List
\end_inset
...
- Pass the preprocessorOption to the preprocessor
+ Pass the preprocessorOption to the preprocessor
\family typewriter
sdcpp
\family default
\end_inset
.
- SDCC uses an adapted version of the preprocessor
+ SDCC uses an adapted version of the preprocessor
\emph on
cpp
\emph default
\emph on
gcc
\emph default
-
+
\begin_inset LatexCommand \url{http://gcc.gnu.org/}
\end_inset
4.1.1\InsetSpace ~
CPP\InsetSpace ~
Manual
- at
+ at
\begin_inset LatexCommand \htmlurl{http://www.gnu.org/software/gcc/onlinedocs/}
\end_inset
The provided value should not overlap any other memory areas such as used
register banks or the data segment and with enough space for the current
application.
- The
+ The
\series bold
-
\begin_inset ERT
\end_inset
option (which is now a default setting) will override this setting, so
- you should also specify the
+ you should also specify the
\series bold
-
\begin_inset ERT
\end_inset
addressable internal ram of the 8051.
- This is
+ This is
\emph on
not
\emph default
\bar under
-
+
\series default
\bar default
The linker output (final object code) is in Intel Hex format.
\bar under
-
+
\series default
\bar default
The linker output (final object code) is in Motorola S19 format
\bar under
-
+
\series default
\bar default
The linker output (final object code) is in ELF format
...
Pass the linkOption to the linker.
- If a bootloader is used an option like
+ If a bootloader is used an option like
\begin_inset Quotes sld
\end_inset
\end_inset
would be typical to set the start of the code segment.
- See also #pragma constseg and #pragma codeseg in section
+ See also #pragma constseg and #pragma codeseg in section
\begin_inset LatexCommand \ref{sec:Pragmas}
\end_inset
\series default
\size large
\emph on
-
+
\size default
\emph default
Generate code for Small Model programs, see section Memory Models for more
area (usually the first 256 bytes in the external ram) for allocating variables
and passing parameters.
- See section
+ See section
\begin_inset LatexCommand \ref{sub:External-Stack}
\end_inset
Causes the linker to use old style for allocating memory areas.
\end_layout
-\begin_layout Standard
-\begin_inset VSpace bigskip
-\end_inset
-
-
-\end_layout
-
-\begin_layout Subsection
-DS390 / DS400 Options
-\begin_inset LatexCommand \index{Options DS390}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{DS390}
-
-\end_inset
-
-
-\end_layout
-
\begin_layout List
\labelwidthstring 00.00.0000
\end_inset
--model-flat24
+-acall-ajmp
\series default
+\InsetSpace ~
-\begin_inset LatexCommand \index{DS390!Options!-\/-model-flat24}
-
-\end_inset
-
-
-\size large
-\emph on
-
-\size default
-\emph default
-Generate 24-bit flat mode code.
- This is the one and only that the ds390 code generator supports right now
- and is default when using
-\emph on
--mds390
-\emph default
-.
- See section Memory Models for more details.
-\end_layout
-
-\begin_layout List
-\labelwidthstring 00.00.0000
-
-\series bold
--
-\begin_inset ERT
-status collapsed
-
-\begin_layout Standard
-
-
-\backslash
-/
-\end_layout
-
-\end_inset
-
--protect-sp-update
-\begin_inset LatexCommand \index{DS390!Options!-\/-protect-sp-update}
-
-\end_inset
-
-
-\series default
- disable interrupts during ESP:SP updates.
-\end_layout
-
-\begin_layout List
-\labelwidthstring 00.00.0000
-
-\series bold
--
-\begin_inset ERT
-status collapsed
-
-\begin_layout Standard
-
-
-\backslash
-/
-\end_layout
-
-\end_inset
-
--stack-10bit
-\series default
-
-\begin_inset LatexCommand \index{DS390!Options!-\/-stack-10bit}
-
-\end_inset
-
- Generate code for the 10 bit stack mode of the Dallas DS80C390 part.
- This is the one and only that the ds390 code generator supports right now
- and is default when using
-\emph on
--mds390
-\emph default
-.
- In this mode, the stack is located in the lower 1K of the internal RAM,
- which is mapped to 0x400000.
- Note that the support is incomplete, since it still uses a single byte
- as the stack pointer.
- This means that only the lower 256 bytes of the potential 1K stack space
- will actually be used.
- However, this does allow you to reclaim the precious 256 bytes of low RAM
- for use for the DATA and IDATA segments.
- The compiler will not generate any code to put the processor into 10 bit
- stack mode.
- It is important to ensure that the processor is in this mode before calling
- any re-entrant functions compiled with this option.
- In principle, this should work with the
-\emph on
--
-\begin_inset ERT
-status collapsed
-
-\begin_layout Standard
-
-
-\backslash
-/
-\end_layout
-
-\end_inset
-
--stack-auto
-\begin_inset LatexCommand \index{-\/-stack-auto}
-
-\end_inset
-
-
-\emph default
- option, but that has not been tested.
- It is incompatible with the
-\emph on
--
-\begin_inset ERT
-status collapsed
-
-\begin_layout Standard
-
-
-\backslash
-/
-\end_layout
-
-\end_inset
-
--xstack
-\begin_inset LatexCommand \index{-\/-xstack}
-
-\end_inset
-
-
-\emph default
- option.
- It also only makes sense if the processor is in 24 bit contiguous addressing
- mode (see the
-\emph on
--
-\begin_inset ERT
-status collapsed
-
-\begin_layout Standard
-
-
-\backslash
-/
-\end_layout
-
-\end_inset
-
--model-flat24 option
-\emph default
-).
-\end_layout
-
-\begin_layout List
-\labelwidthstring 00.00.0000
-
-\series bold
--
-\begin_inset ERT
-status collapsed
-
-\begin_layout Standard
-
-
-\backslash
-/
-\end_layout
-
-\end_inset
-
--stack-probe
-\begin_inset LatexCommand \index{DS390!Options!-\/-stack-probe}
-
-\end_inset
-
-
-\series default
- insert call to function __stack_probe at each function prologue.
-\end_layout
-
-\begin_layout List
-\labelwidthstring 00.00.0000
-
-\series bold
--
-\begin_inset ERT
-status collapsed
-
-\begin_layout Standard
-
-
-\backslash
-/
-\end_layout
-
-\end_inset
-
--tini-libid
-\begin_inset LatexCommand \index{DS390!Options!-\/-tini-libid}
-
-\end_inset
-
-
-\series default
- <nnnn> LibraryID used in -mTININative.
-
-\end_layout
-
-\begin_layout List
-\labelwidthstring 00.00.0000
-
-\series bold
--
-\begin_inset ERT
-status collapsed
-
-\begin_layout Standard
-
-
-\backslash
-/
-\end_layout
-
-\end_inset
-
--use-accelerator
-\begin_inset LatexCommand \index{DS390!Options!-\/-use-accelerator}
+\begin_inset LatexCommand \index{-\/-acall-ajmp}
\end_inset
-
-\series default
- generate code for DS390 Arithmetic Accelerator.
-
+ Replaces the three byte instructions lcall/ljmp with the two byte instructions
+ acall/ajmp.
+ Only use this option if your code is in the same 2k block of memory.
+ You may need to use this option for some 8051 derivatives which lack the
+ lcall/ljmp instructions..
\end_layout
\begin_layout Standard
\end_layout
\begin_layout Subsection
-Z80 Options
-\begin_inset LatexCommand \index{Options Z80}
+DS390 / DS400 Options
+\begin_inset LatexCommand \index{Options DS390}
\end_inset
-\begin_inset LatexCommand \index{Z80}
+\begin_inset LatexCommand \index{DS390}
\end_inset
\end_inset
--callee-saves-bc
+-model-flat24
\series default
-\begin_inset LatexCommand \index{Z80!Options!-\/-callee-saves-bc}
+\begin_inset LatexCommand \index{DS390!Options!-\/-model-flat24}
\end_inset
\size large
\emph on
-
+
\size default
\emph default
-Force a called function to always save BC.
+Generate 24-bit flat mode code.
+ This is the one and only that the ds390 code generator supports right now
+ and is default when using
+\emph on
+-mds390
+\emph default
+.
+ See section Memory Models for more details.
\end_layout
\begin_layout List
\end_inset
--no-std-crt0
-\series default
-
-\begin_inset LatexCommand \index{Z80!Options!-\/-no-std-crt0}
-
-\end_inset
-
- When linking, skip the standard crt0.o object file.
- You must provide your own crt0.o for your system when linking.
-
-\end_layout
-
-\begin_layout Standard
-\begin_inset VSpace bigskip
-\end_inset
-
-
-\end_layout
-
-\begin_layout Subsection
-Optimization Options
-\begin_inset LatexCommand \index{Options optimization}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{Optimization options}
+-protect-sp-update
+\begin_inset LatexCommand \index{DS390!Options!-\/-protect-sp-update}
\end_inset
+\series default
+ disable interrupts during ESP:SP updates.
\end_layout
\begin_layout List
\end_inset
--nogcse
-\begin_inset LatexCommand \index{-\/-nogcse}
+-stack-10bit
+\series default
-\end_inset
+\begin_inset LatexCommand \index{DS390!Options!-\/-stack-10bit}
+\end_inset
-\series default
- Will not do global subexpression elimination, this option may be used when
- the compiler creates undesirably large stack/data spaces to store compiler
- temporaries (
+ Generate code for the 10 bit stack mode of the Dallas DS80C390 part.
+ This is the one and only that the ds390 code generator supports right now
+ and is default when using
\emph on
-s
+-mds390
\emph default
-pill
+.
+ In this mode, the stack is located in the lower 1K of the internal RAM,
+ which is mapped to 0x400000.
+ Note that the support is incomplete, since it still uses a single byte
+ as the stack pointer.
+ This means that only the lower 256 bytes of the potential 1K stack space
+ will actually be used.
+ However, this does allow you to reclaim the precious 256 bytes of low RAM
+ for use for the DATA and IDATA segments.
+ The compiler will not generate any code to put the processor into 10 bit
+ stack mode.
+ It is important to ensure that the processor is in this mode before calling
+ any re-entrant functions compiled with this option.
+ In principle, this should work with the
\emph on
-loc
-\emph default
-ations, sloc
-\begin_inset LatexCommand \index{sloc (spill location)}
+-
+\begin_inset ERT
+status collapsed
-\end_inset
+\begin_layout Standard
-).
- A warning message will be generated when this happens and the compiler
- will indicate the number of extra bytes it allocated.
- It is recommended that this option NOT be used, #pragma\InsetSpace ~
-nogcse
-\begin_inset LatexCommand \index{\#pragma nogcse}
+
+\backslash
+/
+\end_layout
\end_inset
- can be used to turn off global subexpression elimination
-\begin_inset LatexCommand \index{Subexpression elimination}
+-stack-auto
+\begin_inset LatexCommand \index{-\/-stack-auto}
\end_inset
- for a given function only.
-\end_layout
-
-\begin_layout List
-\labelwidthstring 00.00.0000
-\series bold
+\emph default
+ option, but that has not been tested.
+ It is incompatible with the
+\emph on
-
\begin_inset ERT
status collapsed
\end_inset
--noinvariant
-\begin_inset LatexCommand \index{-\/-noinvariant}
+-xstack
+\begin_inset LatexCommand \index{-\/-xstack}
\end_inset
-\series default
- Will not do loop invariant optimizations, this may be turned off for reasons
- explained for the previous option.
- For more details of loop optimizations performed see Loop Invariants in
- section
-\begin_inset LatexCommand \ref{sub:Loop-Optimizations}
+\emph default
+ option.
+ It also only makes sense if the processor is in 24 bit contiguous addressing
+ mode (see the
+\emph on
+-
+\begin_inset ERT
+status collapsed
-\end_inset
+\begin_layout Standard
-.
- It is recommended that this option NOT be used, #pragma\InsetSpace ~
-noinvariant
-\begin_inset LatexCommand \index{\#pragma noinvariant}
+
+\backslash
+/
+\end_layout
\end_inset
- can be used to turn off invariant optimizations for a given function only.
-\end_layout
+-model-flat24 option
+\emph default
+).
+\series bold
+
+\begin_inset Note Note
+status collapsed
\begin_layout List
\labelwidthstring 00.00.0000
\series bold
-
\begin_inset ERT
-status collapsed
+status open
\begin_layout Standard
\end_inset
--noinduction
-\begin_inset LatexCommand \index{-\/-noinduction}
+-stack-8-bit - switches off the 10-bit mode
+\end_layout
\end_inset
-\series default
- Will not do loop induction optimizations, see section strength reduction
- for more details.
- It is recommended that this option is NOT used, #pragma\InsetSpace ~
-noinduction
-\begin_inset LatexCommand \index{\#pragma noinduction}
-
-\end_inset
-
- can be used to turn off induction optimizations for a given function only.
\end_layout
\begin_layout List
\end_inset
--nojtbound
-\begin_inset LatexCommand \index{-\/-nojtbound}
+-stack-probe
+\begin_inset LatexCommand \index{DS390!Options!-\/-stack-probe}
\end_inset
-\size large
-\bar under
-
\series default
-\size default
-\bar default
- Will not generate boundary condition check when switch statements
-\begin_inset LatexCommand \index{switch statement}
-
-\end_inset
-
- are implemented using jump-tables.
- See section
-\begin_inset LatexCommand \ref{sub:'switch'-Statements}
-
-\end_inset
-
-\InsetSpace ~
-Switch Statements for more details.
- It is recommended that this option is NOT used, #pragma\InsetSpace ~
-nojtbound
-\begin_inset LatexCommand \index{\#pragma nojtbound}
-
-\end_inset
-
- can be used to turn off boundary checking for jump tables for a given function
- only.
+ insert call to function __stack_probe at each function prologue.
\end_layout
\begin_layout List
\series bold
-
\begin_inset ERT
-status collapsed
+status open
\begin_layout Standard
\end_inset
--noloopreverse
-\begin_inset LatexCommand \index{-\/-noloopreverse}
+-tini-libid
+\begin_inset LatexCommand \index{DS390!Options!-\/-tini-libid}
\end_inset
\series default
-\size large
-
-\size default
-Will not do loop reversal
-\begin_inset LatexCommand \index{Loop reversing}
-
-\end_inset
+ <nnnn> LibraryID used in -mTININative.
-optimization.
\end_layout
\begin_layout List
\labelwidthstring 00.00.0000
+
+\series bold
-
\begin_inset ERT
status collapsed
\end_inset
--
-\series bold
-nolabelopt
-\series default
-
-\begin_inset LatexCommand \index{-\/-nolabelopt }
+-use-accelerator
+\begin_inset LatexCommand \index{DS390!Options!-\/-use-accelerator}
\end_inset
-Will not optimize labels (makes the dumpfiles more readable).
-\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\series default
+ generate code for DS390 Arithmetic Accelerator.
-\series bold
--
-\begin_inset ERT
-status collapsed
+\end_layout
\begin_layout Standard
+\begin_inset VSpace bigskip
+\end_inset
-\backslash
-/
\end_layout
-\end_inset
-
--no-xinit-opt
-\begin_inset LatexCommand \index{-\/-no-xinit-opt}
+\begin_layout Subsection
+Z80 Options
+\begin_inset LatexCommand \index{Options Z80}
\end_inset
-\series default
- Will not memcpy initialized data from code space into xdata space.
- This saves a few bytes in code space if you don't have initialized data
-\begin_inset LatexCommand \index{Variable initialization}
+\begin_inset LatexCommand \index{Z80}
\end_inset
-.
+
\end_layout
\begin_layout List
\end_inset
--nooverlay
-\begin_inset LatexCommand \index{-\/-nooverlay}
+-callee-saves-bc
+\series default
+
+\begin_inset LatexCommand \index{Z80!Options!-\/-callee-saves-bc}
\end_inset
-\series default
- The compiler will not overlay parameters and local variables of any function,
- see section Parameters and local variables for more details.
+\size large
+\emph on
+
+\size default
+\emph default
+Force a called function to always save BC.
\end_layout
\begin_layout List
\end_inset
--no-peep
-\begin_inset LatexCommand \index{-\/-no-peep}
+-no-std-crt0
+\series default
-\end_inset
+\begin_inset LatexCommand \index{Z80!Options!-\/-no-std-crt0}
+\end_inset
-\series default
- Disable peep-hole optimization with built-in rules.
+ When linking, skip the standard crt0.o object file.
+ You must provide your own crt0.o for your system when linking.
\end_layout
\begin_layout List
\end_inset
--peep-file
+-portmode=
\series default
-
-\begin_inset LatexCommand \index{-\/-peep-file}
-
-\end_inset
-
-\InsetSpace ~
-<filename> This option can be used to use additional rules to be used by
- the peep hole optimizer.
- See section
-\begin_inset LatexCommand \ref{sub:Peephole-Optimizer}
+<Value>
+\begin_inset LatexCommand \index{Z80!Options!-\/-portmode=<Value>}
\end_inset
-\InsetSpace ~
-Peep Hole optimizations for details on how to write these rules.
+ Determinate PORT I/O mode (<Value> is z80 or z180).
\end_layout
\begin_layout List
\end_inset
--peep-asm
-\begin_inset LatexCommand \index{-\/-peep-asm}
-
-\end_inset
-
-
+-asm=
\series default
- Pass the inline assembler code through the peep hole optimizer.
- This can cause unexpected changes to inline assembler code, please go through
- the peephole optimizer
-\begin_inset LatexCommand \index{Peephole optimizer}
+<Value>
+\begin_inset LatexCommand \index{Z80!Options!-\/-asm=<Value>}
\end_inset
- rules defined in the source file tree '<target>/peeph.def' before using
- this option.
+ Define assembler name (<Value> is rgbds, asxxxx, isas or z80asm).
\end_layout
\begin_layout List
\end_inset
--opt-code-speed
-\begin_inset LatexCommand \index{-\/-opt-code-speed}
+-codeseg
+\series default
+\InsetSpace ~
+<Value>
+\begin_inset LatexCommand \index{Z80!Options!-\/-codeseg <Value>}
\end_inset
-
-\series default
- The compiler will optimize code generation towards fast code, possibly
- at the expense of code size.
+ Use <Value> for the code segment name.
\end_layout
\begin_layout List
\end_inset
--opt-code-size
-\begin_inset LatexCommand \index{-\/-opt-code-size}
+-constseg
+\series default
+\InsetSpace ~
+<Value>
+\begin_inset LatexCommand \index{Z80!Options!-\/-constseg <Value>}
\end_inset
-
-\series default
- The compiler will optimize code generation towards compact code, possibly
- at the expense of code speed.
+ Use <Value> for the const segment name.
\end_layout
-\begin_layout Standard
+\begin_layout List
+\labelwidthstring 00.00.0000
\begin_inset VSpace bigskip
\end_inset
\end_layout
\begin_layout Subsection
-Other Options
-\begin_inset LatexCommand \index{Options other}
+GBZ80 Options
+\begin_inset LatexCommand \index{Options GBZ80}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{GBZ80}
\end_inset
\labelwidthstring 00.00.0000
\series bold
--c\InsetSpace ~
-
\begin_inset ERT
status collapsed
\end_inset
--compile-only
-\begin_inset LatexCommand \index{-\/-compile-only}
+-callee-saves-bc
+\series default
+
+\begin_inset LatexCommand \index{GBZ80!Options!-\/-callee-saves-bc}
\end_inset
-\begin_inset LatexCommand \index{-c -\/-compile-only}
+\size large
+\emph on
-\end_inset
+\size default
+\emph default
+Force a called function to always save BC.
+\end_layout
+\begin_layout List
+\labelwidthstring 00.00.0000
+\series bold
+-bo
\series default
- will compile and assemble the source, but will not call the linkage editor.
+\InsetSpace ~
+<Num>
+\begin_inset LatexCommand \index{GBZ80!Options!-bo <Num>}
+
+\end_inset
+
+ Use code bank <Num>.
\end_layout
\begin_layout List
\labelwidthstring 00.00.0000
\series bold
--
+-ba
\series default
+\InsetSpace ~
+<Num>
+\begin_inset LatexCommand \index{GBZ80!Options!-ba <Num>}
+
+\end_inset
+
+ Use data bank <Num>.
+\end_layout
+
+\begin_layout List
+\labelwidthstring 00.00.0000
+\series bold
+-
\begin_inset ERT
status collapsed
\end_inset
-
-\series bold
--c1mode
-\begin_inset LatexCommand \index{-\/-c1mode}
+-codeseg
+\series default
+\InsetSpace ~
+<Value>
+\begin_inset LatexCommand \index{GBZ80!Options!-\/-codeseg <Value>}
\end_inset
-
-\series default
- reads the preprocessed source from standard input and compiles it.
- The file name for the assembler output must be specified using the -o option.
+ Use <Value> for the code segment name.
\end_layout
\begin_layout List
\labelwidthstring 00.00.0000
\series bold
--E
-\begin_inset LatexCommand \index{-E}
+-
+\begin_inset ERT
+status collapsed
-\end_inset
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+\end_inset
+-constseg
\series default
- Run only the C preprocessor.
- Preprocess all the C source files specified and output the results to standard
- output.
+\InsetSpace ~
+<Value>
+\begin_inset LatexCommand \index{GBZ80!Options!-\/-constseg <Value>}
+
+\end_inset
+
+ Use <Value> for the const segment name.
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Standard
+\begin_inset VSpace bigskip
+\end_inset
-\series bold
--o\InsetSpace ~
-<path/file>
-\begin_inset LatexCommand \index{-o <path/file>}
+
+\end_layout
+
+\begin_layout Subsection
+Optimization Options
+\begin_inset LatexCommand \index{Options optimization}
\end_inset
-
-\series default
-The output path resp.
- file where everything will be placed.
- If the parameter is a path, it must have a trailing slash (or backslash
- for the Windows binaries) to be recognized as a path.
-
+
+\begin_inset LatexCommand \index{Optimization options}
+
+\end_inset
+
+
\end_layout
\begin_layout List
\end_inset
--stack-auto
-\begin_inset LatexCommand \index{-\/-stack-auto}
+-nogcse
+\begin_inset LatexCommand \index{-\/-nogcse}
\end_inset
\series default
-\size large
+ Will not do global subexpression elimination, this option may be used when
+ the compiler creates undesirably large stack/data spaces to store compiler
+ temporaries (
\emph on
-
-\size default
+s
\emph default
-All functions in the source file will be compiled as
+pill
\emph on
-reentrant
+loc
\emph default
-
-\begin_inset LatexCommand \index{reentrant}
+ations, sloc
+\begin_inset LatexCommand \index{sloc (spill location)}
\end_inset
-, i.e.
- the parameters and local variables will be allocated on the stack
-\begin_inset LatexCommand \index{stack}
+).
+ A warning message will be generated when this happens and the compiler
+ will indicate the number of extra bytes it allocated.
+ It is recommended that this option NOT be used, #pragma\InsetSpace ~
+nogcse
+\begin_inset LatexCommand \index{\#pragma nogcse}
\end_inset
-.
- See section
-\begin_inset LatexCommand \ref{sec:Parameters-and-Local-Variables}
+ can be used to turn off global subexpression elimination
+\begin_inset LatexCommand \index{Subexpression elimination}
\end_inset
- Parameters and Local Variables for more details.
- If this option is used all source files in the project should be compiled
- with this option.
- It automatically implies --int-long-reent and --float-reent.
-
+ for a given function only.
\end_layout
\begin_layout List
\end_inset
--callee-saves
-\begin_inset LatexCommand \index{-\/-callee-saves}
+-noinvariant
+\begin_inset LatexCommand \index{-\/-noinvariant}
\end_inset
- function1[,function2][,function3]....
\series default
- The compiler by default uses a caller saves convention for register saving
- across function calls, however this can cause unnecessary register pushing
- & popping when calling small functions from larger functions.
- This option can be used to switch the register saving convention for the
- function names specified.
- The compiler will not save registers when calling these functions, no extra
- code will be generated at the entry & exit (function prologue
-\series bold
-
-\begin_inset LatexCommand \index{function prologue}
+ Will not do loop invariant optimizations, this may be turned off for reasons
+ explained for the previous option.
+ For more details of loop optimizations performed see Loop Invariants in
+ section
+\begin_inset LatexCommand \ref{sub:Loop-Optimizations}
\end_inset
-
-\series default
- & epilogue
-\series bold
-
-\begin_inset LatexCommand \index{function epilogue}
+.
+ It is recommended that this option NOT be used, #pragma\InsetSpace ~
+noinvariant
+\begin_inset LatexCommand \index{\#pragma noinvariant}
\end_inset
+ can be used to turn off invariant optimizations for a given function only.
+\end_layout
+
+\begin_layout List
+\labelwidthstring 00.00.0000
-\series default
-) for these functions to save & restore the registers used by these functions,
- this can SUBSTANTIALLY reduce code & improve run time performance of the
- generated code.
- In the future the compiler (with inter procedural analysis) will be able
- to determine the appropriate scheme to use for each function call.
- DO NOT use this option for built-in functions such as _mulint..., if this
- option is used for a library function the appropriate library function
- needs to be recompiled with the same option.
- If the project consists of multiple source files then all the source file
- should be compiled with the same -
+\series bold
+-
\begin_inset ERT
status collapsed
\end_inset
--callee-saves option string.
- Also see #pragma\InsetSpace ~
-callee_saves
-\begin_inset LatexCommand \index{\#pragma callee\_saves}
+-noinduction
+\begin_inset LatexCommand \index{-\/-noinduction}
\end_inset
-.
+
+\series default
+ Will not do loop induction optimizations, see section strength reduction
+ for more details.
+ It is recommended that this option is NOT used, #pragma\InsetSpace ~
+noinduction
+\begin_inset LatexCommand \index{\#pragma noinduction}
+
+\end_inset
+
+ can be used to turn off induction optimizations for a given function only.
\end_layout
\begin_layout List
\end_inset
--debug
-\begin_inset LatexCommand \index{-\/-debug}
+-nojtbound
+\begin_inset LatexCommand \index{-\/-nojtbound}
\end_inset
+\size large
\bar under
-
+
\series default
+\size default
\bar default
-When this option is used the compiler will generate debug information.
- The debug information collected in a file with .cdb extension can be used
- with the SDCDB.
- For more information see documentation for SDCDB.
- Another file with no extension contains debug information in AOMF or AOMF51
-\begin_inset LatexCommand \index{AOMF, AOMF51}
+ Will not generate boundary condition check when switch statements
+\begin_inset LatexCommand \index{switch statement}
\end_inset
- format which is commonly used by third party tools.
-\end_layout
+ are implemented using jump-tables.
+ See section
+\begin_inset LatexCommand \ref{sub:'switch'-Statements}
-\begin_layout List
-\labelwidthstring 00.00.0000
+\end_inset
-\series bold
--S
-\begin_inset LatexCommand \index{-S}
+\InsetSpace ~
+Switch Statements for more details.
+ It is recommended that this option is NOT used, #pragma\InsetSpace ~
+nojtbound
+\begin_inset LatexCommand \index{\#pragma nojtbound}
\end_inset
-
-\size large
-\bar under
-
-\series default
-\size default
-\bar default
-Stop after the stage of compilation proper; do not assemble.
- The output is an assembler code file for the input file specified.
+ can be used to turn off boundary checking for jump tables for a given function
+ only.
\end_layout
\begin_layout List
\end_inset
--int-long-reent
-\begin_inset LatexCommand \index{-\/-int-long-reent}
+-noloopreverse
+\begin_inset LatexCommand \index{-\/-noloopreverse}
\end_inset
\series default
- Integer (16 bit) and long (32 bit) libraries have been compiled as reentrant.
- Note by default these libraries are compiled as non-reentrant.
- See section Installation for more details.
+\size large
+
+\size default
+Will not do loop reversal
+\begin_inset LatexCommand \index{Loop reversing}
+
+\end_inset
+
+optimization.
\end_layout
\begin_layout List
\labelwidthstring 00.00.0000
-
-\series bold
-
\begin_inset ERT
status collapsed
\end_inset
--cyclomatic
-\begin_inset LatexCommand \index{-\/-cyclomatic}
-
-\end_inset
-
-
-\bar under
-
+-
+\series bold
+nolabelopt
\series default
-\bar default
-This option will cause the compiler to generate an information message for
- each function in the source file.
- The message contains some
-\emph on
-important
-\emph default
- information about the function.
- The number of edges and nodes the compiler detected in the control flow
- graph of the function, and most importantly the
-\emph on
-cyclomatic complexity
-\begin_inset LatexCommand \index{Cyclomatic complexity}
-\end_inset
+\begin_inset LatexCommand \index{-\/-nolabelopt }
+\end_inset
-\emph default
- see section on Cyclomatic Complexity for more details.
+Will not optimize labels (makes the dumpfiles more readable).
\end_layout
\begin_layout List
\end_inset
--float-reent
-\begin_inset LatexCommand \index{-\/-float-reent}
+-no-xinit-opt
+\begin_inset LatexCommand \index{-\/-no-xinit-opt}
\end_inset
\series default
- Floating point library is compiled as reentrant
-\begin_inset LatexCommand \index{reentrant}
+ Will not memcpy initialized data from code space into xdata space.
+ This saves a few bytes in code space if you don't have initialized data
+\begin_inset LatexCommand \index{Variable initialization}
\end_inset
.
- See section Installation for more details.
\end_layout
\begin_layout List
\end_inset
--main-return
-\begin_inset LatexCommand \index{-\/-main-return}
+-nooverlay
+\begin_inset LatexCommand \index{-\/-nooverlay}
\end_inset
\series default
- This option can be used if the code generated is called by a monitor program
- or if the main routine includes an endless loop.
- This option results in slightly smaller code and saves two bytes of stack
- space.
- The return from the 'main'
-\begin_inset LatexCommand \index{main return}
-
-\end_inset
-
- function will return to the function calling main.
- The default setting is to lock up i.e.
- generate a '
-\family typewriter
-sjmp .
-\family default
-'.
+ The compiler will not overlay parameters and local variables of any function,
+ see section Parameters and local variables for more details.
\end_layout
\begin_layout List
\end_inset
--nostdinc
-\begin_inset LatexCommand \index{-\/-nostdinc}
+-no-peep
+\begin_inset LatexCommand \index{-\/-no-peep}
\end_inset
\series default
- This will prevent the compiler from passing on the default include path
- to the preprocessor.
+ Disable peep-hole optimization with built-in rules.
\end_layout
\begin_layout List
\end_inset
--nostdlib
-\begin_inset LatexCommand \index{-\/-nostdlib}
+-peep-file
+\series default
-\end_inset
+\begin_inset LatexCommand \index{-\/-peep-file}
+\end_inset
-\series default
- This will prevent the compiler from passing on the default library
-\begin_inset LatexCommand \index{Libraries}
+\InsetSpace ~
+<filename> This option can be used to use additional rules to be used by
+ the peep hole optimizer.
+ See section
+\begin_inset LatexCommand \ref{sub:Peephole-Optimizer}
\end_inset
- path to the linker.
+\InsetSpace ~
+Peep Hole optimizations for details on how to write these rules.
\end_layout
\begin_layout List
\end_inset
--verbose
-\begin_inset LatexCommand \index{-\/-verbose}
+-peep-asm
+\begin_inset LatexCommand \index{-\/-peep-asm}
\end_inset
\series default
- Shows the various actions the compiler is performing.
-\end_layout
-
-\begin_layout List
-\labelwidthstring 00.00.0000
-
-\series bold
--V
-\begin_inset LatexCommand \index{-V}
+ Pass the inline assembler code through the peep hole optimizer.
+ This can cause unexpected changes to inline assembler code, please go through
+ the peephole optimizer
+\begin_inset LatexCommand \index{Peephole optimizer}
\end_inset
-
-\series default
- Shows the actual commands the compiler is executing.
+ rules defined in the source file tree '<target>/peeph.def' before using
+ this option.
\end_layout
\begin_layout List
\end_inset
--no-c-code-in-asm
-\begin_inset LatexCommand \index{-\/-no-c-code-in-asm}
+-opt-code-speed
+\begin_inset LatexCommand \index{-\/-opt-code-speed}
\end_inset
\series default
- Hides your ugly and inefficient c-code from the asm file, so you can always
- blame the compiler :)
+ The compiler will optimize code generation towards fast code, possibly
+ at the expense of code size.
\end_layout
\begin_layout List
\end_inset
--no-peep-comments
-\begin_inset LatexCommand \index{-\/-no-peep-comments}
+-opt-code-size
+\begin_inset LatexCommand \index{-\/-opt-code-size}
\end_inset
\series default
- Will not include peep-hole comments in the generated files.
+ The compiler will optimize code generation towards compact code, possibly
+ at the expense of code speed.
+\end_layout
+
+\begin_layout Standard
+\begin_inset VSpace bigskip
+\end_inset
+
+
+\end_layout
+
+\begin_layout Subsection
+Other Options
+\begin_inset LatexCommand \index{Options other}
+
+\end_inset
+
+
\end_layout
\begin_layout List
\labelwidthstring 00.00.0000
\series bold
+-c\InsetSpace ~
-
\begin_inset ERT
status collapsed
\end_inset
--i-code-in-asm
-\begin_inset LatexCommand \index{-\/-i-code-in-asm}
+-compile-only
+\begin_inset LatexCommand \index{-\/-compile-only}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{-c -\/-compile-only}
\end_inset
\series default
- Include i-codes in the asm file.
- Sounds like noise but is most helpful for debugging the compiler itself.
+ will compile and assemble the source, but will not call the linkage editor.
\end_layout
\begin_layout List
\series bold
-
+\series default
+
\begin_inset ERT
status collapsed
\end_inset
--less-pedantic
-\begin_inset LatexCommand \index{-\/-less-pedantic}
+
+\series bold
+-c1mode
+\begin_inset LatexCommand \index{-\/-c1mode}
\end_inset
\series default
- Disable some of the more pedantic warnings
-\begin_inset LatexCommand \index{Warnings}
+ reads the preprocessed source from standard input and compiles it.
+ The file name for the assembler output must be specified using the -o option.
+\end_layout
+
+\begin_layout List
+\labelwidthstring 00.00.0000
+
+\series bold
+-E
+\begin_inset LatexCommand \index{-E}
\end_inset
- (jwk burps: please be more specific here, please!).
+
+\series default
+ Run only the C preprocessor.
+ Preprocess all the C source files specified and output the results to standard
+ output.
\end_layout
\begin_layout List
\labelwidthstring 00.00.0000
\series bold
--
-\begin_inset ERT
-status collapsed
+-o\InsetSpace ~
+<path/file>
+\begin_inset LatexCommand \index{-o <path/file>}
-\begin_layout Standard
+\end_inset
+
+
+\series default
+The output path where everything will be placed or the file name used for
+ all generated output files.
+ If the parameter is a path, it must have a trailing slash (or backslash
+ for the Windows binaries) to be recognized as a path.
+
+\emph on
+
+\emph default
+Note for Windows users: if the path contains spaces, it should be surrounded
+ by quotes.
+ The trailing backslash should be doubled in order to prevent escaping the
+ final quote, for example:
+\emph on
+-o
+\begin_inset Quotes sld
+\end_inset
+F:
+\backslash
+Projects
+\backslash
+test3
+\backslash
+output 1
+\backslash
\backslash
-/
-\end_layout
+\begin_inset Quotes srd
\end_inset
--disable-warning\InsetSpace ~
-<nnnn>
-\begin_inset LatexCommand \index{-\/-disable-warning}
+\emph default
+ or put after the final quote, for example:
+\emph on
+-o
+\begin_inset Quotes sld
+\end_inset
+
+F:
+\backslash
+Projects
+\backslash
+test3
+\backslash
+output 1
+\begin_inset Quotes srd
\end_inset
-\series default
- Disable specific warning with number <nnnn>.
+\backslash
+
+\emph default
+.
+ The path using slashes for directory delimiters can be used too, for example:
+
+\emph on
+-o
+\begin_inset Quotes sld
+\end_inset
+
+F:/Projects/test3/output 1/
+\begin_inset Quotes srd
+\end_inset
+
+
+\emph default
+.
\end_layout
\begin_layout List
\end_inset
--print-search-dirs
-\begin_inset LatexCommand \index{-\/-print-search-dirs}
+-stack-auto
+\begin_inset LatexCommand \index{-\/-stack-auto}
\end_inset
\series default
- Display the directories in the compiler's search path
-\end_layout
+\size large
+\emph on
-\begin_layout List
-\labelwidthstring 00.00.0000
+\size default
+\emph default
+All functions in the source file will be compiled as
+\emph on
+reentrant
+\emph default
+
+\begin_inset LatexCommand \index{reentrant}
+
+\end_inset
+
+, i.e.
+ the parameters and local variables will be allocated on the stack
+\begin_inset LatexCommand \index{stack}
+
+\end_inset
+
+.
+ See section
+\begin_inset LatexCommand \ref{sec:Parameters-and-Local-Variables}
+
+\end_inset
+ Parameters and Local Variables for more details.
+ If this option is used all source files in the project should be compiled
+ with this option.
+ It automatically implies -
\series bold
--
+
\begin_inset ERT
-status collapsed
+status open
\begin_layout Standard
\end_inset
--vc
-\begin_inset LatexCommand \index{-\/-vc}
-\end_inset
+\series default
+-int-long-reent and -
+\series bold
+\begin_inset ERT
+status open
-\series default
- Display errors and warnings using MSVC style, so you can use SDCC with
- the visual studio IDE
-\begin_inset LatexCommand \index{IDE}
+\begin_layout Standard
-\end_inset
-.
- With SDCC both offering a GCC-like (the default) and a MSVC-like
-\begin_inset LatexCommand \index{MSVC output style}
+\backslash
+/
+\end_layout
\end_inset
- output style, integration into most programming editors should be straightforwa
-rd.
+
+\series default
+-float-reent.
+
\end_layout
\begin_layout List
\end_inset
--use-stdout
-\begin_inset LatexCommand \index{-\/-use-stdout}
+-callee-saves
+\begin_inset LatexCommand \index{-\/-callee-saves}
+
+\end_inset
+
+
+\begin_inset LatexCommand \label{lyx:--callee-saves-function1[,function2][,function3]...}
\end_inset
+function1[,function2][,function3]....
\series default
- Send errors and warnings to stdout instead of stderr.
-\end_layout
+ The compiler by default uses a caller saves convention for register saving
+ across function calls, however this can cause unnecessary register pushing
+ and popping when calling small functions from larger functions.
+ This option can be used to switch the register saving convention for the
+ function names specified.
+ The compiler will not save registers when calling these functions, no extra
+ code will be generated at the entry and exit (function prologue
+\series bold
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_inset LatexCommand \index{function prologue}
+
+\end_inset
+
+\series default
+ and epilogue
\series bold
--Wa\InsetSpace ~
-asmOption[,asmOption]
+
+\begin_inset LatexCommand \index{function epilogue}
+
+\end_inset
+
+
\series default
+) for these functions to save and restore the registers used by these functions,
+ this can SUBSTANTIALLY reduce code and improve run time performance of
+ the generated code.
+ In the future the compiler (with inter procedural analysis) will be able
+ to determine the appropriate scheme to use for each function call.
+ DO NOT use this option for built-in functions such as _mulint..., if this
+ option is used for a library function the appropriate library function
+ needs to be recompiled with the same option.
+ If the project consists of multiple source files then all the source file
+ should be compiled with the same -
+\begin_inset ERT
+status collapsed
-\begin_inset LatexCommand \index{-Wa asmOption[,asmOption]}
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
\end_inset
-...
- Pass the asmOption to the assembler
-\begin_inset LatexCommand \index{Options assembler}
+-callee-saves option string.
+ Also see #pragma\InsetSpace ~
+callee_saves
+\begin_inset LatexCommand \index{\#pragma callee\_saves}
\end_inset
-\begin_inset LatexCommand \index{Assembler options}
+\begin_inset LatexCommand \vpageref{ite:callee_saves-function1[,function2[,function3...]]--}
\end_inset
.
- See file sdcc/as/doc/asxhtm.html for assembler options.cd
\end_layout
\begin_layout List
\end_inset
--std-sdcc89
-\begin_inset LatexCommand \index{-\/-std-sdcc89}
+-all-callee-saves
+\begin_inset LatexCommand \index{-\/-all-callee-saves}
\end_inset
\series default
- Generally follow the C89 standard, but allow SDCC features that conflict
- with the standard (default).
-\end_layout
-
-\begin_layout List
-\labelwidthstring 00.00.0000
-
+Function of
\series bold
+
+\series default
-
\begin_inset ERT
status collapsed
\end_inset
--std-c89
-\begin_inset LatexCommand \index{-\/-std-c89}
-
-\end_inset
-
-
-\series default
- Follow the C89 standard and disable SDCC features that conflict with the
- standard.
+-callee-saves will be applied to all functions by default.
\end_layout
\begin_layout List
\end_inset
--std-sdcc99
-\begin_inset LatexCommand \index{-\/-std-sdcc99}
+-debug
+\begin_inset LatexCommand \index{-\/-debug}
\end_inset
+\bar under
+
\series default
- Generally follow the C99 standard, but allow SDCC features that conflict
- with the standard (incomplete support).
+\bar default
+When this option is used the compiler will generate debug information.
+ The debug information collected in a file with .cdb extension can be used
+ with the SDCDB.
+ For more information see documentation for SDCDB.
+ Another file with no extension contains debug information in AOMF or AOMF51
+\begin_inset LatexCommand \index{AOMF, AOMF51}
+
+\end_inset
+
+ format which is commonly used by third party tools.
+\end_layout
+
+\begin_layout List
+\labelwidthstring 00.00.0000
+
+\series bold
+-S
+\begin_inset LatexCommand \index{-S}
+
+\end_inset
+
+
+\size large
+\bar under
+
+\series default
+\size default
+\bar default
+Stop after the stage of compilation proper; do not assemble.
+ The output is an assembler code file for the input file specified.
\end_layout
\begin_layout List
\end_inset
--std-c99
-\begin_inset LatexCommand \index{-\/-std-sdcc99}
+-int-long-reent
+\begin_inset LatexCommand \index{-\/-int-long-reent}
\end_inset
\series default
- Follow the C99 standard and disable SDCC features that conflict with the
- standard (incomplete support).
+ Integer (16 bit) and long (32 bit) libraries have been compiled as reentrant.
+ Note by default these libraries are compiled as non-reentrant.
+ See section Installation for more details.
\end_layout
\begin_layout List
\end_inset
--codeseg
-\series default
-
-\begin_inset LatexCommand \index{-\/-codeseg <Value>}
+-cyclomatic
+\begin_inset LatexCommand \index{-\/-cyclomatic}
\end_inset
-\InsetSpace ~
-<Name> The name to be used for the code
-\begin_inset LatexCommand \index{code}
+
+\bar under
+
+\series default
+\bar default
+This option will cause the compiler to generate an information message for
+ each function in the source file.
+ The message contains some
+\emph on
+important
+\emph default
+ information about the function.
+ The number of edges and nodes the compiler detected in the control flow
+ graph of the function, and most importantly the
+\emph on
+cyclomatic complexity
+\begin_inset LatexCommand \index{Cyclomatic complexity}
\end_inset
- segment, default CSEG.
- This is useful if you need to tell the compiler to put the code in a special
- segment so you can later on tell the linker to put this segment in a special
- place in memory.
- Can be used for instance when using bank switching to put the code in a
- bank.
+
+\emph default
+ see section on Cyclomatic Complexity for more details.
\end_layout
\begin_layout List
\end_inset
--constseg
-\series default
-
-\begin_inset LatexCommand \index{-\/-constseg <Value>}
+-float-reent
+\begin_inset LatexCommand \index{-\/-float-reent}
\end_inset
-\InsetSpace ~
-<Name> The name to be used for the const
-\begin_inset LatexCommand \index{code}
+
+\series default
+ Floating point library is compiled as reentrant
+\begin_inset LatexCommand \index{reentrant}
\end_inset
- segment, default CONST.
- This is useful if you need to tell the compiler to put the const data in
- a special segment so you can later on tell the linker to put this segment
- in a special place in memory.
- Can be used for instance when using bank switching to put the const data
- in a bank.
+.
+ See section Installation for more details.
\end_layout
\begin_layout List
\end_inset
--fdollars-in-identifiers
-\begin_inset LatexCommand \index{-\/-fdollars-in-identifiers}
+-funsigned-char
+\begin_inset LatexCommand \index{-\/-funsigned-char}
\end_inset
\series default
- Permit '$' as an identifier character
-\end_layout
-
-\begin_layout List
-\labelwidthstring 00.00.0000
-
-\series bold
-more-pedantic
-\series default
- Actually this is
-\series bold
-\emph on
-not
-\series default
-\emph default
- a SDCC compiler option but if you want
-\emph on
-more
-\emph default
- warnings you can use a separate tool dedicated to syntax checking like
- splint
-\begin_inset LatexCommand \label{lyx:more-pedantic-SPLINT}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{lint (syntax checking tool)}
-
-\end_inset
-
-
-\begin_inset LatexCommand \url{http://www.splint.org}
-
-\end_inset
-
-.
- To make your source files parseable by splint you will have to include
-
-\family sans
-lint.h
+ The default signedness for every type is
+\family typewriter
+ signed
\family default
-
-\begin_inset LatexCommand \index{splint (syntax checking tool)}
-
-\end_inset
-
- in your source file and add brackets around extended keywords (like
-\family sans
-
-\begin_inset Quotes sld
-\end_inset
-
-__at\InsetSpace ~
-
-\series bold
-(
-\series default
-0xab
-\series bold
-)
-\series default
-
-\begin_inset Quotes srd
-\end_inset
-
-
+.
+ In some embedded environments the default signedness of
+\family typewriter
+ char
\family default
- and
-\family sans
-
-\begin_inset Quotes sld
-\end_inset
-
-__interrupt\InsetSpace ~
-(2)
-\begin_inset Quotes srd
-\end_inset
-
-
+ is
+\family typewriter
+ unsigned
\family default
-).
-
-\newline
-Splint has an excellent on line manual at
-\begin_inset LatexCommand \url{http://www.splint.org/manual/}
-
-\end_inset
-
- and it's capabilities go beyond pure syntax checking.
- You'll need to tell splint the location of SDCC's include files so a typical
- command line could look like this:
-\newline
+.
+ To set the signess for characters to unsigned, use the option -
+\series bold
-\family sans
-splint\InsetSpace ~
--I\InsetSpace ~
-/usr/local/share/sdcc/include/mcs51/\InsetSpace ~
-\InsetSpace ~
-myprogram.c
-\end_layout
+\begin_inset ERT
+status open
\begin_layout Standard
-\begin_inset VSpace bigskip
-\end_inset
-
-
-\end_layout
-
-\begin_layout Subsection
-Intermediate Dump Options
-\begin_inset LatexCommand \label{sub:Intermediate-Dump-Options}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{Options intermediate dump}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{Intermediate dump options}
-
-\end_inset
+\backslash
+/
\end_layout
-\begin_layout Standard
-The following options are provided for the purpose of retargetting and debugging
- the compiler.
- They provide a means to dump the intermediate code (iCode
-\begin_inset LatexCommand \index{iCode}
-
-\end_inset
-
-) generated by the compiler in human readable form at various stages of
- the compilation process.
- More on iCodes see chapter
-\begin_inset LatexCommand \ref{sub:The-anatomy-of}
-
-\end_inset
-
-
-\begin_inset Quotes srd
\end_inset
-The anatomy of the compiler
-\begin_inset Quotes srd
-\end_inset
-.
+\series default
+-funsigned-char.
+ If this option is set and no signedness keyword (unsigned/signed) is given,
+ a char will be signed.
+ All other types are unaffected.
\end_layout
\begin_layout List
\end_inset
--dumpraw
-\begin_inset LatexCommand \index{-\/-dumpraw}
+-main-return
+\begin_inset LatexCommand \index{-\/-main-return}
\end_inset
\series default
- This option will cause the compiler to dump the intermediate code into
- a file of named
-\emph on
-<source filename>.dumpraw
-\emph default
- just after the intermediate code has been generated for a function, i.e.
- before any optimizations are done.
- The basic blocks
-\begin_inset LatexCommand \index{Basic blocks}
+ This option can be used if the code generated is called by a monitor program
+ or if the main routine includes an endless loop.
+ This option results in slightly smaller code and saves two bytes of stack
+ space.
+ The return from the 'main'
+\begin_inset LatexCommand \index{main return}
\end_inset
- at this stage ordered in the depth first number, so they may not be in
- sequence of execution.
+ function will return to the function calling main.
+ The default setting is to lock up i.e.
+ generate a '
+\family typewriter
+sjmp .
+\family default
+'.
\end_layout
\begin_layout List
\end_inset
--dumpgcse
-\begin_inset LatexCommand \index{-\/-dumpgcse}
+-nostdinc
+\begin_inset LatexCommand \index{-\/-nostdinc}
\end_inset
\series default
- Will create a dump of iCode's, after global subexpression elimination
-\begin_inset LatexCommand \index{Global subexpression elimination}
-
-\end_inset
-
-, into a file named
-\emph on
-<source filename>.dumpgcse.
+ This will prevent the compiler from passing on the default include path
+ to the preprocessor.
\end_layout
\begin_layout List
\end_inset
--dumpdeadcode
-\begin_inset LatexCommand \index{-\/-dumpdeadcode}
+-nostdlib
+\begin_inset LatexCommand \index{-\/-nostdlib}
\end_inset
\series default
- Will create a dump of iCode's, after deadcode elimination
-\begin_inset LatexCommand \index{Dead-code elimination}
+ This will prevent the compiler from passing on the default library
+\begin_inset LatexCommand \index{Libraries}
\end_inset
-, into a file named
-\emph on
-<source filename>.dumpdeadcode.
+ path to the linker.
\end_layout
\begin_layout List
\end_inset
--dumploop
-\begin_inset LatexCommand \index{-\/-dumploop}
+-verbose
+\begin_inset LatexCommand \index{-\/-verbose}
\end_inset
\series default
-\size large
-
-\size default
-Will create a dump of iCode's, after loop optimizations
-\begin_inset LatexCommand \index{Loop optimization}
+ Shows the various actions the compiler is performing.
+\end_layout
+
+\begin_layout List
+\labelwidthstring 00.00.0000
+
+\series bold
+-V
+\begin_inset LatexCommand \index{-V}
\end_inset
-, into a file named
-\emph on
-<source filename>.dumploop.
+
+\series default
+ Shows the actual commands the compiler is executing.
\end_layout
\begin_layout List
\end_inset
--dumprange
-\begin_inset LatexCommand \index{-\/-dumprange}
+-no-c-code-in-asm
+\begin_inset LatexCommand \index{-\/-no-c-code-in-asm}
\end_inset
\series default
-\size large
-
-\size default
-Will create a dump of iCode's, after live range analysis
-\begin_inset LatexCommand \index{Live range analysis}
-
-\end_inset
-
-, into a file named
-\emph on
-<source filename>.dumprange.
+ Hides your ugly and inefficient c-code from the asm file, so you can always
+ blame the compiler :)
\end_layout
\begin_layout List
\end_inset
--dumlrange
-\begin_inset LatexCommand \index{-\/-dumlrange}
+-fverbose-asm
+\begin_inset LatexCommand \index{-\/-no-gen-comments}
\end_inset
\series default
- Will dump the life ranges
-\begin_inset LatexCommand \index{Live range analysis}
-
-\end_inset
-
- for all symbols.
+ Include code generator and peep-hole comments in the generated asm files.
\end_layout
\begin_layout List
\end_inset
--dumpregassign
-\begin_inset LatexCommand \index{-\/-dumpregassign}
+-no-peep-comments
+\begin_inset LatexCommand \index{-\/-no-peep-comments}
\end_inset
-\bar under
-
\series default
-\bar default
-Will create a dump of iCode's, after register assignment
-\begin_inset LatexCommand \index{Register assignment}
+ Don't include peep-hole comments in the generated asm files even if -
+\series bold
+
+\begin_inset ERT
+status open
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
\end_inset
-, into a file named
-\emph on
-<source filename>.dumprassgn.
+
+\series default
+-fverbose-asm option is specified.
\end_layout
\begin_layout List
\end_inset
--dumplrange
-\begin_inset LatexCommand \index{-\/-dumplrange}
+-i-code-in-asm
+\begin_inset LatexCommand \index{-\/-i-code-in-asm}
\end_inset
\series default
- Will create a dump of the live ranges of iTemp's
+ Include i-codes in the asm file.
+ Sounds like noise but is most helpful for debugging the compiler itself.
\end_layout
\begin_layout List
\end_inset
--dumpall
-\begin_inset LatexCommand \index{-\/-dumpall}
+-less-pedantic
+\begin_inset LatexCommand \index{pedantic}
\end_inset
-\size large
-\bar under
-
-\series default
-\size default
-\bar default
-Will cause all the above mentioned dumps to be created.
-\end_layout
+\begin_inset LatexCommand \index{-\/-less-pedantic}
-\begin_layout Standard
-\begin_inset VSpace bigskip
\end_inset
-\end_layout
+\series default
-\begin_layout Subsection
-Redirecting output on Windows Shells
-\end_layout
+\begin_inset LatexCommand \label{lyx:--less-pedantic}
-\begin_layout Standard
-By default SDCC writes it's error messages to
-\begin_inset Quotes sld
\end_inset
-standard error
-\begin_inset Quotes srd
+ Disable some of the more pedantic warnings
+\begin_inset LatexCommand \index{Warnings}
+
\end_inset
.
- To force all messages to
-\begin_inset Quotes sld
-\end_inset
+ For more details, see the less_pedantic pragma
+\begin_inset LatexCommand \vpageref{ite:less_pedantic}
-standard output
-\begin_inset Quotes srd
\end_inset
- use
+.
+\end_layout
+
+\begin_layout List
+\labelwidthstring 00.00.0000
+
\series bold
-
-\series default
-\emph on
-
\begin_inset ERT
status collapsed
\end_inset
-
-\series bold
-\emph default
--
-\series default
-use-stdout
-\begin_inset LatexCommand \index{-\/-use-stdout}
+-disable-warning\InsetSpace ~
+<nnnn>
+\begin_inset LatexCommand \index{-\/-disable-warning}
\end_inset
-.
- Additionally, if you happen to have visual studio installed in your windows
- machine, you can use it to compile your sources using a custom build and
- the SDCC -
-\emph on
+\series default
+ Disable specific warning with number <nnnn>.
+\end_layout
+
+\begin_layout List
+\labelwidthstring 00.00.0000
+
+\series bold
+-
\begin_inset ERT
status collapsed
\end_inset
-
-\emph default
--vc
-\begin_inset LatexCommand \index{-\/-vc}
+-Werror
+\begin_inset LatexCommand \index{-\/-Werror}
\end_inset
- option.
- Something like this should work:
-\newline
-
-\newline
-\series bold
-c:
-\backslash
-sdcc
-\backslash
-bin
-\backslash
-sdcc.exe -
\series default
-\emph on
+ Treat all warnings as errors.
+\end_layout
+
+\begin_layout List
+\labelwidthstring 00.00.0000
+\series bold
+-
\begin_inset ERT
status collapsed
\end_inset
+-print-search-dirs
+\begin_inset LatexCommand \index{-\/-print-search-dirs}
+
+\end_inset
+
-\series bold
-\emph default
--vc -
\series default
-\emph on
+ Display the directories in the compiler's search path
+\end_layout
+
+\begin_layout List
+\labelwidthstring 00.00.0000
+\series bold
+-
\begin_inset ERT
status collapsed
\end_inset
+-vc
+\begin_inset LatexCommand \index{-\/-vc}
-\series bold
-\emph default
--model-large -c $(InputPath)
-\series default
-
-\begin_inset VSpace bigskip
\end_inset
-\end_layout
-
-\begin_layout Section
-Environment variables
-\begin_inset LatexCommand \index{Environment variables}
+\series default
+ Display errors and warnings using MSVC style, so you can use SDCC with
+ the visual studio IDE
+\begin_inset LatexCommand \index{IDE}
\end_inset
+.
+ With SDCC both offering a GCC-like (the default) and a MSVC-like
+\begin_inset LatexCommand \index{MSVC output style}
-\end_layout
+\end_inset
-\begin_layout Standard
-SDCC recognizes the following environment variables:
+ output style, integration into most programming editors should be straightforwa
+rd.
\end_layout
\begin_layout List
\labelwidthstring 00.00.0000
\series bold
-SDCC_LEAVE_SIGNALS
-\begin_inset LatexCommand \index{SDCC\_LEAVE\_SIGNALS}
-
-\end_inset
-
+-
+\begin_inset ERT
+status collapsed
-\series default
- SDCC installs a signal handler
-\begin_inset LatexCommand \index{signal handler}
+\begin_layout Standard
-\end_inset
- to be able to delete temporary files after an user break (^C) or an exception.
- If this environment variable is set, SDCC won't install the signal handler
- in order to be able to debug SDCC.
+\backslash
+/
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\end_inset
-\series bold
-TMP,\InsetSpace ~
-TEMP,\InsetSpace ~
-TMPDIR
-\begin_inset LatexCommand \index{TMP, TEMP, TMPDIR}
+-use-stdout
+\begin_inset LatexCommand \index{-\/-use-stdout}
\end_inset
\series default
- Path, where temporary files will be created.
- The order of the variables is the search order.
- In a standard *nix environment these variables are not set, and there's
- no need to set them.
- On Windows it's recommended to set one of them.
+ Send errors and warnings to stdout instead of stderr.
\end_layout
\begin_layout List
\labelwidthstring 00.00.0000
\series bold
-SDCC_HOME
-\begin_inset LatexCommand \index{SDCC\_HOME}
+-Wa\InsetSpace ~
+asmOption[,asmOption]
+\series default
-\end_inset
+\begin_inset LatexCommand \index{-Wa asmOption[,asmOption]}
+\end_inset
-\series default
- Path, see section
-\begin_inset LatexCommand \ref{sub:Install-paths}
+...
+ Pass the asmOption to the assembler
+\begin_inset LatexCommand \index{Options assembler}
\end_inset
-\InsetSpace ~
-\begin_inset Quotes sld
-\end_inset
+\begin_inset LatexCommand \index{Assembler options}
- Install Paths
-\begin_inset Quotes srd
\end_inset
.
+ See file sdcc/as/doc/asxhtm.html for assembler options.cd
\end_layout
\begin_layout List
\labelwidthstring 00.00.0000
\series bold
-SDCC_INCLUDE
-\begin_inset LatexCommand \index{SDCC\_INCLUDE}
+-
+\begin_inset ERT
+status collapsed
-\end_inset
+\begin_layout Standard
-\series default
- Path, see section
-\begin_inset LatexCommand \ref{sub:Search-Paths}
+\backslash
+/
+\end_layout
\end_inset
-\InsetSpace ~
+-std-sdcc89
+\begin_inset LatexCommand \index{-\/-std-sdcc89}
-\begin_inset Quotes sld
\end_inset
-Search Paths
-\begin_inset Quotes srd
-\end_inset
-.
+\series default
+ Generally follow the C89 standard, but allow SDCC features that conflict
+ with the standard (default).
\end_layout
\begin_layout List
\labelwidthstring 00.00.0000
\series bold
-SDCC_LIB
-\begin_inset LatexCommand \index{SDCC\_LIB}
+-
+\begin_inset ERT
+status collapsed
-\end_inset
+\begin_layout Standard
-\series default
- Path, see section
-\begin_inset LatexCommand \ref{sub:Search-Paths}
+\backslash
+/
+\end_layout
\end_inset
-\InsetSpace ~
+-std-c89
+\begin_inset LatexCommand \index{-\/-std-c89}
-\begin_inset Quotes sld
\end_inset
-Search Paths
-\begin_inset Quotes srd
-\end_inset
-..
+\series default
+ Follow the C89 standard and disable SDCC features that conflict with the
+ standard.
\end_layout
+\begin_layout List
+\labelwidthstring 00.00.0000
+
+\series bold
+-
+\begin_inset ERT
+status collapsed
+
\begin_layout Standard
-There are some more environment variables recognized by SDCC, but these
- are solely used for debugging purposes.
- They can change or disappear very quickly, and will never be documented.
-\begin_inset VSpace bigskip
-\end_inset
+\backslash
+/
\end_layout
-\begin_layout Section
-Storage Class Language Extensions
-\end_layout
+\end_inset
-\begin_layout Subsection
-MCS51/DS390 Storage Class
-\begin_inset LatexCommand \index{Storage class}
+-std-sdcc99
+\begin_inset LatexCommand \index{-\/-std-sdcc99}
\end_inset
- Language Extensions
-\end_layout
-\begin_layout Standard
-In addition to the ANSI storage classes SDCC allows the following MCS51
- specific storage classes:
+\series default
+ Generally follow the C99 standard, but allow SDCC features that conflict
+ with the standard (incomplete support).
\end_layout
-\begin_layout Subsubsection
-data
-\begin_inset LatexCommand \index{data (mcs51, ds390 storage class)}
-
-\end_inset
+\begin_layout List
+\labelwidthstring 00.00.0000
+\series bold
+-
+\begin_inset ERT
+status collapsed
-\begin_inset LatexCommand \index{\_\_data (mcs51, ds390 storage class)}
+\begin_layout Standard
-\end_inset
- / near
-\begin_inset LatexCommand \index{near (storage class)}
+\backslash
+/
+\end_layout
\end_inset
-
-\begin_inset LatexCommand \index{\_\_near (storage class)}
+-std-c99
+\begin_inset LatexCommand \index{-\/-std-sdcc99}
\end_inset
-\end_layout
-
-\begin_layout Standard
-This is the
-\series bold
-default
\series default
- storage class for the Small Memory model (
-\emph on
-data
-\emph default
- and
-\emph on
-near
-\emph default
- or the more ANSI-C compliant forms
-\emph on
-__data
-\emph default
- and
-\emph on
-__near
-\emph default
- can be used synonymously).
- Variables declared with this storage class will be allocated in the directly
- addressable portion of the internal RAM of a 8051, e.g.:
+ Follow the C99 standard and disable SDCC features that conflict with the
+ standard (incomplete support).
\end_layout
-\begin_layout Verse
+\begin_layout List
+\labelwidthstring 00.00.0000
-\family typewriter
-__data unsigned char test_data;
-\end_layout
+\series bold
+-
+\begin_inset ERT
+status collapsed
\begin_layout Standard
-Writing 0x01 to this variable generates the assembly code:
-\end_layout
-\begin_layout Verse
-\family typewriter
-75*00 01\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-mov\InsetSpace ~
-\InsetSpace ~
-_test_data,#0x01
+\backslash
+/
\end_layout
-\begin_layout Subsubsection
-xdata
-\begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
-
\end_inset
+-codeseg
+\series default
-\begin_inset LatexCommand \index{\_\_xdata (mcs51, ds390 storage class)}
+\begin_inset LatexCommand \index{-\/-codeseg <Value>}
\end_inset
- / far
-\begin_inset LatexCommand \index{far (storage class)}
+\InsetSpace ~
+<Name> The name to be used for the code
+\begin_inset LatexCommand \index{code}
\end_inset
+ segment, default CSEG.
+ This is useful if you need to tell the compiler to put the code in a special
+ segment so you can later on tell the linker to put this segment in a special
+ place in memory.
+ Can be used for instance when using bank switching to put the code in a
+ bank.
+\end_layout
-\begin_inset LatexCommand \index{\_\_far (storage class)}
+\begin_layout List
+\labelwidthstring 00.00.0000
-\end_inset
+\series bold
+-
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+\backslash
+/
\end_layout
-\begin_layout Standard
-Variables declared with this storage class will be placed in the external
- RAM.
- This is the
-\series bold
-default
+\end_inset
+
+-constseg
\series default
- storage class for the Large Memory model, e.g.:
-\end_layout
-\begin_layout Verse
+\begin_inset LatexCommand \index{-\/-constseg <Value>}
-\family typewriter
-__xdata unsigned char test_xdata;
+\end_inset
+
+\InsetSpace ~
+<Name> The name to be used for the const
+\begin_inset LatexCommand \index{const}
+
+\end_inset
+
+ segment, default CONST.
+ This is useful if you need to tell the compiler to put the const data in
+ a special segment so you can later on tell the linker to put this segment
+ in a special place in memory.
+ Can be used for instance when using bank switching to put the const data
+ in a bank.
\end_layout
+\begin_layout List
+\labelwidthstring 00.00.0000
+
+\series bold
+-
+\begin_inset ERT
+status collapsed
+
\begin_layout Standard
-Writing 0x01 to this variable generates the assembly code:
-\end_layout
-\begin_layout Verse
-\family typewriter
-90s00r00\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-mov\InsetSpace ~
-\InsetSpace ~
-dptr,#_test_xdata
-\newline
-74\InsetSpace ~
-01\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-mov\InsetSpace ~
-\InsetSpace ~
-a,#0x01
-\newline
-F0\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-movx\InsetSpace ~
-@dptr,a
+\backslash
+/
\end_layout
-\begin_layout Subsubsection
-idata
-\begin_inset LatexCommand \index{idata (mcs51, ds390 storage class)}
-
\end_inset
-
-\begin_inset LatexCommand \index{\_\_idata (mcs51, ds390 storage class)}
+-fdollars-in-identifiers
+\begin_inset LatexCommand \index{-\/-fdollars-in-identifiers}
\end_inset
+\series default
+ Permit '$' as an identifier character.
\end_layout
+\begin_layout List
+\labelwidthstring 00.00.0000
+
+\series bold
+-
+\begin_inset ERT
+status collapsed
+
\begin_layout Standard
-Variables declared with this storage class will be allocated into the indirectly
- addressable portion of the internal ram of a 8051, e.g.:
-\end_layout
-\begin_layout Verse
-\family typewriter
-__idata unsigned char test_idata;
+\backslash
+/
\end_layout
-\begin_layout Standard
-Writing 0x01 to this variable generates the assembly code:
-\end_layout
+\end_inset
-\begin_layout Verse
+-more-pedantic
+\series default
-\family typewriter
-78r00\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-mov\InsetSpace ~
-\InsetSpace ~
-r0,#_test_idata
-\newline
-76\InsetSpace ~
-01\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-mov\InsetSpace ~
-\InsetSpace ~
-@r0,#0x01
-\end_layout
+\begin_inset LatexCommand \index{-\/-more-pedantic}
-\begin_layout Standard
-Please note, the first 128 byte of idata physically access the same RAM
- as the data memory.
- The original 8051 had 128 byte idata memory, nowadays most devices have
- 256 byte idata memory.
- The stack
-\begin_inset LatexCommand \index{stack}
+\end_inset
+
+
+\begin_inset LatexCommand \index{pedantic}
\end_inset
- is located in idata memory.
-\end_layout
+ Actually this is
+\series bold
+\emph on
+not
+\series default
+\emph default
+ a SDCC compiler option but if you want
+\emph on
+more
+\emph default
+ warnings you can use a separate tool dedicated to syntax checking like
+ splint
+\begin_inset LatexCommand \label{lyx:more-pedantic-SPLINT}
+
+\end_inset
-\begin_layout Subsubsection
-pdata
-\begin_inset LatexCommand \index{pdata (mcs51, ds390 storage class)}
+
+\begin_inset LatexCommand \index{lint (syntax checking tool)}
\end_inset
-\begin_inset LatexCommand \index{\_\_pdata (mcs51, ds390 storage class)}
+\begin_inset LatexCommand \url{http://www.splint.org}
\end_inset
+.
+ To make your source files parseable by splint you will have to include
-\end_layout
+\family sans
+lint.h
+\family default
-\begin_layout Standard
-Paged xdata access is just as straightforward as using the other addressing
- modes of a 8051.
- It is typically located at the start of xdata and has a maximum size of
- 256 bytes.
- The following example writes 0x01 to the pdata variable.
- Please note, pdata access physically accesses xdata memory.
- The high byte of the address is determined by port P2
-\begin_inset LatexCommand \index{P2 (mcs51 sfr)}
+\begin_inset LatexCommand \index{splint (syntax checking tool)}
\end_inset
-(or in case of some 8051 variants by a separate Special Function Register,
- see section
-\begin_inset LatexCommand \ref{sub:MCS51-variants}
+ in your source file and add brackets around extended keywords (like
+\family sans
+\begin_inset Quotes sld
\end_inset
-).
- This is the
+__at\InsetSpace ~
+
\series bold
-default
+(
+\series default
+0xab
+\series bold
+)
\series default
- storage class for the Medium Memory model, e.g.:
-\end_layout
-\begin_layout Verse
+\begin_inset Quotes srd
+\end_inset
-\family typewriter
-__pdata unsigned char test_pdata;
-\end_layout
-\begin_layout Standard
-Writing 0x01 to this variable generates the assembly code:
-\end_layout
+\family default
+ and
+\family sans
-\begin_layout Verse
+\begin_inset Quotes sld
+\end_inset
+
+__interrupt\InsetSpace ~
+(2)
+\begin_inset Quotes srd
+\end_inset
+
+
+\family default
+).
-\family typewriter
-78r00\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-mov r0,#_test_pdata
\newline
-74 01\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-mov a,#0x01
+Splint has an excellent on line manual at
+\begin_inset LatexCommand \url{http://www.splint.org/manual/}
+
+\end_inset
+
+ and it's capabilities go beyond pure syntax checking.
+ You'll need to tell splint the location of SDCC's include files so a typical
+ command line could look like this:
\newline
-F2\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
+
+\family sans
+splint\InsetSpace ~
+-I\InsetSpace ~
+/usr/local/share/sdcc/include/mcs51/\InsetSpace ~
\InsetSpace ~
-movx @r0,a
+myprogram.c
\end_layout
-\begin_layout Standard
-If the -
+\begin_layout List
+\labelwidthstring 00.00.0000
+
+\series bold
+-
\begin_inset ERT
status collapsed
\end_inset
--xstack
-\begin_inset LatexCommand \index{-\/-xstack}
+-short-is-8bits
+\series default
+
+\begin_inset LatexCommand \index{-\/-short-is-8bits}
\end_inset
- option is used the pdata memory area is followed by the xstack memory area
- and the sum of their sizes is limited to 256 bytes.
-\end_layout
-\begin_layout Subsubsection
-code
-\begin_inset LatexCommand \index{code}
+\begin_inset LatexCommand \label{lyx:--short-is-8bits}
\end_inset
-
-\begin_inset LatexCommand \index{\_\_code}
+ Treat short as 8-bit (for backward compatibility with older versions of
+ compiler - see section
+\begin_inset LatexCommand \ref{sec:Compatibility-with-previous}
\end_inset
-
+)
\end_layout
\begin_layout Standard
-'Variables' declared with this storage class will be placed in the code
- memory:
-\end_layout
-
-\begin_layout Verse
+\begin_inset VSpace bigskip
+\end_inset
-\family typewriter
-__code unsigned char test_code;
-\end_layout
-\begin_layout Standard
-Read access to this variable generates the assembly code:
\end_layout
-\begin_layout Verse
-
-\family typewriter
-90s00r6F\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-mov dptr,#_test_code
-\newline
-E4\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-clr a
-\newline
-93\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-movc a,@a+dptr
-\end_layout
+\begin_layout Subsection
+Intermediate Dump Options
+\begin_inset LatexCommand \label{sub:Intermediate-Dump-Options}
-\begin_layout Standard
+\end_inset
-\family typewriter
-char
-\family default
- indexed arrays of characters in code memory can be accessed efficiently:
-\end_layout
-\begin_layout Verse
+\begin_inset LatexCommand \index{Options intermediate dump}
-\family typewriter
-__code char test_array[] = {'c','h','e','a','p'};
-\end_layout
+\end_inset
-\begin_layout Standard
-Read access to this array using an 8-bit unsigned index generates the assembly
- code:
-\end_layout
-\begin_layout Verse
+\begin_inset LatexCommand \index{Intermediate dump options}
-\family typewriter
-E5*00\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-mov a,_index
-\end_layout
+\end_inset
-\begin_layout Verse
-\family typewriter
-90s00r41\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-mov dptr,#_test_array
\end_layout
-\begin_layout Verse
+\begin_layout Standard
+The following options are provided for the purpose of retargetting and debugging
+ the compiler.
+ They provide a means to dump the intermediate code (iCode
+\begin_inset LatexCommand \index{iCode}
-\family typewriter
-93\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-movc a,@a+dptr
-\end_layout
+\end_inset
-\begin_layout Subsubsection
-bit
-\begin_inset LatexCommand \index{bit}
+) generated by the compiler in human readable form at various stages of
+ the compilation process.
+ More on iCodes see chapter
+\begin_inset LatexCommand \ref{sub:The-anatomy-of}
\end_inset
-\begin_inset LatexCommand \index{\_\_bit}
-
+\begin_inset Quotes srd
\end_inset
+The anatomy of the compiler
+\begin_inset Quotes srd
+\end_inset
+.
\end_layout
-\begin_layout Standard
-This is a data-type and a storage class specifier.
- When a variable is declared as a bit, it is allocated into the bit addressable
- memory of 8051, e.g.:
-\end_layout
-
-\begin_layout Verse
+\begin_layout List
+\labelwidthstring 00.00.0000
-\family typewriter
-__bit test_bit;
-\end_layout
+\series bold
+-
+\begin_inset ERT
+status collapsed
\begin_layout Standard
-Writing 1 to this variable generates the assembly code:
-\end_layout
-\begin_layout Verse
-\family typewriter
-D2*00\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-setb\InsetSpace ~
-_test_bit
+\backslash
+/
\end_layout
-\begin_layout Standard
-The bit addressable memory consists of 128 bits which are located from 0x20
- to 0x2f in data memory.
-
-\newline
-Apart from this 8051 specific storage class most architectures support
- ANSI-C bitfields
-\begin_inset LatexCommand \index{bitfields}
-
\end_inset
-
-\begin_inset Foot
-status open
-
-\begin_layout Standard
-Not really meant as examples, but nevertheless showing what bitfields are
- about: device/include/mc68hc908qy.h and support/regression/tests/bitfields.c
-\end_layout
+-dumpraw
+\begin_inset LatexCommand \index{-\/-dumpraw}
\end_inset
-.
- In accordance with ISO/IEC 9899 bits and bitfields without an explicit
- signed modifier are implemented as unsigned.
-\end_layout
-\begin_layout Subsubsection
-sfr
-\begin_inset LatexCommand \index{sfr}
+\series default
+ This option will cause the compiler to dump the intermediate code into
+ a file of named
+\emph on
+<source filename>.dumpraw
+\emph default
+ just after the intermediate code has been generated for a function, i.e.
+ before any optimizations are done.
+ The basic blocks
+\begin_inset LatexCommand \index{Basic blocks}
\end_inset
+ at this stage ordered in the depth first number, so they may not be in
+ sequence of execution.
+\end_layout
-\begin_inset LatexCommand \index{\_\_sfr}
-
-\end_inset
+\begin_layout List
+\labelwidthstring 00.00.0000
- / sfr16
-\begin_inset LatexCommand \index{sfr16}
+\series bold
+-
+\begin_inset ERT
+status collapsed
-\end_inset
+\begin_layout Standard
-\begin_inset LatexCommand \index{\_\_sfr16}
+\backslash
+/
+\end_layout
\end_inset
- / sfr32
-\begin_inset LatexCommand \index{sfr32}
+-dumpgcse
+\begin_inset LatexCommand \index{-\/-dumpgcse}
\end_inset
-\begin_inset LatexCommand \index{\_\_sfr32}
-
-\end_inset
-
- / sbit
-\begin_inset LatexCommand \index{\_\_sbit}
+\series default
+ Will create a dump of iCodes, after global subexpression elimination
+\begin_inset LatexCommand \index{Global subexpression elimination}
\end_inset
+, into a file named
+\emph on
+<source filename>.dumpgcse.
+\end_layout
-\begin_inset LatexCommand \index{sbit}
+\begin_layout List
+\labelwidthstring 00.00.0000
-\end_inset
+\series bold
+-
+\begin_inset ERT
+status collapsed
+\begin_layout Standard
-\end_layout
-\begin_layout Standard
-Like the bit keyword,
-\emph on
-sfr / sfr16 / sfr32 / sbit
-\emph default
-signify both a data-type and storage class, they are used to describe the
-
-\emph on
-s
-\emph default
-pecial
-\emph on
-f
-\emph default
-unction
-\emph on
-r
-\emph default
-egisters and
-\emph on
-s
-\emph default
-pecial
-\emph on
-bit
-\emph default
- variables of a 8051, eg:
+\backslash
+/
\end_layout
-\begin_layout Verse
+\end_inset
-\family typewriter
-__sfr __at
-\begin_inset LatexCommand \index{at}
+-dumpdeadcode
+\begin_inset LatexCommand \index{-\/-dumpdeadcode}
\end_inset
-\begin_inset LatexCommand \index{\_\_at}
+\series default
+ Will create a dump of iCodes, after deadcode elimination
+\begin_inset LatexCommand \index{Dead-code elimination}
\end_inset
- (0x80) P0;\InsetSpace ~
- /* special function register P0 at location 0x80 */
-\newline
+, into a file named
+\emph on
+<source filename>.dumpdeadcode.
+\end_layout
-\newline
-/* 16 bit
- special function register combination for timer 0
-\newline
-\InsetSpace ~
-\InsetSpace ~
- with the high byte at
- location 0x8C and the low byte at location 0x8A */
-\newline
-__sfr16 __at (0x8C8A)
- TMR0;
-\newline
+\begin_layout List
+\labelwidthstring 00.00.0000
-\newline
-__sbit __at
-\begin_inset LatexCommand \index{at}
+\series bold
+-
+\begin_inset ERT
+status collapsed
-\end_inset
+\begin_layout Standard
-\begin_inset LatexCommand \index{\_\_at}
+\backslash
+/
+\end_layout
\end_inset
- (0xd7) CY;\InsetSpace ~
- /* CY (Carry Flag
-\begin_inset LatexCommand \index{Flags}
+-dumploop
+\begin_inset LatexCommand \index{-\/-dumploop}
\end_inset
-\begin_inset LatexCommand \index{Carry flag}
+\series default
+\size large
-\end_inset
+\size default
+Will create a dump of iCodes, after loop optimizations
+\begin_inset LatexCommand \index{Loop optimization}
-) */
-\end_layout
+\end_inset
-\begin_layout Standard
-Special function registers which are located on an address dividable by
- 8 are bit-addressable, an
-\emph on
- sbit
-\emph default
- addresses a specific bit within these sfr.
-\newline
-16 Bit and 32 bit special function
- register combinations which require a certain access order are better not
- declared using
-\emph on
-sfr16
-\emph default
- or
+, into a file named
\emph on
-sfr32.
-
-\emph default
- Allthough SDCC usually accesses them Least Significant Byte (LSB) first,
- this is not guaranteed.
-\newline
-
+<source filename>.dumploop.
\end_layout
-\begin_layout Standard
-Please note, if you use a header file which was written for another compiler
- then the sfr / sfr16 / sfr32 / sbit Storage Class extensions will most
- likely be
-\emph on
-not
-\emph default
-compatible.
- Specifically the syntax
-\family typewriter
-\InsetSpace ~
-sfr P0 = 0x80;\InsetSpace ~
-
-\family default
- is compiled
-\emph on
-without warning
-\emph default
- by SDCC to an assignment of 0x80 to a variable called P0
-\family typewriter
+\begin_layout List
+\labelwidthstring 00.00.0000
-\begin_inset Marginal
+\series bold
+-
+\begin_inset ERT
status collapsed
\begin_layout Standard
-\series bold
-\InsetSpace ~
-!
+
+\backslash
+/
\end_layout
\end_inset
-.
-
-\family default
-Nevertheless it is possible to write header files
-\begin_inset LatexCommand \index{Header files}
+-dumprange
+\begin_inset LatexCommand \index{-\/-dumprange}
\end_inset
-\begin_inset LatexCommand \index{Include files}
-
-\end_inset
+\series default
+\size large
- which can be shared among different compilers (see section
-\begin_inset LatexCommand \ref{sec:Porting-code-to-other-compilers}
+\size default
+Will create a dump of iCodes, after live range analysis
+\begin_inset LatexCommand \index{Live range analysis}
\end_inset
-).
-
+, into a file named
+\emph on
+<source filename>.dumprange.
\end_layout
-\begin_layout Subsubsection
-Pointers
-\begin_inset LatexCommand \index{Pointer}
-
-\end_inset
+\begin_layout List
+\labelwidthstring 00.00.0000
- to MCS51/DS390 specific memory spaces
-\end_layout
+\series bold
+-
+\begin_inset ERT
+status collapsed
\begin_layout Standard
-SDCC allows (via language extensions) pointers to explicitly point to any
- of the memory spaces
-\begin_inset LatexCommand \index{Memory model}
-\end_inset
-
- of the 8051.
- In addition to the explicit pointers, the compiler uses (by default) generic
- pointers which can be used to point to any of the memory spaces.
-\newline
-\newline
-Pointer
- declaration examples:
+\backslash
+/
\end_layout
-\begin_layout Verse
-
-\family typewriter
-/* pointer physically in internal ram pointing to object in external ram
- */
-\newline
-__xdata unsigned char * __data p;
-\newline
-
-\newline
-/* pointer physically in external ram
- pointing to object in internal ram */
-\newline
-__data unsigned char * __xdata p;
-\newline
-
-\newline
-/*
- pointer physically in code rom pointing to data in xdata space */
-\newline
-__xdata
- unsigned char * __code p;
-\newline
+\end_inset
-\newline
-/* pointer physically in code space pointing to
- data in code space */
-\newline
-__code unsigned char * __code p;
-\newline
+-dumlrange
+\begin_inset LatexCommand \index{-\/-dumlrange}
-\newline
-/* generic pointer
- physically located in xdata space */
-\newline
-unsigned char * __xdata p;
-\newline
+\end_inset
-\newline
-/* generic
- pointer physically located in default memory space */
-\newline
-unsigned char * p;
-\newline
-\newline
-/*
- the following is a function pointer
-\begin_inset LatexCommand \index{function pointer}
+\series default
+ Will dump the life ranges
+\begin_inset LatexCommand \index{Live range analysis}
\end_inset
- physically located in data space */
-\newline
-char (* __data fp)(void);
+ for all symbols.
\end_layout
-\begin_layout Standard
-Well you get the idea.
-
-\newline
+\begin_layout List
+\labelwidthstring 00.00.0000
-\newline
-All unqualified pointers are treated as 3-byte (4-byte for the ds390)
-\emph on
-generic
-\emph default
- pointers.
-
-\size small
+\series bold
+-
+\begin_inset ERT
+status collapsed
-\newline
+\begin_layout Standard
-\newline
-\size default
-The highest order byte of the
-\emph on
-generic
-\emph default
- pointers contains the data space information.
- Assembler support routines are called whenever data is stored or retrieved
- using
-\emph on
-generic
-\emph default
- pointers.
- These are useful for developing reusable library
-\begin_inset LatexCommand \index{Libraries}
+\backslash
+/
+\end_layout
\end_inset
- routines.
- Explicitly specifying the pointer
-\begin_inset LatexCommand \index{pointer}
+-dumpregassign
+\begin_inset LatexCommand \index{-\/-dumpregassign}
\end_inset
- type will generate the most efficient code.
-\end_layout
-\begin_layout Subsubsection
-Notes on MCS51 memory
-\begin_inset LatexCommand \index{MCS51 memory}
+\bar under
+
+\series default
+\bar default
+Will create a dump of iCodes, after register assignment
+\begin_inset LatexCommand \index{Register assignment}
\end_inset
- layout
+, into a file named
+\emph on
+<source filename>.dumprassgn.
\end_layout
-\begin_layout Standard
-The 8051 family of microcontrollers have a minimum of 128 bytes of internal
- RAM memory which is structured as follows:
-\newline
+\begin_layout List
+\labelwidthstring 00.00.0000
-\newline
-- Bytes 00-1F - 32 bytes to hold
- up to 4 banks of the registers R0 to R7,
-\newline
-- Bytes 20-2F - 16 bytes to hold
- 128 bit
-\begin_inset LatexCommand \index{bit}
+\series bold
+-
+\begin_inset ERT
+status collapsed
-\end_inset
+\begin_layout Standard
- variables and,
-\newline
-- Bytes 30-7F - 80 bytes for general purpose use.
-\newline
+\backslash
+/
\end_layout
-\begin_layout Standard
-Additionally some members of the MCS51 family may have up to 128 bytes of
- additional, indirectly addressable, internal RAM memory (
-\emph on
-idata
-\emph default
-
-\begin_inset LatexCommand \index{idata (mcs51, ds390 storage class)}
-
\end_inset
-
-\begin_inset LatexCommand \index{\_\_idata (mcs51, ds390 storage class)}
+-dumplrange
+\begin_inset LatexCommand \index{-\/-dumplrange}
\end_inset
-).
- Furthermore, some chips may have some built in external memory (
-\emph on
-xdata
-\emph default
-
-\begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
-\end_inset
+\series default
+ Will create a dump of the live ranges of iTemp's
+\end_layout
+\begin_layout List
+\labelwidthstring 00.00.0000
-\begin_inset LatexCommand \index{\_\_xdata (mcs51, ds390 storage class)}
+\series bold
+-
+\begin_inset ERT
+status collapsed
-\end_inset
+\begin_layout Standard
-) which should not be confused with the internal, directly addressable RAM
- memory (
-\emph on
-data
-\emph default
-\begin_inset LatexCommand \index{data (mcs51, ds390 storage class)}
+\backslash
+/
+\end_layout
\end_inset
-
-\begin_inset LatexCommand \index{\_\_data (mcs51, ds390 storage class)}
+-dumpall
+\begin_inset LatexCommand \index{-\/-dumpall}
\end_inset
-).
- Sometimes this built in
-\emph on
-xdata
-\emph default
- memory has to be activated before using it (you can probably find this
- information on the datasheet of the microcontroller your are using, see
- also section
-\begin_inset LatexCommand \ref{sub:Startup-Code}
-\end_inset
+\size large
+\bar under
-\InsetSpace ~
-Startup-Code).
+\series default
+\size default
+\bar default
+Will cause all the above mentioned dumps to be created.
\end_layout
\begin_layout Standard
-Normally SDCC will only use the first bank
-\begin_inset LatexCommand \index{register bank (mcs51, ds390)}
-
+\begin_inset VSpace bigskip
\end_inset
- of registers (register bank 0), but it is possible to specify that other
- banks of registers (keyword
-\emph on
-using
-\emph default
-
-\emph on
-
-\begin_inset LatexCommand \index{using (mcs51, ds390 register bank)}
-
-\end_inset
+\end_layout
-\begin_inset LatexCommand \index{\_\_using (mcs51, ds390 register bank)}
+\begin_layout Subsection
+Redirecting output on Windows Shells
+\end_layout
+\begin_layout Standard
+By default SDCC writes its error messages to
+\begin_inset Quotes sld
\end_inset
-
-\emph default
-) should be used in interrupt
-\begin_inset LatexCommand \index{interrupt}
-
+standard error
+\begin_inset Quotes srd
\end_inset
-
-\begin_inset LatexCommand \index{\_\_interrupt}
-
+.
+ To force all messages to
+\begin_inset Quotes sld
\end_inset
- routines.
- By default, the compiler will place the stack after the last byte of allocated
- memory for variables.
- For example, if the first 2 banks of registers are used, and only four
- bytes are used for
-\emph on
-data
-\emph default
- variables, it will position the base of the internal stack at address 20
- (0x14).
- This implies that as the stack
-\begin_inset LatexCommand \index{stack}
-
+standard output
+\begin_inset Quotes srd
\end_inset
- grows, it will use up the remaining register banks, and the 16 bytes used
- by the 128 bit variables, and 80 bytes for general purpose use.
- If any bit variables are used, the data variables will be placed in unused
- register banks and after the byte holding the last bit variable.
- For example, if register banks 0 and 1 are used, and there are 9 bit variables
- (two bytes used),
+ use
+\series bold
+-
+\series default
\emph on
-data
-\emph default
- variables will be placed starting from address 0x10 to 0x20 and continue
- at address 0x22.
- You can also use -
+
\begin_inset ERT
status collapsed
\end_inset
--data-loc
-\begin_inset LatexCommand \index{-\/-data-loc <Value>}
+
+\series bold
+\emph default
+-
+\series default
+use-stdout
+\begin_inset LatexCommand \index{-\/-use-stdout}
\end_inset
- to specify the start address of the
+.
+ Additionally, if you happen to have visual studio installed in your windows
+ machine, you can use it to compile your sources using a custom build and
+ the SDCC -
\emph on
-data
-\emph default
- and -
+
\begin_inset ERT
status collapsed
\end_inset
--iram-size
-\begin_inset LatexCommand \index{-\/-iram-size <Value>}
+
+\emph default
+-vc
+\begin_inset LatexCommand \index{-\/-vc}
\end_inset
- to specify the size of the total internal RAM (
-\emph on
-data
-\emph default
-+
-\emph on
-idata
-\emph default
-).
-
+ option.
+ Something like this should work:
\newline
-\end_layout
+\newline
+
+\series bold
+c:
+\backslash
+sdcc
+\backslash
+bin
+\backslash
+sdcc.exe -
+\series default
+\emph on
-\begin_layout Standard
-By default the 8051 linker will place the stack after the last byte of (i)data
- variables.
- Option -
\begin_inset ERT
status collapsed
\end_inset
--stack-loc
-\begin_inset LatexCommand \index{-\/-stack-loc <Value>}
-
-\end_inset
- allows you to specify the start of the stack, i.e.
- you could start it after any data in the general purpose area.
- If your microcontroller has additional indirectly addressable internal
- RAM (
-\emph on
-idata
+\series bold
\emph default
-) you can place the stack on it.
- You may also need to use -
+-vc -
+\series default
+\emph on
+
\begin_inset ERT
status collapsed
\end_inset
--xdata-loc
-\begin_inset LatexCommand \index{-\/-xdata-loc<Value>}
+\series bold
+\emph default
+-model-large -c $(InputPath)
+\series default
+
+\begin_inset VSpace bigskip
\end_inset
- to set the start address of the external RAM (
-\emph on
-xdata
-\emph default
-) and -
-\begin_inset ERT
-status collapsed
-\begin_layout Standard
+\end_layout
+\begin_layout Section
+Environment variables
+\begin_inset LatexCommand \index{Environment variables}
-\backslash
-/
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+SDCC recognizes the following environment variables:
\end_layout
+\begin_layout List
+\labelwidthstring 00.00.0000
+
+\series bold
+SDCC_LEAVE_SIGNALS
+\begin_inset LatexCommand \index{SDCC\_LEAVE\_SIGNALS}
+
\end_inset
--xram-size
-\begin_inset LatexCommand \index{-\/-xram-size <Value>}
+
+\series default
+ SDCC installs a signal handler
+\begin_inset LatexCommand \index{signal handler}
\end_inset
- to specify its size.
- Same goes for the code memory, using -
-\begin_inset ERT
-status collapsed
+ to be able to delete temporary files after an user break (^C) or an exception.
+ If this environment variable is set, SDCC won't install the signal handler
+ in order to be able to debug SDCC.
+\end_layout
-\begin_layout Standard
+\begin_layout List
+\labelwidthstring 00.00.0000
+
+\series bold
+TMP,\InsetSpace ~
+TEMP,\InsetSpace ~
+TMPDIR
+\begin_inset LatexCommand \index{TMP, TEMP, TMPDIR}
+\end_inset
-\backslash
-/
+
+\series default
+ Path, where temporary files will be created.
+ The order of the variables is the search order.
+ In a standard *nix environment these variables are not set, and there's
+ no need to set them.
+ On Windows it's recommended to set one of them.
\end_layout
+\begin_layout List
+\labelwidthstring 00.00.0000
+
+\series bold
+SDCC_HOME
+\begin_inset LatexCommand \index{SDCC\_HOME}
+
\end_inset
--code-loc
-\begin_inset LatexCommand \index{-\/-code-loc <Value>}
+
+\series default
+ Path, see section
+\begin_inset LatexCommand \ref{sub:Install-paths}
\end_inset
- and -
-\begin_inset ERT
-status collapsed
+\InsetSpace ~
-\begin_layout Standard
+\begin_inset Quotes sld
+\end_inset
+ Install Paths
+\begin_inset Quotes srd
+\end_inset
-\backslash
-/
+.
\end_layout
+\begin_layout List
+\labelwidthstring 00.00.0000
+
+\series bold
+SDCC_INCLUDE
+\begin_inset LatexCommand \index{SDCC\_INCLUDE}
+
\end_inset
--code-size
-\begin_inset LatexCommand \index{-\/-code-size <Value>}
+\series default
+ Path, see section
+\begin_inset LatexCommand \ref{sub:Search-Paths}
+
+\end_inset
+
+\InsetSpace ~
+
+\begin_inset Quotes sld
+\end_inset
+
+Search Paths
+\begin_inset Quotes srd
\end_inset
.
- If in doubt, don't specify any options and see if the resulting memory
- layout is appropriate, then you can adjust it.
\end_layout
-\begin_layout Standard
-The linker generates two files with memory allocation information.
- The first, with extension .map
-\begin_inset LatexCommand \index{<file>.map}
+\begin_layout List
+\labelwidthstring 00.00.0000
+
+\series bold
+SDCC_LIB
+\begin_inset LatexCommand \index{SDCC\_LIB}
\end_inset
- shows all the variables and segments.
- The second with extension .mem
-\begin_inset LatexCommand \index{<file>.mem}
+
+\series default
+ Path, see section
+\begin_inset LatexCommand \ref{sub:Search-Paths}
\end_inset
- shows the final memory layout.
- The linker will complain either if memory segments overlap, there is not
- enough memory, or there is not enough space for stack.
- If you get any linking warnings and/or errors related to stack or segments
- allocation, take a look at either the .map or .mem files to find out what
- the problem is.
- The .mem file may even suggest a solution to the problem.
+\InsetSpace ~
+
+\begin_inset Quotes sld
+\end_inset
+
+Search Paths
+\begin_inset Quotes srd
+\end_inset
+
+..
+\end_layout
+
+\begin_layout Standard
+There are some more environment variables recognized by SDCC, but these
+ are solely used for debugging purposes.
+ They can change or disappear very quickly, and will never be documented.
\begin_inset VSpace bigskip
\end_inset
\end_layout
+\begin_layout Section
+Storage Class Language Extensions
+\end_layout
+
\begin_layout Subsection
-Z80/Z180 Storage Class
-\begin_inset LatexCommand \index{Z80!Storage class}
+MCS51/DS390 Storage Class
+\begin_inset LatexCommand \index{Storage class}
\end_inset
Language Extensions
\end_layout
+\begin_layout Standard
+In addition to the ANSI storage classes SDCC allows the following MCS51
+ specific storage classes:
+\end_layout
+
\begin_layout Subsubsection
-sfr
-\begin_inset LatexCommand \index{sfr}
+data
+\begin_inset LatexCommand \index{data (mcs51, ds390 storage class)}
\end_inset
-\begin_inset LatexCommand \index{\_\_sfr}
+\begin_inset LatexCommand \index{\_\_data (mcs51, ds390 storage class)}
\end_inset
- (in/out to 8-bit addresses)
-\end_layout
+ / near
+\begin_inset LatexCommand \index{near (storage class)}
-\begin_layout Standard
-The Z80
-\begin_inset LatexCommand \index{Z80}
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_near (storage class)}
\end_inset
- family has separate address spaces for memory and
+
+\end_layout
+
+\begin_layout Standard
+This is the
+\series bold
+default
+\series default
+ storage class for the Small Memory model (
\emph on
-i
+data
\emph default
-nput/
+ and
\emph on
-o
+near
\emph default
-utput memory.
- I/O memory
-\begin_inset LatexCommand \index{I/O memory (Z80, Z180)}
+ or the more ANSI-C compliant forms
+\emph on
+__data
+\emph default
+ and
+\emph on
+__near
+\emph default
+ can be used synonymously).
+ Variables declared with this storage class will be allocated in the directly
+ addressable portion of the internal RAM of a 8051, e.g.:
+\end_layout
+
+\begin_layout Verse
+
+\family typewriter
+__data unsigned char test_data;
+\end_layout
+
+\begin_layout Standard
+Writing 0x01 to this variable generates the assembly code:
+\end_layout
+
+\begin_layout Verse
+
+\family typewriter
+75*00 01\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+mov\InsetSpace ~
+\InsetSpace ~
+_test_data,#0x01
+\end_layout
+
+\begin_layout Subsubsection
+xdata
+\begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
\end_inset
-\begin_inset LatexCommand \index{Z80!I/O memory}
+\begin_inset LatexCommand \index{\_\_xdata (mcs51, ds390 storage class)}
\end_inset
+ / far
+\begin_inset LatexCommand \index{far (storage class)}
-\begin_inset LatexCommand \index{Z180!I/O memory}
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_far (storage class)}
\end_inset
- is accessed with special instructions, e.g.:
+
+\end_layout
+
+\begin_layout Standard
+Variables declared with this storage class will be placed in the external
+ RAM.
+ This is the
+\series bold
+default
+\series default
+ storage class for the Large Memory model, e.g.:
\end_layout
\begin_layout Verse
\family typewriter
-sfr at 0x78 IoPort;\InsetSpace ~
-\InsetSpace ~
-/* define a var in I/O space at 78h called IoPort */
-
+__xdata unsigned char test_xdata;
\end_layout
\begin_layout Standard
\begin_layout Verse
\family typewriter
-3E 01\InsetSpace ~
+90s00r00\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+mov\InsetSpace ~
\InsetSpace ~
+dptr,#_test_xdata
+\newline
+74\InsetSpace ~
+01\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-ld a,#0x01
+\InsetSpace ~
+mov\InsetSpace ~
+\InsetSpace ~
+a,#0x01
\newline
-D3 78\InsetSpace ~
+F0\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-out (_IoPort),a
+movx\InsetSpace ~
+@dptr,a
\end_layout
\begin_layout Subsubsection
-banked sfr
-\begin_inset LatexCommand \index{sfr}
+idata
+\begin_inset LatexCommand \index{idata (mcs51, ds390 storage class)}
\end_inset
-\begin_inset LatexCommand \index{\_\_sfr}
+\begin_inset LatexCommand \index{\_\_idata (mcs51, ds390 storage class)}
\end_inset
- (in/out to 16-bit addresses)
+
\end_layout
\begin_layout Standard
-The keyword
-\emph on
-banked
-\emph default
- is used to support 16 bit addresses in I/O memory e.g.:
+Variables declared with this storage class will be allocated into the indirectly
+ addressable portion of the internal ram of a 8051, e.g.:
\end_layout
\begin_layout Verse
\family typewriter
-sfr banked at
-\begin_inset LatexCommand \index{at}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{\_\_at}
-
-\end_inset
-
- 0x123 IoPort;
+__idata unsigned char test_idata;
\end_layout
\begin_layout Standard
\begin_layout Verse
\family typewriter
-01 23 01\InsetSpace ~
+78r00\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-ld bc,#_IoPort
-\newline
-3E 01\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
+mov\InsetSpace ~
\InsetSpace ~
-ld a,#0x01
+r0,#_test_idata
\newline
-ED 79\InsetSpace ~
+76\InsetSpace ~
+01\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-out (c),a
+\InsetSpace ~
+mov\InsetSpace ~
+\InsetSpace ~
+@r0,#0x01
\end_layout
-\begin_layout Subsubsection
-sfr
-\begin_inset LatexCommand \index{sfr}
+\begin_layout Standard
+Please note, the first 128 byte of idata physically access the same RAM
+ as the data memory.
+ The original 8051 had 128 byte idata memory, nowadays most devices have
+ 256 byte idata memory.
+ The stack
+\begin_inset LatexCommand \index{stack}
\end_inset
+ is located in idata memory.
+\end_layout
-\begin_inset LatexCommand \index{\_\_sfr}
+\begin_layout Subsubsection
+pdata
+\begin_inset LatexCommand \index{pdata (mcs51, ds390 storage class)}
\end_inset
- (in0/out0 to 8 bit addresses on Z180
-\begin_inset LatexCommand \index{Z180}
-
-\end_inset
-/HD64180
-\begin_inset LatexCommand \index{HD64180 (see Z180)}
+\begin_inset LatexCommand \index{\_\_pdata (mcs51, ds390 storage class)}
\end_inset
-)
-\end_layout
-\begin_layout Standard
-The compiler option -
-\begin_inset ERT
-status collapsed
+\end_layout
\begin_layout Standard
-
-
-\backslash
-/
-\end_layout
+Paged xdata access is just as straightforward as using the other addressing
+ modes of a 8051.
+ It is typically located at the start of xdata and has a maximum size of
+ 256 bytes.
+ The following example writes 0x01 to the pdata variable.
+ Please note, pdata access physically accesses xdata memory.
+ The high byte of the address is determined by port P2
+\begin_inset LatexCommand \index{P2 (mcs51 sfr)}
\end_inset
--portmode
-\begin_inset LatexCommand \index{Z180!Options!-\/-portmode}
+(or in case of some 8051 variants by a separate Special Function Register,
+ see section
+\begin_inset LatexCommand \ref{sub:MCS51-variants}
\end_inset
-=180 (80) and a compiler #pragma\InsetSpace ~
-portmode
-\begin_inset LatexCommand \index{Z180!Pragmas!\#pragma portmode}
+).
+ This is the
+\series bold
+default
+\series default
+ storage class for the Medium Memory model, e.g.:
+\end_layout
-\end_inset
+\begin_layout Verse
- z180 (z80) is used to turn on (off) the Z180/HD64180 port addressing instructio
-ns
-\family typewriter
-in0/out0
-\family default
- instead of
\family typewriter
-in/out
-\family default
-.
- If you include the file z180.h this will be set automatically.
-\begin_inset VSpace bigskip
-\end_inset
-
-
+__pdata unsigned char test_pdata;
\end_layout
-\begin_layout Subsection
-HC08 Storage Class
-\begin_inset LatexCommand \index{HC08!Storage class}
+\begin_layout Standard
+Writing 0x01 to this variable generates the assembly code:
+\end_layout
-\end_inset
+\begin_layout Verse
- Language Extensions
+\family typewriter
+78r00\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+mov r0,#_test_pdata
+\newline
+74 01\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+mov a,#0x01
+\newline
+F2\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+movx @r0,a
\end_layout
-\begin_layout Subsubsection
-data
-\begin_inset LatexCommand \index{data (hc08 storage class)}
+\begin_layout Standard
+If the -
+\begin_inset ERT
+status collapsed
-\end_inset
+\begin_layout Standard
-\begin_inset LatexCommand \index{\_\_data (hc08 storage class)}
+\backslash
+/
+\end_layout
\end_inset
-
-\end_layout
-
-\begin_layout Standard
-The data storage class declares a variable that resides in the first 256
- bytes of memory (the direct page).
- The HC08
-\begin_inset LatexCommand \index{HC08}
+-xstack
+\begin_inset LatexCommand \index{-\/-xstack}
\end_inset
- is most efficient at accessing variables (especially pointers) stored here.
+ option is used the pdata memory area is followed by the xstack memory area
+ and the sum of their sizes is limited to 256 bytes.
\end_layout
\begin_layout Subsubsection
-xdata
-\begin_inset LatexCommand \index{xdata (hc08 storage class)}
+code
+\begin_inset LatexCommand \index{code}
\end_inset
-\begin_inset LatexCommand \index{\_\_xdata (hc08 storage class)}
+\begin_inset LatexCommand \index{\_\_code}
\end_inset
-
+
\end_layout
\begin_layout Standard
-The xdata storage class declares a variable that can reside anywhere in
- memory.
- This is the default if no storage class is specified.
-
-\begin_inset VSpace bigskip
-\end_inset
-
-
+'Variables' declared with this storage class will be placed in the code
+ memory:
\end_layout
-\begin_layout Section
-Absolute Addressing
-\begin_inset LatexCommand \index{Absolute addressing}
+\begin_layout Verse
-\end_inset
+\family typewriter
+__code unsigned char test_code;
+\end_layout
+
+\begin_layout Standard
+Read access to this variable generates the assembly code:
+\end_layout
+\begin_layout Verse
+\family typewriter
+90s00r6F\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+mov dptr,#_test_code
+\newline
+E4\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+clr a
+\newline
+93\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+movc a,@a+dptr
\end_layout
\begin_layout Standard
-Data items can be assigned an absolute address with the
-\emph on
-at
-\begin_inset LatexCommand \index{at}
-\end_inset
+\family typewriter
+char
+\family default
+ indexed arrays of characters in code memory can be accessed efficiently:
+\end_layout
+\begin_layout Verse
-\begin_inset LatexCommand \index{\_\_at}
+\family typewriter
+__code char test_array[] = {'c','h','e','a','p'};
+\end_layout
-\end_inset
+\begin_layout Standard
+Read access to this array using an 8-bit unsigned index generates the assembly
+ code:
+\end_layout
- <address>
-\emph default
- keyword, in addition to a storage class, e.g.:
+\begin_layout Verse
+
+\family typewriter
+E5*00\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+mov a,_index
\end_layout
\begin_layout Verse
\family typewriter
-xdata
-\begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
+90s00r41\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+mov dptr,#_test_array
+\end_layout
-\end_inset
+\begin_layout Verse
+\family typewriter
+93\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+movc a,@a+dptr
+\end_layout
-\begin_inset LatexCommand \index{\_\_xdata (mcs51, ds390 storage class)}
+\begin_layout Subsubsection
+bit
+\begin_inset LatexCommand \index{bit}
\end_inset
- at
-\begin_inset LatexCommand \index{at}
+
+\begin_inset LatexCommand \index{\_\_bit}
\end_inset
-\begin_inset LatexCommand \index{\_\_at}
+\end_layout
-\end_inset
+\begin_layout Standard
+This is a data-type and a storage class specifier.
+ When a variable is declared as a bit, it is allocated into the bit addressable
+ memory of 8051, e.g.:
+\end_layout
- 0x7ffe unsigned int chksum;
+\begin_layout Verse
+
+\family typewriter
+__bit test_bit;
\end_layout
\begin_layout Standard
-or, better conforming to ISO/IEC 9899 C:
+Writing 1 to this variable generates the assembly code:
\end_layout
\begin_layout Verse
\family typewriter
-__xdata __at (0x7ffe) unsigned int chksum;
+D2*00\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+setb\InsetSpace ~
+_test_bit
\end_layout
\begin_layout Standard
-In the above example the variable chksum will be located at 0x7ffe and 0x7fff
- of the external ram.
- The compiler does
-\emph on
-not
-\emph default
- reserve any space for variables declared in this way
-\begin_inset Marginal
-status collapsed
+The bit addressable memory consists of 128 bits which are located from 0x20
+ to 0x2f in data memory.
+
+\newline
+Apart from this 8051 specific storage class most architectures support
+ ANSI-C bitfields
+\begin_inset LatexCommand \index{bitfields}
+
+\end_inset
+
+
+\begin_inset Foot
+status open
\begin_layout Standard
+Not really meant as examples, but nevertheless showing what bitfields are
+ about: device/include/mc68hc908qy.h and support/regression/tests/bitfields.c
+\end_layout
-\series bold
-\InsetSpace ~
-!
+\end_inset
+
+.
+ In accordance with ISO/IEC 9899 bits and bitfields without an explicit
+ signed modifier are implemented as unsigned.
\end_layout
+\begin_layout Subsubsection
+sfr
+\begin_inset LatexCommand \index{sfr}
+
\end_inset
- (they are implemented with an equate in the assembler).
- Thus it is left to the programmer to make sure there are no overlaps with
- other variables that are declared without the absolute address.
- The assembler listing file (.lst
-\begin_inset LatexCommand \index{<file>.lst}
+
+\begin_inset LatexCommand \index{\_\_sfr}
\end_inset
-) and the linker output files (.rst
-\begin_inset LatexCommand \index{<file>.rst}
+ / sfr16
+\begin_inset LatexCommand \index{sfr16}
\end_inset
-) and (.map
-\begin_inset LatexCommand \index{<file>.map}
+
+\begin_inset LatexCommand \index{\_\_sfr16}
\end_inset
-) are good places to look for such overlaps.
- Variables with an absolute address are
-\emph on
-not
-\begin_inset Marginal
-status collapsed
+ / sfr32
+\begin_inset LatexCommand \index{sfr32}
-\begin_layout Standard
+\end_inset
-\series bold
-\InsetSpace ~
-!
-\end_layout
+
+\begin_inset LatexCommand \index{\_\_sfr32}
+
+\end_inset
+
+ / sbit
+\begin_inset LatexCommand \index{\_\_sbit}
\end_inset
-\emph default
- initialized
-\begin_inset LatexCommand \index{Variable initialization}
+\begin_inset LatexCommand \index{sbit}
\end_inset
-.
+
\end_layout
\begin_layout Standard
-In case of memory mapped I/O devices the keyword
+Like the bit keyword,
\emph on
-volatile
+sfr / sfr16 / sfr32 / sbit
\emph default
- has to be used to tell the compiler that accesses might not be removed:
+signify both a data-type and storage class, they are used to describe the
+
+\emph on
+s
+\emph default
+pecial
+\emph on
+f
+\emph default
+unction
+\emph on
+r
+\emph default
+egisters and
+\emph on
+s
+\emph default
+pecial
+\emph on
+bit
+\emph default
+ variables of a 8051, eg:
\end_layout
\begin_layout Verse
\family typewriter
-volatile
-\begin_inset LatexCommand \index{volatile}
+__sfr __at
+\begin_inset LatexCommand \index{at}
\end_inset
- __xdata
-\begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
+
+\begin_inset LatexCommand \index{\_\_at}
\end_inset
- __at
+ (0x80) P0;\InsetSpace ~
+ /* special function register P0 at location 0x80 */
+\newline
+
+\newline
+/* 16 bit
+ special function register combination for timer 0
+\newline
+\InsetSpace ~
+\InsetSpace ~
+ with the high byte at
+ location 0x8C and the low byte at location 0x8A */
+\newline
+__sfr16 __at (0x8C8A)
+ TMR0;
+\newline
+
+\newline
+__sbit __at
\begin_inset LatexCommand \index{at}
\end_inset
- (0x8000) unsigned char PORTA_8255;
+
+\begin_inset LatexCommand \index{\_\_at}
+
+\end_inset
+
+ (0xd7) CY;\InsetSpace ~
+ /* CY (Carry Flag
+\begin_inset LatexCommand \index{Flags}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Carry flag}
+
+\end_inset
+
+) */
\end_layout
\begin_layout Standard
-For some architectures (mcs51) array accesses are more efficient if an (xdata/fa
-r) array
+Special function registers which are located on an address dividable by
+ 8 are bit-addressable, an
+\emph on
+ sbit
+\emph default
+ addresses a specific bit within these sfr.
+\newline
+16 Bit and 32 bit special function
+ register combinations which require a certain access order are better not
+ declared using
+\emph on
+sfr16
+\emph default
+ or
+\emph on
+sfr32.
+
+\emph default
+ Allthough SDCC usually accesses them Least Significant Byte (LSB) first,
+ this is not guaranteed.
+\newline
+
+\end_layout
+
+\begin_layout Standard
+Please note, if you use a header file which was written for another compiler
+ then the sfr / sfr16 / sfr32 / sbit Storage Class extensions will most
+ likely be
+\emph on
+not
+\emph default
+compatible.
+ Specifically the syntax
\family typewriter
-\size footnotesize
+\InsetSpace ~
+sfr P0 = 0x80;\InsetSpace ~
-\begin_inset LatexCommand \index{Aligned array}
+\family default
+ is compiled
+\emph on
+without warning
+\emph default
+ by SDCC to an assignment of 0x80 to a variable called P0
+\family typewriter
+
+\begin_inset Marginal
+status collapsed
+
+\begin_layout Standard
+
+\series bold
+\InsetSpace ~
+!
+\end_layout
\end_inset
+.
\family default
-\size default
- starts at a block (256 byte) boundary
-\begin_inset LatexCommand \index{block boundary}
+Nevertheless it is possible to write header files
+\begin_inset LatexCommand \index{Header files}
\end_inset
- (section
-\begin_inset LatexCommand \ref{sub:A-Step-by Assembler Introduction}
+
+\begin_inset LatexCommand \index{Include files}
\end_inset
- has an example).
-\newline
-Absolute addresses can be specified for variables in all
- storage classes, e.g.:
-\end_layout
+ which can be shared among different compilers (see section
+\begin_inset LatexCommand \ref{sec:Porting-code-to-other-compilers}
-\begin_layout Verse
+\end_inset
-\family typewriter
-__bit
-\begin_inset LatexCommand \index{bit}
+).
-\end_inset
+\end_layout
- __at
-\begin_inset LatexCommand \index{at}
+\begin_layout Subsubsection
+Pointers
+\begin_inset LatexCommand \index{Pointer}
\end_inset
- (0x02) bvar;
+ to MCS51/DS390 specific memory spaces
\end_layout
\begin_layout Standard
-The above example will allocate the variable at offset 0x02 in the bit-addressab
-le space.
- There is no real advantage to assigning absolute addresses to variables
- in this manner, unless you want strict control over all the variables allocated.
- One possible use would be to write hardware portable code.
- For example, if you have a routine that uses one or more of the microcontroller
- I/O pins, and such pins are different for two different hardwares, you
- can declare the I/O pins in your routine using:
+SDCC allows (via language extensions) pointers to explicitly point to any
+ of the memory spaces
+\begin_inset LatexCommand \index{Memory model}
+
+\end_inset
+
+ of the 8051.
+ In addition to the explicit pointers, the compiler uses (by default) generic
+ pointers which can be used to point to any of the memory spaces.
+\newline
+
+\newline
+Pointer
+ declaration examples:
\end_layout
\begin_layout Verse
\family typewriter
-extern volatile
-\begin_inset LatexCommand \index{volatile}
-
-\end_inset
-
- __bit MOSI;\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-/* master out, slave in */
-\newline
-extern volatile __bit MISO;\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-/* master
- in, slave out */
+/* pointer physically in internal ram pointing to object in external ram
+ */
\newline
-extern volatile __bit MCLK;\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-/* master clock */
+__xdata unsigned char * __data p;
\newline
\newline
-/* Input and
- Output of a byte on a 3-wire serial bus.
+/* pointer physically in external ram
+ pointing to object in internal ram */
\newline
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-If needed adapt polarity of clock,
- polarity of data and bit order
+__data unsigned char * __xdata p;
\newline
-\InsetSpace ~
-*/
+
\newline
-unsigned char spi_io(unsigned char out_byte)
-
+/*
+ pointer physically in code rom pointing to data in xdata space */
\newline
-{
+__xdata
+ unsigned char * __code p;
\newline
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-unsigned char i=8;
+
\newline
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-do {
+/* pointer physically in code space pointing to
+ data in code space */
\newline
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-MOSI = out_byte & 0x80;
+__code unsigned char * __code p;
\newline
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-out_byte <<= 1;
+
\newline
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-MCLK =
- 1;
+/* generic pointer
+ physically located in xdata space */
\newline
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-/* _asm nop _endasm; */\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-/* for slow peripherals */
+unsigned char * __xdata p;
\newline
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-if(MISO)
+
\newline
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-out_byte +=
- 1;
+/* generic
+ pointer physically located in default memory space */
\newline
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-MCLK = 0;
+unsigned char * p;
\newline
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-} while(--i);
+
\newline
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-return out_byte;
+/*
+ the following is a function pointer
+\begin_inset LatexCommand \index{function pointer}
+
+\end_inset
+
+ physically located in data space */
\newline
-}
+char (* __data fp)(void);
\end_layout
\begin_layout Standard
-Then, someplace in the code for the first hardware you would use
-\end_layout
+Well you get the idea.
-\begin_layout Verse
+\newline
-\family typewriter
-__bit __at
-\begin_inset LatexCommand \index{at}
+\newline
+All unqualified pointers are treated as 3-byte (4-byte for the ds390)
+\emph on
+generic
+\emph default
+ pointers.
-\end_inset
+\size small
+\newline
-\begin_inset LatexCommand \index{\_\_at}
+\newline
+
+\size default
+The highest order byte of the
+\emph on
+generic
+\emph default
+ pointers contains the data space information.
+ Assembler support routines are called whenever data is stored or retrieved
+ using
+\emph on
+generic
+\emph default
+ pointers.
+ These are useful for developing reusable library
+\begin_inset LatexCommand \index{Libraries}
\end_inset
- (0x80) MOSI;\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-/* I/O port 0, bit 0 */
-\newline
-__bit __at (0x81) MISO;\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-/* I/O port 0,
- bit 1 */
-\newline
-__bit __at (0x82) MCLK;\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-/* I/O port 0, bit 2 */
+ routines.
+ Explicitly specifying the pointer
+\begin_inset LatexCommand \index{pointer}
+
+\end_inset
+
+ type will generate the most efficient code.
\end_layout
-\begin_layout Standard
-Similarly, for the second hardware you would use
+\begin_layout Subsubsection
+Notes on MCS51 memory
+\begin_inset LatexCommand \index{MCS51 memory}
+
+\end_inset
+
+ layout
\end_layout
-\begin_layout Verse
+\begin_layout Standard
+The 8051 family of microcontrollers have a minimum of 128 bytes of internal
+ RAM memory which is structured as follows:
+\newline
-\family typewriter
-__bit __at (0x83) MOSI;\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-/* I/O port 0, bit 3 */
\newline
-__bit __at (0x91) MISO;\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-/*
- I/O port 1, bit 1 */
+- Bytes 00-1F - 32 bytes to hold
+ up to 4 banks of the registers R0 to R7,
\newline
-__bit
+- Bytes 20-2F - 16 bytes to hold
+ 128 bit
\begin_inset LatexCommand \index{bit}
\end_inset
- __at (0x92) MCLK;\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-/* I/O port 1, bit 2 */
+ variables and,
+\newline
+- Bytes 30-7F - 80 bytes for general purpose use.
+\newline
+
\end_layout
\begin_layout Standard
-and you can use the same hardware dependent routine without changes, as
- for example in a library.
- This is somehow similar to sbit, but only one absolute address has to be
- specified in the whole project.
-\begin_inset VSpace bigskip
+Additionally some members of the MCS51 family may have up to 128 bytes of
+ additional, indirectly addressable, internal RAM memory (
+\emph on
+idata
+\emph default
+
+\begin_inset LatexCommand \index{idata (mcs51, ds390 storage class)}
+
\end_inset
-\end_layout
+\begin_inset LatexCommand \index{\_\_idata (mcs51, ds390 storage class)}
-\begin_layout Section
-Parameters
-\begin_inset LatexCommand \index{Parameters}
+\end_inset
+
+).
+ Furthermore, some chips may have some built in external memory (
+\emph on
+xdata
+\emph default
+
+\begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
\end_inset
-\begin_inset LatexCommand \index{function parameter}
+\begin_inset LatexCommand \index{\_\_xdata (mcs51, ds390 storage class)}
\end_inset
- & Local Variables
-\begin_inset LatexCommand \index{local variables}
+) which should not be confused with the internal, directly addressable RAM
+ memory (
+\emph on
+data
+\emph default
+
+\begin_inset LatexCommand \index{data (mcs51, ds390 storage class)}
\end_inset
-\begin_inset LatexCommand \label{sec:Parameters-and-Local-Variables}
+\begin_inset LatexCommand \index{\_\_data (mcs51, ds390 storage class)}
\end_inset
+).
+ Sometimes this built in
+\emph on
+xdata
+\emph default
+ memory has to be activated before using it (you can probably find this
+ information on the datasheet of the microcontroller your are using, see
+ also section
+\begin_inset LatexCommand \ref{sub:Startup-Code}
+
+\end_inset
+\InsetSpace ~
+Startup-Code).
\end_layout
\begin_layout Standard
-Automatic (local) variables and parameters to functions can either be placed
- on the stack or in data-space.
- The default action of the compiler is to place these variables in the internal
- RAM (for small model) or external RAM (for large model).
- This in fact makes them similar to
+Normally SDCC will only use the first bank
+\begin_inset LatexCommand \index{register bank (mcs51, ds390)}
+
+\end_inset
+
+ of registers (register bank 0), but it is possible to specify that other
+ banks of registers (keyword
\emph on
-static
-\begin_inset LatexCommand \index{static}
+using
+\emph default
+
+\emph on
+
+\begin_inset LatexCommand \index{using (mcs51, ds390 register bank)}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_using (mcs51, ds390 register bank)}
\end_inset
\emph default
- so by default functions are non-reentrant
-\begin_inset LatexCommand \index{reentrant}
+) should be used for example in interrupt
+\begin_inset LatexCommand \index{interrupt}
\end_inset
-.
-
-\newline
-\newline
-They can be placed on the stack
+\begin_inset LatexCommand \index{\_\_interrupt}
+
+\end_inset
+
+ routines.
+ By default, the compiler will place the stack after the last byte of allocated
+ memory for variables.
+ For example, if the first 2 banks of registers are used, and only four
+ bytes are used for
+\emph on
+data
+\emph default
+ variables, it will position the base of the internal stack at address 20
+ (0x14).
+ This implies that as the stack
\begin_inset LatexCommand \index{stack}
\end_inset
- by using the
+ grows, it will use up the remaining register banks, and the 16 bytes used
+ by the 128 bit variables, and 80 bytes for general purpose use.
+ If any bit variables are used, the data variables will be placed in unused
+ register banks and after the byte holding the last bit variable.
+ For example, if register banks 0 and 1 are used, and there are 9 bit variables
+ (two bytes used),
\emph on
- -
+data
+\emph default
+ variables will be placed starting from address 0x10 to 0x20 and continue
+ at address 0x22.
+ You can also use -
\begin_inset ERT
status collapsed
\end_inset
--stack-auto
-\begin_inset LatexCommand \index{-\/-stack-auto}
+-data-loc
+\begin_inset LatexCommand \index{-\/-data-loc <Value>}
\end_inset
-
-\emph default
- option, by using
+ to specify the start address of the
\emph on
-#pragma\InsetSpace ~
-stackauto
+data
\emph default
+ and -
+\begin_inset ERT
+status collapsed
-\begin_inset LatexCommand \index{\#pragma stackauto}
+\begin_layout Standard
-\end_inset
- or by using the
-\emph on
-reentrant
-\begin_inset LatexCommand \index{reentrant}
+\backslash
+/
+\end_layout
\end_inset
+-iram-size
+\begin_inset LatexCommand \index{-\/-iram-size <Value>}
-\emph default
- keyword in the function declaration, e.g.:
-\end_layout
+\end_inset
-\begin_layout Verse
+ to specify the size of the total internal RAM (
+\emph on
+data
+\emph default
++
+\emph on
+idata
+\emph default
+).
-\family typewriter
-unsigned char foo(char i) __reentrant
\newline
-{
-\newline
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-...
-
-\newline
-}
+
\end_layout
\begin_layout Standard
-Since stack space on 8051 is limited, the
-\emph on
-reentrant
-\emph default
-keyword or the
-\emph on
- -
+By default the 8051 linker will place the stack after the last byte of (i)data
+ variables.
+ Option -
\begin_inset ERT
status collapsed
\end_inset
--stack-auto
-\emph default
- option should be used sparingly.
- Note that the reentrant keyword just means that the parameters & local
- variables will be allocated to the stack, it
-\emph on
-does not
-\emph default
- mean that the function is register bank
-\begin_inset LatexCommand \index{register bank (mcs51, ds390)}
+-stack-loc
+\begin_inset LatexCommand \index{-\/-stack-loc <Value>}
\end_inset
- independent.
-\newline
-
-\newline
-Local variables
-\begin_inset LatexCommand \index{local variables}
-
-\end_inset
+ allows you to specify the start of the stack, i.e.
+ you could start it after any data in the general purpose area.
+ If your microcontroller has additional indirectly addressable internal
+ RAM (
+\emph on
+idata
+\emph default
+) you can place the stack on it.
+ You may also need to use -
+\begin_inset ERT
+status collapsed
- can be assigned storage classes and absolute
-\begin_inset LatexCommand \index{Absolute addressing}
+\begin_layout Standard
-\end_inset
- addresses, e.g.:
+\backslash
+/
\end_layout
-\begin_layout Verse
+\end_inset
-\family typewriter
-unsigned char foo()
-\newline
-{
-\newline
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-__xdata unsigned char i;
-\newline
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-__bit bvar;
-\newline
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-__data __at
-\begin_inset LatexCommand \index{at}
+-xdata-loc
+\begin_inset LatexCommand \index{-\/-xdata-loc<Value>}
\end_inset
- (0x31) unsigned char j;
-\newline
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-...
-
-\newline
-}
-\end_layout
-
-\begin_layout Standard
-In the above example the variable
-\emph on
-i
-\emph default
- will be allocated in the external ram,
-\emph on
-bvar
-\emph default
- in bit addressable space and
+ to set the start address of the external RAM (
\emph on
- j
+xdata
\emph default
- in internal ram.
- When compiled with
-\emph on
--
+) and -
\begin_inset ERT
status collapsed
\end_inset
--stack-auto
-\emph default
- or when a function is declared as
-\emph on
-reentrant
-\emph default
- this should only be done for static variables.
-\end_layout
+-xram-size
+\begin_inset LatexCommand \index{-\/-xram-size <Value>}
+
+\end_inset
+
+ to specify its size.
+ Same goes for the code memory, using -
+\begin_inset ERT
+status collapsed
\begin_layout Standard
-Parameters
-\begin_inset LatexCommand \index{function parameter}
+
+
+\backslash
+/
+\end_layout
\end_inset
- however are not allowed any storage class
-\begin_inset LatexCommand \index{Storage class}
+-code-loc
+\begin_inset LatexCommand \index{-\/-code-loc <Value>}
\end_inset
-, (storage classes for parameters will be ignored), their allocation is
- governed by the memory model in use, and the reentrancy options.
-\end_layout
+ and -
+\begin_inset ERT
+status collapsed
\begin_layout Standard
-It is however allowed to use bit parameters in reentrant functions and also
- non-static local bit variables are supported.
- Efficient use is limited to 8 semi-bitregisters in bit space.
- They are pushed and popped to stack
-\begin_inset LatexCommand \index{stack}
-\end_inset
- as a single byte just like the normal registers.
+\backslash
+/
\end_layout
-\begin_layout Section
-Overlaying
-\begin_inset LatexCommand \label{sub:Overlaying}
-
\end_inset
-
-\begin_inset LatexCommand \index{Overlaying}
+-code-size
+\begin_inset LatexCommand \index{-\/-code-size <Value>}
\end_inset
-
+.
+ If in doubt, don't specify any options and see if the resulting memory
+ layout is appropriate, then you can adjust it.
\end_layout
\begin_layout Standard
-For non-reentrant
-\begin_inset LatexCommand \index{reentrant}
+The linker generates two files with memory allocation information.
+ The first, with extension .map
+\begin_inset LatexCommand \index{<file>.map}
\end_inset
- functions SDCC will try to reduce internal ram space usage by overlaying
- parameters and local variables of a function (if possible).
- Parameters and local variables
-\begin_inset LatexCommand \index{local variables}
+ shows all the variables and segments.
+ The second with extension .mem
+\begin_inset LatexCommand \index{<file>.mem}
\end_inset
- of a function will be allocated to an overlayable segment if the function
- has
-\emph on
-no other function calls and the function is non-reentrant and the memory
- model
-\begin_inset LatexCommand \index{Memory model}
-
+ shows the final memory layout.
+ The linker will complain either if memory segments overlap, there is not
+ enough memory, or there is not enough space for stack.
+ If you get any linking warnings and/or errors related to stack or segments
+ allocation, take a look at either the .map or .mem files to find out what
+ the problem is.
+ The .mem file may even suggest a solution to the problem.
+\begin_inset VSpace bigskip
\end_inset
- is small.
-
-\emph default
- If an explicit storage class
-\begin_inset LatexCommand \index{Storage class}
-
-\end_inset
- is specified for a local variable, it will NOT be overlayed.
\end_layout
-\begin_layout Standard
-Note that the compiler (not the linkage editor) makes the decision for overlayin
-g the data items.
- Functions that are called from an interrupt service routine
-\begin_inset Marginal
-status collapsed
+\begin_layout Subsection
+Z80/Z180 Storage Class
+\begin_inset LatexCommand \index{Z80!Storage class}
-\begin_layout Standard
+\end_inset
-\series bold
-!
+ Language Extensions
\end_layout
+\begin_layout Subsubsection
+sfr
+\begin_inset LatexCommand \index{sfr}
+
\end_inset
- should be preceded by a #pragma\InsetSpace ~
-nooverlay
-\begin_inset LatexCommand \index{\#pragma nooverlay}
+
+\begin_inset LatexCommand \index{\_\_sfr}
\end_inset
- if they are not reentrant.
+ (in/out to 8-bit addresses)
\end_layout
\begin_layout Standard
-Also note that the compiler does not do any processing of inline assembler
- code, so the compiler might incorrectly assign local variables and parameters
- of a function into the overlay segment if the inline assembler code calls
- other c-functions that might use the overlay.
- In that case the #pragma\InsetSpace ~
-nooverlay should be used.
-\end_layout
+The Z80
+\begin_inset LatexCommand \index{Z80}
-\begin_layout Standard
-Parameters and local variables of functions that contain 16 or 32 bit multiplica
-tion
-\begin_inset LatexCommand \index{Multiplication}
+\end_inset
+
+ family has separate address spaces for memory and
+\emph on
+i
+\emph default
+nput/
+\emph on
+o
+\emph default
+utput memory.
+ I/O memory
+\begin_inset LatexCommand \index{I/O memory (Z80, Z180)}
\end_inset
- or division
-\begin_inset LatexCommand \index{Division}
+
+\begin_inset LatexCommand \index{Z80!I/O memory}
\end_inset
- will NOT be overlayed since these are implemented using external functions,
- e.g.:
+
+\begin_inset LatexCommand \index{Z180!I/O memory}
+
+\end_inset
+
+ is accessed with special instructions, e.g.:
\end_layout
\begin_layout Verse
\family typewriter
-#pragma save
-\newline
-#pragma nooverlay
-\begin_inset LatexCommand \index{\#pragma nooverlay}
+sfr at 0x78 IoPort;\InsetSpace ~
+\InsetSpace ~
+/* define a var in I/O space at 78h called IoPort */
-\end_inset
+\end_layout
-
-\newline
-void set_error(unsigned char errcd)
-\newline
-{
-\newline
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-P3 = errcd;
-\newline
-}
-\newline
-#pragma restore
-\newline
-
-\newline
-void
- some_isr () __interrupt
-\begin_inset LatexCommand \index{interrupt}
+\begin_layout Standard
+Writing 0x01 to this variable generates the assembly code:
+\end_layout
-\end_inset
+\begin_layout Verse
- (2)
-\newline
-{
-\newline
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
+\family typewriter
+3E 01\InsetSpace ~
\InsetSpace ~
-...
-\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-set_error(10);
+ld a,#0x01
\newline
+D3 78\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-...
-
-\newline
-}
+\InsetSpace ~
+out (_IoPort),a
\end_layout
-\begin_layout Standard
-In the above example the parameter
-\emph on
-errcd
-\emph default
- for the function
-\emph on
-set_error
-\emph default
- would be assigned to the overlayable segment if the #pragma\InsetSpace ~
-nooverlay was
- not present, this could cause unpredictable runtime behavior when called
- from an interrupt service routine.
- The #pragma\InsetSpace ~
-nooverlay ensures that the parameters and local variables for
- the function are NOT overlayed.
-\begin_inset VSpace bigskip
+\begin_layout Subsubsection
+banked sfr
+\begin_inset LatexCommand \index{sfr}
+
\end_inset
+\begin_inset LatexCommand \index{\_\_sfr}
+
+\end_inset
+
+ (in/out to 16-bit addresses)
\end_layout
-\begin_layout Section
-Interrupt Service Routines
-\begin_inset LatexCommand \label{sub:Interrupt-Service-Routines}
+\begin_layout Standard
+The keyword
+\emph on
+banked
+\emph default
+ is used to support 16 bit addresses in I/O memory e.g.:
+\end_layout
+
+\begin_layout Verse
+
+\family typewriter
+sfr banked at
+\begin_inset LatexCommand \index{at}
\end_inset
-\end_layout
+\begin_inset LatexCommand \index{\_\_at}
-\begin_layout Subsection
-General Information
+\end_inset
+
+ 0x123 IoPort;
\end_layout
\begin_layout Standard
-SDCC allows
-\emph on
-i
-\emph default
-nterrupt
-\emph on
-s
-\emph default
-ervice
-\emph on
-r
-\emph default
-outines to be coded in C, with some extended keywords.
+Writing 0x01 to this variable generates the assembly code:
\end_layout
\begin_layout Verse
\family typewriter
-void timer_isr (void) __interrupt (1) __using (1)
-\newline
-{
+01 23 01\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+ld bc,#_IoPort
\newline
+3E 01\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-...
-
+\InsetSpace ~
+ld a,#0x01
\newline
-}
+ED 79\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+out (c),a
\end_layout
-\begin_layout Standard
-The optional number following the
-\emph on
-interrupt
-\begin_inset LatexCommand \index{interrupt}
+\begin_layout Subsubsection
+sfr
+\begin_inset LatexCommand \index{sfr}
\end_inset
-\begin_inset LatexCommand \index{\_\_interrupt}
+\begin_inset LatexCommand \index{\_\_sfr}
\end_inset
-
-\emph default
- keyword is the interrupt number this routine will service.
- When present, the compiler will insert a call to this routine in the interrupt
- vector table
-\begin_inset LatexCommand \index{interrupt vector table}
+ (in0/out0 to 8 bit addresses on Z180
+\begin_inset LatexCommand \index{Z180}
\end_inset
- for the interrupt number specified.
- If you have multiple source files in your project, interrupt service routines
- can be present in any of them, but a prototype of the isr MUST be present
- or included in the file that contains the function
-\emph on
-main
-\emph default
-.
- The optional (8051 specific) keyword
-\emph on
-using
-\begin_inset LatexCommand \index{using (mcs51, ds390 register bank)}
+/HD64180
+\begin_inset LatexCommand \index{HD64180 (see Z180)}
\end_inset
+)
+\end_layout
-\begin_inset LatexCommand \index{\_\_using (mcs51, ds390 register bank)}
+\begin_layout Standard
+The compiler option -
+\begin_inset ERT
+status collapsed
-\end_inset
+\begin_layout Standard
-\emph default
- can be used to tell the compiler to use the specified register bank when
- generating code for this function.
-
-\newline
-Interrupt service routines open the door for some very interesting bugs:
+\backslash
+/
\end_layout
-\begin_layout Subsubsection
-\begin_inset LatexCommand \label{sub:Common-interrupt-pitfall-volatile}
-
\end_inset
-Common interrupt pitfall: variable not declared
-\emph on
-volatile
-\end_layout
+-portmode
+\begin_inset LatexCommand \index{Z180!Options!-\/-portmode}
-\begin_layout Standard
-If an interrupt service routine changes variables which are accessed by
- other functions these variables have to be declared
-\emph on
-volatile
-\emph default
+\end_inset
-\begin_inset LatexCommand \index{volatile}
+=180 (80) and a compiler #pragma\InsetSpace ~
+portmode
+\begin_inset LatexCommand \index{Z180!Pragmas!\#pragma portmode}
\end_inset
+ z180 (z80) is used to turn on (off) the Z180/HD64180 port addressing instructio
+ns
+\family typewriter
+in0/out0
+\family default
+ instead of
+\family typewriter
+in/out
+\family default
.
- See
-\begin_inset LatexCommand \url{http://en.wikipedia.org/wiki/Volatile_variable}
-
+ If you include the file z180.h this will be set automatically.
+\begin_inset VSpace bigskip
\end_inset
- .
+
\end_layout
-\begin_layout Subsubsection
-\begin_inset LatexCommand \label{sub:Common-interrupt-pitfall-non-atomic}
+\begin_layout Subsection
+HC08 Storage Class
+\begin_inset LatexCommand \index{HC08!Storage class}
\end_inset
-Common interrupt pitfall:
-\emph on
-non-atomic access
+ Language Extensions
\end_layout
-\begin_layout Standard
-If the access to these variables is not
-\emph on
-atomic
-\begin_inset LatexCommand \index{atomic}
-
-\end_inset
-
+\begin_layout Subsubsection
+data
+\begin_inset LatexCommand \index{data (hc08 storage class)}
-\emph default
- (i.e.
- the processor needs more than one instruction for the access and could
- be interrupted while accessing the variable) the interrupt must be disabled
- during the access to avoid inconsistent data.
-
-\newline
-Access to 16 or 32 bit variables is obviously not atomic on 8 bit CPUs
- and should be protected by disabling interrupts.
- You're not automatically on the safe side if you use 8 bit variables though.
- We need an example here: f.e.
- on the 8051 the harmless looking
-\begin_inset Quotes srd
\end_inset
-\family typewriter
-flags\InsetSpace ~
-|=\InsetSpace ~
-0x80;
-\family default
-
-\begin_inset Quotes sld
-\end_inset
+\begin_inset LatexCommand \index{\_\_data (hc08 storage class)}
- is not atomic if
-\family typewriter
-flags
-\family default
- resides in xdata.
- Setting
-\begin_inset Quotes srd
\end_inset
-\family typewriter
-flags\InsetSpace ~
-|=\InsetSpace ~
-0x40;
-\family default
+\end_layout
-\begin_inset Quotes sld
-\end_inset
+\begin_layout Standard
+The data storage class declares a variable that resides in the first 256
+ bytes of memory (the direct page).
+ The HC08
+\begin_inset LatexCommand \index{HC08}
- from within an interrupt routine might get lost if the interrupt occurs
- at the wrong time.
-
-\begin_inset Quotes sld
\end_inset
+ is most efficient at accessing variables (especially pointers) stored here.
+\end_layout
-\family typewriter
-counter\InsetSpace ~
-+=\InsetSpace ~
-8;
-\family default
+\begin_layout Subsubsection
+xdata
+\begin_inset LatexCommand \index{xdata (hc08 storage class)}
-\begin_inset Quotes srd
\end_inset
- is not atomic on the 8051 even if
-\family typewriter
-counter
-\family default
- is located in data memory.
-\newline
-Bugs like these are hard to reproduce and can
- cause a lot of trouble.
-
-\end_layout
-\begin_layout Subsubsection
-\begin_inset LatexCommand \label{sub:Common-interrupt-pitfall-stack-overflow}
+\begin_inset LatexCommand \index{\_\_xdata (hc08 storage class)}
\end_inset
-Common interrupt pitfall:
-\emph on
-stack overflow
+
\end_layout
\begin_layout Standard
-The return address and the registers used in the interrupt service routine
- are saved on the stack
-\begin_inset LatexCommand \index{stack}
+The xdata storage class declares a variable that can reside anywhere in
+ memory.
+ This is the default if no storage class is specified.
+\begin_inset VSpace bigskip
\end_inset
- so there must be sufficient stack space.
- If there isn't variables or registers (or even the return address itself)
- will be corrupted.
- This
-\emph on
-stack overflow
-\emph default
-\begin_inset LatexCommand \index{stack overflow}
+\end_layout
-\end_inset
+\begin_layout Section
+Absolute Addressing
+\begin_inset LatexCommand \index{Absolute addressing}
- is most likely to happen if the interrupt occurs during the
-\begin_inset Quotes sld
\end_inset
-deepest
-\begin_inset Quotes srd
-\end_inset
- subroutine when the stack is already in use for f.e.
- many return addresses.
\end_layout
-\begin_layout Subsubsection
-\begin_inset LatexCommand \label{sub:Common-interrupt-pitfall-non-reentrant}
+\begin_layout Standard
+Data items can be assigned an absolute address with the
+\emph on
+at
+\begin_inset LatexCommand \index{at}
\end_inset
-Common interrupt pitfall:
-\emph on
-use of non-reentrant functions
-\end_layout
-\begin_layout Standard
-A special note here, int (16 bit) and long (32 bit) integer division
-\begin_inset LatexCommand \index{Division}
+\begin_inset LatexCommand \index{\_\_at}
\end_inset
-, multiplication
-\begin_inset LatexCommand \index{Multiplication}
+ <address>
+\emph default
+ keyword, in addition to a storage class, e.g.:
+\end_layout
-\end_inset
+\begin_layout Verse
- & modulus
-\begin_inset LatexCommand \index{Modulus}
+\family typewriter
+xdata
+\begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
\end_inset
- and floating-point
-\begin_inset LatexCommand \index{Floating point support}
+
+\begin_inset LatexCommand \index{\_\_xdata (mcs51, ds390 storage class)}
\end_inset
- operations are implemented using external support routines.
- If an interrupt service routine needs to do any of these operations then
- the support routines (as mentioned in a following section) will have to
- be recompiled using the
-\emph on
- -
-\begin_inset ERT
-status collapsed
+ at
+\begin_inset LatexCommand \index{at}
-\begin_layout Standard
+\end_inset
-\backslash
-/
-\end_layout
+\begin_inset LatexCommand \index{\_\_at}
\end_inset
--stack-auto
-\begin_inset LatexCommand \index{-\/-stack-auto}
+ 0x7ffe unsigned int chksum;
+\end_layout
-\end_inset
+\begin_layout Standard
+or, better conforming to ISO/IEC 9899 C:
+\end_layout
+\begin_layout Verse
-\emph default
- option and the source file will need to be compiled using the
+\family typewriter
+__xdata __at (0x7ffe) unsigned int chksum;
+\end_layout
+
+\begin_layout Standard
+In the above example the variable chksum will be located at 0x7ffe and 0x7fff
+ of the external ram.
+ The compiler does
\emph on
--
-\begin_inset ERT
+not
+\emph default
+ reserve any space for variables declared in this way
+\begin_inset Marginal
status collapsed
\begin_layout Standard
-
-\backslash
-/
+\series bold
+\InsetSpace ~
+!
\end_layout
\end_inset
--int-long-reent
-\emph default
+ (they are implemented with an equate in the assembler).
+ Thus it is left to the programmer to make sure there are no overlaps with
+ other variables that are declared without the absolute address.
+ The assembler listing file (.lst
+\begin_inset LatexCommand \index{<file>.lst}
-\begin_inset LatexCommand \index{-\/-int-long-reent}
+\end_inset
+
+) and the linker output files (.rst
+\begin_inset LatexCommand \index{<file>.rst}
\end_inset
- compiler option.
-
-\newline
-Note, the type promotion
-\begin_inset LatexCommand \index{type promotion}
+) and (.map
+\begin_inset LatexCommand \index{<file>.map}
\end_inset
- required by ANSI C can cause 16 bit routines to be used
-\begin_inset Marginal
-status collapsed
+) are good places to look for such overlaps.
+\end_layout
\begin_layout Standard
+If however you provide an initializer
+\begin_inset LatexCommand \index{Variable initialization}
-\series bold
-\InsetSpace ~
-!
+\end_inset
+
+ actual memory allocation will take place and overlaps will be detected
+ by the linker.
+ E.g.:
\end_layout
-\end_inset
+\begin_layout Verse
- without the programmer being aware of it.
- See f.e.
- the cast
\family typewriter
-(unsigned char)(tail-1)
-\family default
- within the if clause in section
-\begin_inset LatexCommand \ref{sub:A-Step-by Assembler Introduction}
+__code __at (0x7ff0) char Id[5] =
+\begin_inset Quotes sld
+\end_inset
+SDCC
+\begin_inset Quotes srd
\end_inset
-.
+;
\end_layout
\begin_layout Standard
-Calling other functions from an interrupt service routine is not recommended,
- avoid it if possible.
- Note that when some function is called from an interrupt service routine
- it should be preceded by a #pragma\InsetSpace ~
-nooverlay
-\begin_inset LatexCommand \index{\#pragma nooverlay}
-
-\end_inset
+In the above example the variable Id will be located from 0x7ff0 to 0x7ff4
+ in code memory.
+\end_layout
- if it is not reentrant.
- Furthermore nonreentrant functions should not be called from the main program
- while the interrupt service routine might be active.
- They also must not be called from low priority interrupt service routines
- while a high priority interrupt service routine might be active.
- You could use semaphores or make the function
+\begin_layout Standard
+In case of memory mapped I/O devices the keyword
\emph on
- critical
+volatile
\emph default
- if all parameters are passed in registers.
-\newline
- Also see section
-\begin_inset LatexCommand \ref{sub:Overlaying}
+ has to be used to tell the compiler that accesses might not be removed:
+\end_layout
-\end_inset
+\begin_layout Verse
-\InsetSpace ~
-about Overlaying and section
-\begin_inset LatexCommand \ref{sub:Functions-using-private-banks}
+\family typewriter
+volatile
+\begin_inset LatexCommand \index{volatile}
\end_inset
-\InsetSpace ~
-about Functions using private register banks.
-\begin_inset VSpace bigskip
+ __xdata
+\begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
+
\end_inset
+ __at
+\begin_inset LatexCommand \index{at}
-\end_layout
+\end_inset
-\begin_layout Subsection
-MCS51/DS390 Interrupt Service Routines
+ (0x8000) unsigned char PORTA_8255;
\end_layout
\begin_layout Standard
-Interrupt
-\begin_inset LatexCommand \index{interrupt}
+For some architectures (mcs51) array accesses are more efficient if an (xdata/fa
+r) array
+\family typewriter
+\size footnotesize
+
+\begin_inset LatexCommand \index{Aligned array}
\end_inset
- numbers and the corresponding address & descriptions for the Standard 8051/8052
- are listed below.
- SDCC will automatically adjust the
-\begin_inset LatexCommand \index{interrupt vector table}
+
+\family default
+\size default
+ starts at a block (256 byte) boundary
+\begin_inset LatexCommand \index{block boundary}
\end_inset
- to the maximum interrupt number specified.
-\newline
+ (section
+\begin_inset LatexCommand \ref{sub:A-Step-by Assembler Introduction}
+\end_inset
+
+ has an example).
+\newline
+Absolute addresses can be specified for variables in all
+ storage classes, e.g.:
\end_layout
-\begin_layout Standard
-\align center
-\begin_inset Tabular
-<lyxtabular version="3" rows="9" columns="3">
-<features>
-<column alignment="center" valignment="top" leftline="true" width="0in">
-<column alignment="left" valignment="top" leftline="true" width="0in">
-<column alignment="left" valignment="top" leftline="true" rightline="true" width="0in">
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\begin_layout Verse
-\begin_layout Standard
-Interrupt #
-\end_layout
+\family typewriter
+__bit
+\begin_inset LatexCommand \index{bit}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
-Description
-\end_layout
+ __at
+\begin_inset LatexCommand \index{at}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
+ (0x02) bvar;
+\end_layout
+
+\begin_layout Standard
+The above example will allocate the variable at offset 0x02 in the bit-addressab
+le space.
+ There is no real advantage to assigning absolute addresses to variables
+ in this manner, unless you want strict control over all the variables allocated.
+ One possible use would be to write hardware portable code.
+ For example, if you have a routine that uses one or more of the microcontroller
+ I/O pins, and such pins are different for two different hardwares, you
+ can declare the I/O pins in your routine using:
+\end_layout
+
+\begin_layout Verse
+
+\family typewriter
+extern volatile
+\begin_inset LatexCommand \index{volatile}
+
+\end_inset
+
+ __bit MOSI;\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+/* master out, slave in */
+\newline
+extern volatile __bit MISO;\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+/* master
+ in, slave out */
+\newline
+extern volatile __bit MCLK;\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+/* master clock */
+\newline
+
+\newline
+/* Input and
+ Output of a byte on a 3-wire serial bus.
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+If needed adapt polarity of clock,
+ polarity of data and bit order
+\newline
+\InsetSpace ~
+*/
+\newline
+unsigned char spi_io(unsigned char out_byte)
+
+\newline
+{
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+unsigned char i=8;
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+do {
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+MOSI = out_byte & 0x80;
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+out_byte <<= 1;
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+MCLK =
+ 1;
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+/* _asm nop _endasm; */\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+/* for slow peripherals */
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+if(MISO)
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+out_byte +=
+ 1;
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+MCLK = 0;
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+} while(--i);
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+return out_byte;
+\newline
+}
+\end_layout
+
+\begin_layout Standard
+Then, someplace in the code for the first hardware you would use
+\end_layout
+
+\begin_layout Verse
+
+\family typewriter
+__bit __at
+\begin_inset LatexCommand \index{at}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_at}
+
+\end_inset
+
+ (0x80) MOSI;\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+/* I/O port 0, bit 0 */
+\newline
+__bit __at (0x81) MISO;\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+/* I/O port 0,
+ bit 1 */
+\newline
+__bit __at (0x82) MCLK;\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+/* I/O port 0, bit 2 */
+\end_layout
+
+\begin_layout Standard
+Similarly, for the second hardware you would use
+\end_layout
+
+\begin_layout Verse
+
+\family typewriter
+__bit __at (0x83) MOSI;\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+/* I/O port 0, bit 3 */
+\newline
+__bit __at (0x91) MISO;\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+/*
+ I/O port 1, bit 1 */
+\newline
+__bit
+\begin_inset LatexCommand \index{bit}
+
+\end_inset
+
+ __at (0x92) MCLK;\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+/* I/O port 1, bit 2 */
+\end_layout
+
+\begin_layout Standard
+and you can use the same hardware dependent routine without changes, as
+ for example in a library.
+ This is somehow similar to sbit, but only one absolute address has to be
+ specified in the whole project.
+\begin_inset VSpace bigskip
+\end_inset
+
+
+\end_layout
+
+\begin_layout Section
+Parameters
+\begin_inset LatexCommand \index{Parameters}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{function parameter}
+
+\end_inset
+
+ & Local Variables
+\begin_inset LatexCommand \index{local variables}
+
+\end_inset
+
+
+\begin_inset LatexCommand \label{sec:Parameters-and-Local-Variables}
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+Automatic (local) variables and parameters to functions can either be placed
+ on the stack or in data-space.
+ The default action of the compiler is to place these variables in the internal
+ RAM (for small model) or external RAM (for medium or large model).
+ This in fact makes them similar to
+\emph on
+static
+\begin_inset LatexCommand \index{static}
+
+\end_inset
+
+
+\emph default
+ so by default functions are non-reentrant
+\begin_inset LatexCommand \index{reentrant}
+
+\end_inset
+
+.
+
+\newline
+
+\newline
+They can be placed on the stack
+\begin_inset LatexCommand \index{stack}
+
+\end_inset
+
+ by using the
+\emph on
+ -
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-stack-auto
+\begin_inset LatexCommand \index{-\/-stack-auto}
+
+\end_inset
+
+
+\emph default
+ option, by using
+\emph on
+#pragma\InsetSpace ~
+stackauto
+\emph default
+
+\begin_inset LatexCommand \index{\#pragma stackauto}
+
+\end_inset
+
+ or by using the
+\emph on
+reentrant
+\begin_inset LatexCommand \index{reentrant}
+
+\end_inset
+
+
+\emph default
+ keyword in the function declaration, e.g.:
+\end_layout
+
+\begin_layout Verse
+
+\family typewriter
+unsigned char foo(char i) __reentrant
+\newline
+{
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+...
+
+\newline
+}
+\end_layout
+
+\begin_layout Standard
+Since stack space on 8051 is limited, the
+\emph on
+reentrant
+\emph default
+keyword or the
+\emph on
+ -
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-stack-auto
+\emph default
+ option should be used sparingly.
+ Note that the reentrant keyword just means that the parameters & local
+ variables will be allocated to the stack, it
+\emph on
+does not
+\emph default
+ mean that the function is register bank
+\begin_inset LatexCommand \index{register bank (mcs51, ds390)}
+
+\end_inset
+
+ independent.
+\newline
+
+\newline
+Local variables
+\begin_inset LatexCommand \index{local variables}
+
+\end_inset
+
+ can be assigned storage classes and absolute
+\begin_inset LatexCommand \index{Absolute addressing}
+
+\end_inset
+
+ addresses, e.g.:
+\end_layout
+
+\begin_layout Verse
+
+\family typewriter
+unsigned char foo()
+\newline
+{
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+__xdata unsigned char i;
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+__bit bvar;
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+__data __at
+\begin_inset LatexCommand \index{at}
+
+\end_inset
+
+ (0x31) unsigned char j;
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+...
+
+\newline
+}
+\end_layout
+
+\begin_layout Standard
+In the above example the variable
+\emph on
+i
+\emph default
+ will be allocated in the external ram,
+\emph on
+bvar
+\emph default
+ in bit addressable space and
+\emph on
+ j
+\emph default
+ in internal ram.
+ When compiled with
+\emph on
+-
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-stack-auto
+\emph default
+ or when a function is declared as
+\emph on
+reentrant
+\emph default
+ this should only be done for static variables.
+\end_layout
+
+\begin_layout Standard
+Parameters
+\begin_inset LatexCommand \index{function parameter}
+
+\end_inset
+
+ however are not allowed any storage class
+\begin_inset LatexCommand \index{Storage class}
+
+\end_inset
+
+, (storage classes for parameters will be ignored), their allocation is
+ governed by the memory model in use, and the reentrancy options.
+\end_layout
+
+\begin_layout Standard
+It is however allowed to use bit parameters in reentrant functions and also
+ non-static local bit variables are supported.
+ Efficient use is limited to 8 semi-bitregisters in bit space.
+ They are pushed and popped to stack
+\begin_inset LatexCommand \index{stack}
+
+\end_inset
+
+ as a single byte just like the normal registers.
+\end_layout
+
+\begin_layout Section
+Overlaying
+\begin_inset LatexCommand \label{sub:Overlaying}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Overlaying}
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+For non-reentrant
+\begin_inset LatexCommand \index{reentrant}
+
+\end_inset
+
+ functions SDCC will try to reduce internal ram space usage by overlaying
+ parameters and local variables of a function (if possible).
+ Parameters and local variables
+\begin_inset LatexCommand \index{local variables}
+
+\end_inset
+
+ of a function will be allocated to an overlayable segment if the function
+ has
+\emph on
+no other function calls and the function is non-reentrant and the memory
+ model
+\begin_inset LatexCommand \index{Memory model}
+
+\end_inset
+
+ is small.
+
+\emph default
+ If an explicit storage class
+\begin_inset LatexCommand \index{Storage class}
+
+\end_inset
+
+ is specified for a local variable, it will NOT be overlayed.
+\end_layout
+
+\begin_layout Standard
+Note that the compiler (not the linkage editor) makes the decision for overlayin
+g the data items.
+ Functions that are called from an interrupt service routine
+\begin_inset Marginal
+status collapsed
+
+\begin_layout Standard
+
+\series bold
+!
+\end_layout
+
+\end_inset
+
+ should be preceded by a #pragma\InsetSpace ~
+nooverlay
+\begin_inset LatexCommand \index{\#pragma nooverlay}
+
+\end_inset
+
+ if they are not reentrant.
+\end_layout
+
+\begin_layout Standard
+Also note that the compiler does not do any processing of inline assembler
+ code, so the compiler might incorrectly assign local variables and parameters
+ of a function into the overlay segment if the inline assembler code calls
+ other c-functions that might use the overlay.
+ In that case the #pragma\InsetSpace ~
+nooverlay should be used.
+\end_layout
+
+\begin_layout Standard
+Parameters and local variables of functions that contain 16 or 32 bit multiplica
+tion
+\begin_inset LatexCommand \index{Multiplication}
+
+\end_inset
+
+ or division
+\begin_inset LatexCommand \index{Division}
+
+\end_inset
+
+ will NOT be overlayed since these are implemented using external functions,
+ e.g.:
+\end_layout
+
+\begin_layout Verse
+
+\family typewriter
+#pragma save
+\newline
+#pragma nooverlay
+\begin_inset LatexCommand \index{\#pragma nooverlay}
+
+\end_inset
+
+
+\newline
+void set_error(unsigned char errcd)
+\newline
+{
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+P3 = errcd;
+\newline
+}
+\newline
+#pragma restore
+\newline
+
+\newline
+void
+ some_isr () __interrupt
+\begin_inset LatexCommand \index{interrupt}
+
+\end_inset
+
+ (2)
+\newline
+{
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+...
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+set_error(10);
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+...
+
+\newline
+}
+\end_layout
+
+\begin_layout Standard
+In the above example the parameter
+\emph on
+errcd
+\emph default
+ for the function
+\emph on
+set_error
+\emph default
+ would be assigned to the overlayable segment if the #pragma\InsetSpace ~
+nooverlay was
+ not present, this could cause unpredictable runtime behavior when called
+ from an interrupt service routine.
+ The #pragma\InsetSpace ~
+nooverlay ensures that the parameters and local variables for
+ the function are NOT overlayed.
+\begin_inset VSpace bigskip
+\end_inset
+
+
+\end_layout
+
+\begin_layout Section
+Interrupt Service Routines
+\begin_inset LatexCommand \label{sub:Interrupt-Service-Routines}
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Subsection
+General Information
+\end_layout
+
+\begin_layout Standard
+SDCC allows
+\emph on
+i
+\emph default
+nterrupt
+\emph on
+s
+\emph default
+ervice
+\emph on
+r
+\emph default
+outines to be coded in C, with some extended keywords.
+\end_layout
+
+\begin_layout Verse
+
+\family typewriter
+void timer_isr (void) __interrupt (1) __using (1)
+\newline
+{
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+...
+
+\newline
+}
+\end_layout
+
+\begin_layout Standard
+The optional number following the
+\emph on
+interrupt
+\begin_inset LatexCommand \index{interrupt}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_interrupt}
+
+\end_inset
+
+
+\emph default
+ keyword is the interrupt number this routine will service.
+ When present, the compiler will insert a call to this routine in the interrupt
+ vector table
+\begin_inset LatexCommand \index{interrupt vector table}
+
+\end_inset
+
+ for the interrupt number specified.
+ If you have multiple source files in your project, interrupt service routines
+ can be present in any of them, but a prototype of the isr MUST be present
+ or included in the file that contains the function
+\emph on
+main
+\emph default
+.
+ The optional (8051 specific) keyword
+\emph on
+using
+\begin_inset LatexCommand \index{using (mcs51, ds390 register bank)}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_using (mcs51, ds390 register bank)}
+
+\end_inset
+
+
+\emph default
+ can be used to tell the compiler to use the specified register bank when
+ generating code for this function.
+
+\newline
+Interrupt service routines open the door for some very interesting bugs:
+\end_layout
+
+\begin_layout Subsubsection
+\begin_inset LatexCommand \label{sub:Common-interrupt-pitfall-volatile}
+
+\end_inset
+
+Common interrupt pitfall: variable not declared
+\emph on
+volatile
+\end_layout
+
+\begin_layout Standard
+If an interrupt service routine changes variables which are accessed by
+ other functions these variables have to be declared
+\emph on
+volatile
+\emph default
+
+\begin_inset LatexCommand \index{volatile}
+
+\end_inset
+
+.
+ See
+\begin_inset LatexCommand \url{http://en.wikipedia.org/wiki/Volatile_variable}
+
+\end_inset
+
+ .
+\end_layout
+
+\begin_layout Subsubsection
+\begin_inset LatexCommand \label{sub:Common-interrupt-pitfall-non-atomic}
+
+\end_inset
+
+Common interrupt pitfall:
+\emph on
+non-atomic access
+\end_layout
+
+\begin_layout Standard
+If the access to these variables is not
+\emph on
+atomic
+\begin_inset LatexCommand \index{atomic}
+
+\end_inset
+
+
+\emph default
+ (i.e.
+ the processor needs more than one instruction for the access and could
+ be interrupted while accessing the variable) the interrupt must be disabled
+ during the access to avoid inconsistent data.
+
+\newline
+Access to 16 or 32 bit variables is obviously not atomic on 8 bit CPUs
+ and should be protected by disabling interrupts.
+ You're not automatically on the safe side if you use 8 bit variables though.
+ We need an example here: f.e.
+ on the 8051 the harmless looking
+\begin_inset Quotes srd
+\end_inset
+
+
+\family typewriter
+flags\InsetSpace ~
+|=\InsetSpace ~
+0x80;
+\family default
+
+\begin_inset Quotes sld
+\end_inset
+
+ is not atomic if
+\family typewriter
+flags
+\family default
+ resides in xdata.
+ Setting
+\begin_inset Quotes srd
+\end_inset
+
+
+\family typewriter
+flags\InsetSpace ~
+|=\InsetSpace ~
+0x40;
+\family default
+
+\begin_inset Quotes sld
+\end_inset
+
+ from within an interrupt routine might get lost if the interrupt occurs
+ at the wrong time.
+
+\begin_inset Quotes sld
+\end_inset
+
+
+\family typewriter
+counter\InsetSpace ~
++=\InsetSpace ~
+8;
+\family default
+
+\begin_inset Quotes srd
+\end_inset
+
+ is not atomic on the 8051 even if
+\family typewriter
+counter
+\family default
+ is located in data memory.
+\newline
+Bugs like these are hard to reproduce and can
+ cause a lot of trouble.
+
+\end_layout
+
+\begin_layout Subsubsection
+\begin_inset LatexCommand \label{sub:Common-interrupt-pitfall-stack-overflow}
+
+\end_inset
+
+Common interrupt pitfall:
+\emph on
+stack overflow
+\end_layout
+
+\begin_layout Standard
+The return address and the registers used in the interrupt service routine
+ are saved on the stack
+\begin_inset LatexCommand \index{stack}
+
+\end_inset
+
+ so there must be sufficient stack space.
+ If there isn't variables or registers (or even the return address itself)
+ will be corrupted.
+ This
+\emph on
+stack overflow
+\emph default
+
+\begin_inset LatexCommand \index{stack overflow}
+
+\end_inset
+
+ is most likely to happen if the interrupt occurs during the
+\begin_inset Quotes sld
+\end_inset
+
+deepest
+\begin_inset Quotes srd
+\end_inset
+
+ subroutine when the stack is already in use for f.e.
+ many return addresses.
+\end_layout
+
+\begin_layout Subsubsection
+\begin_inset LatexCommand \label{sub:Common-interrupt-pitfall-non-reentrant}
+
+\end_inset
+
+Common interrupt pitfall:
+\emph on
+use of non-reentrant functions
+\end_layout
+
+\begin_layout Standard
+A special note here, int (16 bit) and long (32 bit) integer division
+\begin_inset LatexCommand \index{Division}
+
+\end_inset
+
+, multiplication
+\begin_inset LatexCommand \index{Multiplication}
+
+\end_inset
+
+ & modulus
+\begin_inset LatexCommand \index{Modulus}
+
+\end_inset
+
+ and floating-point
+\begin_inset LatexCommand \index{Floating point support}
+
+\end_inset
+
+ operations are implemented using external support routines.
+ If an interrupt service routine needs to do any of these operations then
+ the support routines (as mentioned in a following section) will have to
+ be recompiled using the
+\emph on
+ -
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-stack-auto
+\begin_inset LatexCommand \index{-\/-stack-auto}
+
+\end_inset
+
+
+\emph default
+ option and the source file will need to be compiled using the
+\emph on
+-
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-int-long-reent
+\emph default
+
+\begin_inset LatexCommand \index{-\/-int-long-reent}
+
+\end_inset
+
+ compiler option.
+
+\newline
+Note, the type promotion
+\begin_inset LatexCommand \index{type promotion}
+
+\end_inset
+
+ required by ANSI C can cause 16 bit routines to be used
+\begin_inset Marginal
+status collapsed
+
+\begin_layout Standard
+
+\series bold
+\InsetSpace ~
+!
+\end_layout
+
+\end_inset
+
+ without the programmer being aware of it.
+ See f.e.
+ the cast
+\family typewriter
+(unsigned char)(tail-1)
+\family default
+ within the if clause in section
+\begin_inset LatexCommand \ref{sub:A-Step-by Assembler Introduction}
+
+\end_inset
+
+.
+\end_layout
+
+\begin_layout Standard
+Calling other functions from an interrupt service routine is not recommended,
+ avoid it if possible.
+ Note that when some function is called from an interrupt service routine
+ it should be preceded by a #pragma\InsetSpace ~
+nooverlay
+\begin_inset LatexCommand \index{\#pragma nooverlay}
+
+\end_inset
+
+ if it is not reentrant.
+ Furthermore nonreentrant functions should not be called from the main program
+ while the interrupt service routine might be active.
+ They also must not be called from low priority interrupt service routines
+ while a high priority interrupt service routine might be active.
+ You could use semaphores or make the function
+\emph on
+ critical
+\emph default
+ if all parameters are passed in registers.
+\newline
+ Also see section
+\begin_inset LatexCommand \ref{sub:Overlaying}
+
+\end_inset
+
+\InsetSpace ~
+about Overlaying and section
+\begin_inset LatexCommand \ref{sub:Functions-using-private-banks}
+
+\end_inset
+
+\InsetSpace ~
+about Functions using private register banks.
+\begin_inset VSpace bigskip
+\end_inset
+
+
+\end_layout
+
+\begin_layout Subsection
+MCS51/DS390 Interrupt Service Routines
+\end_layout
+
+\begin_layout Standard
+Interrupt
+\begin_inset LatexCommand \index{interrupt}
+
+\end_inset
+
+ numbers and the corresponding address & descriptions for the Standard 8051/8052
+ are listed below.
+ SDCC will automatically adjust the
+\begin_inset LatexCommand \index{interrupt vector table}
+
+\end_inset
+
+ to the maximum interrupt number specified.
+\newline
+
+\end_layout
+
+\begin_layout Standard
+\align center
+\begin_inset Tabular
+<lyxtabular version="3" rows="9" columns="3">
+<features>
+<column alignment="center" valignment="top" leftline="true" width="0in">
+<column alignment="left" valignment="top" leftline="true" width="0in">
+<column alignment="left" valignment="top" leftline="true" rightline="true" width="0in">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+Interrupt #
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+Description
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
Vector Address
\end_layout
\end_inset
</cell>
</row>
-<row topline="true">
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+0
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+External 0
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+0x0003
+\end_layout
+
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+1
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+Timer 0
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+0x000b
+\end_layout
+
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+2
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+External 1
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+0x0013
+\end_layout
+
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+3
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+Timer 1
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+0x001b
+\end_layout
+
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+4
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+Serial
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+0x0023
+\end_layout
+
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell multicolumn="1" alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+5
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+Timer 2 (8052)
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+0x002b
+\end_layout
+
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+...
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+...
+\end_layout
+
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\begin_layout Standard
-0
+n
\end_layout
\end_inset
\begin_inset Text
\begin_layout Standard
-External 0
+
\end_layout
\end_inset
\begin_inset Text
\begin_layout Standard
-0x0003
-\end_layout
+0x0003 + 8*n
+\end_layout
+
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\newline
+
+\end_layout
+
+\begin_layout Standard
+If the interrupt service routine is defined without
+\emph on
+using
+\begin_inset LatexCommand \index{using (mcs51, ds390 register bank)}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_using (mcs51, ds390 register bank)}
+
+\end_inset
+
+
+\emph default
+ a register bank or with register bank 0 (
+\emph on
+using
+\emph default
+ 0), the compiler will save the registers used by itself on the stack upon
+ entry and restore them at exit, however if such an interrupt service routine
+ calls another function then the entire register bank will be saved on the
+ stack.
+ This scheme may be advantageous for small interrupt service routines which
+ have low register usage.
+\end_layout
+
+\begin_layout Standard
+If the interrupt service routine is defined to be using a specific register
+ bank then only
+\emph on
+a, b, dptr
+\emph default
+ & psw are saved and restored, if such an interrupt service routine calls
+ another function (using another register bank) then the entire register
+ bank of the called function will be saved on the stack
+\begin_inset LatexCommand \index{stack}
+
+\end_inset
+
+.
+ This scheme is recommended for larger interrupt service routines.
+\begin_inset VSpace bigskip
+\end_inset
+
+
+\end_layout
+
+\begin_layout Subsection
+HC08
+\begin_inset LatexCommand \index{HC08}
+
+\end_inset
+
+ Interrupt Service Routines
+\end_layout
+
+\begin_layout Standard
+Since the number of interrupts
+\begin_inset LatexCommand \index{HC08!interrupt}
+
+\end_inset
+
+ available is chip specific and the interrupt vector table always ends at
+ the last byte of memory, the interrupt numbers corresponds to the interrupt
+ vectors in reverse order of address.
+ For example, interrupt 1 will use the interrupt vector at 0xfffc, interrupt
+ 2 will use the interrupt vector at 0xfffa, and so on.
+ However, interrupt 0 (the reset vector at 0xfffe) is not redefinable in
+ this way; instead see section
+\begin_inset LatexCommand \ref{sub:Startup-Code}
+
+\end_inset
+
+ for details on customizing startup.
+\begin_inset VSpace bigskip
+\end_inset
+
+
+\end_layout
+
+\begin_layout Subsection
+Z80 Interrupt Service Routines
+\end_layout
+
+\begin_layout Standard
+The Z80
+\begin_inset LatexCommand \index{Z80}
+
+\end_inset
+
+ uses several different methods for determining the correct interrupt
+\begin_inset LatexCommand \index{Z80!interrupt}
+
+\end_inset
+
+ vector depending on the hardware implementation.
+ Therefore, SDCC ignores the optional interrupt number and does not attempt
+ to generate an interrupt vector table.
+\end_layout
+
+\begin_layout Standard
+By default, SDCC generates code for a maskable interrupt, which uses a RETI
+ instruction to return from the interrupt.
+ To write an interrupt handler for the non-maskable interrupt, which needs
+ a RETN instruction instead, add the
+\emph on
+critical
+\emph default
+ keyword:
+\end_layout
+
+\begin_layout Verse
+
+\family typewriter
+void nmi_isr (void) critical interrupt
+\newline
+{
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+...
+
+\newline
+}
+\end_layout
+
+\begin_layout Standard
+However if you need to create a non-interruptable interrupt service routine
+ you would also require the
+\emph on
+critical
+\emph default
+ keyword.
+ To distinguish between this and an nmi_isr you must provide an interrupt
+ number.
+\begin_inset VSpace bigskip
+\end_inset
+
+
+\end_layout
+
+\begin_layout Section
+Enabling and Disabling Interrupts
+\end_layout
+
+\begin_layout Subsection
+Critical Functions and Critical Statements
+\end_layout
+
+\begin_layout Standard
+A special keyword may be associated with a block or a function declaring
+ it as
+\emph on
+critical
+\emph default
+.
+ SDCC will generate code to disable all interrupts
+\begin_inset LatexCommand \index{interrupt}
+
+\end_inset
+
+ upon entry to a critical function and restore the interrupt enable to the
+ previous state before returning.
+ Nesting critical functions will need one additional byte on the stack
+\begin_inset LatexCommand \index{stack}
+
+\end_inset
+
+ for each call.
+\end_layout
+
+\begin_layout Verse
+
+\family typewriter
+int foo () __critical
+\begin_inset LatexCommand \index{critical}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_critical}
+
+\end_inset
+
+
+\newline
+{
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+...
+
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+...
+
+\newline
+}
+\end_layout
+
+\begin_layout Standard
+The critical attribute maybe used with other attributes like
+\emph on
+reentrant.
+\emph default
+
+\newline
+The keyword
+\emph on
+critical
+\emph default
+ may also be used to disable interrupts more locally:
+\end_layout
+
+\begin_layout Verse
+
+\family typewriter
+__critical{ i++; }
+\end_layout
+
+\begin_layout Standard
+More than one statement could have been included in the block.
+\end_layout
+
+\begin_layout Subsection
+Enabling and Disabling Interrupts directly
+\end_layout
+
+\begin_layout Standard
+Interrupts
+\begin_inset LatexCommand \index{interrupt}
+
+\end_inset
+
+ can also be disabled and enabled directly (8051):
+\end_layout
+
+\begin_layout Verse
+
+\family typewriter
+EA = 0;\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+or:\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+EA_SAVE = EA;
+\end_layout
+
+\begin_layout Verse
+
+\family typewriter
+...\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+EA = 0;
+\end_layout
+
+\begin_layout Verse
+
+\family typewriter
+EA = 1;\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+...
+\end_layout
+
+\begin_layout Verse
+
+\family typewriter
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+EA = EA_SAVE;
+\end_layout
+
+\begin_layout Standard
+On other architectures which have seperate opcodes for enabling and disabling
+ interrupts you might want to make use of defines with inline assembly
+\begin_inset LatexCommand \index{Assembler routines}
+
+\end_inset
+
+ (HC08
+\begin_inset LatexCommand \index{HC08!interrupt}
+
+\end_inset
+
+):
+\end_layout
+
+\begin_layout Verse
+
+\family typewriter
+#define CLI _asm
+\begin_inset LatexCommand \index{\_asm}
+
+\end_inset
+
+\InsetSpace ~
+\InsetSpace ~
+cli\InsetSpace ~
+\InsetSpace ~
+_endasm
+\begin_inset LatexCommand \index{\_endasm}
+
+\end_inset
+
+;
+\end_layout
+
+\begin_layout Verse
+
+\family typewriter
+#define SEI _asm\InsetSpace ~
+\InsetSpace ~
+sei\InsetSpace ~
+\InsetSpace ~
+_endasm;
+\end_layout
+
+\begin_layout Verse
+
+\family typewriter
+...
+\end_layout
+
+\begin_layout Standard
+Note: it is sometimes sufficient to disable only a specific interrupt source
+ like f.e.
+ a timer or serial interrupt by manipulating an
+\emph on
+interrupt mask
+\begin_inset LatexCommand \index{interrupt mask}
+
+\end_inset
+
+
+\emph default
+ register.
+
+\end_layout
+
+\begin_layout Standard
+Usually the time during which interrupts are disabled should be kept as
+ short as possible.
+ This minimizes both
+\emph on
+interrupt latency
+\emph default
+
+\begin_inset LatexCommand \index{interrupt latency}
+
+\end_inset
+
+ (the time between the occurrence of the interrupt and the execution of
+ the first code in the interrupt routine) and
+\emph on
+interrupt jitter
+\emph default
+
+\begin_inset LatexCommand \index{interrupt jitter}
+
+\end_inset
+
+ (the difference between the shortest and the longest interrupt latency).
+ These really are something different, f.e.
+ a serial interrupt has to be served before its buffer overruns so it cares
+ for the maximum interrupt latency, whereas it does not care about jitter.
+ On a loudspeaker driven via a digital to analog converter which is fed
+ by an interrupt a latency of a few milliseconds might be tolerable, whereas
+ a much smaller jitter will be very audible.
+\end_layout
+
+\begin_layout Standard
+You can reenable interrupts within an interrupt routine and on some architecture
+s you can make use of two (or more) levels of
+\emph on
+interrupt priorities
+\emph default
+
+\begin_inset LatexCommand \index{interrupt priority}
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
-1
-\end_layout
+.
+ On some architectures which don't support interrupt priorities these can
+ be implemented by manipulating the interrupt mask and reenabling interrupts
+ within the interrupt routine.
+ Check there is sufficient space on the stack
+\begin_inset LatexCommand \index{stack}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
-Timer 0
+ and don't add complexity unless you have to.
+
\end_layout
+\begin_layout Subsection
+Semaphore
+\begin_inset LatexCommand \index{semaphore}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
-0x000b
+ locking (mcs51/ds390)
\end_layout
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
\begin_layout Standard
-2
-\end_layout
+Some architectures (mcs51/ds390) have an atomic
+\begin_inset LatexCommand \index{atomic}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
-External 1
-\end_layout
+ bit test and
+\emph on
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+\emph default
+clear
+\emph on
-\begin_layout Standard
-0x0013
-\end_layout
+\emph default
+instruction.
+ These type of instructions are typically used in preemptive multitasking
+ systems, where a routine f.e.
+ claims the use of a data structure ('acquires a lock
+\begin_inset LatexCommand \index{lock}
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
-3
-\end_layout
+ on it'), makes some modifications and then releases the lock when the data
+ structure is consistent again.
+ The instruction may also be used if interrupt and non-interrupt code have
+ to compete for a resource.
+ With the atomic bit test and clear instruction interrupts
+\begin_inset LatexCommand \index{interrupt}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
-Timer 1
-\end_layout
+ don't have to be disabled for the locking operation.
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+\end_layout
\begin_layout Standard
-0x001b
+SDCC generates this instruction if the source follows this pattern:
\end_layout
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\begin_layout Verse
-\begin_layout Standard
-4
-\end_layout
+\family typewriter
+volatile
+\begin_inset LatexCommand \index{volatile}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
-Serial
-\end_layout
+ bit resource_is_free;
+\newline
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+\newline
+if (resource_is_free)
+\newline
+\InsetSpace ~
+\InsetSpace ~
+{
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+resource_is_free=0;
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+...
-\begin_layout Standard
-0x0023
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+resource_is_free=1;
+\newline
+\InsetSpace ~
+\InsetSpace ~
+}
\end_layout
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell multicolumn="1" alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
\begin_layout Standard
-5
-\end_layout
+Note, mcs51 and ds390 support only an atomic
+\begin_inset LatexCommand \index{atomic}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
-Timer 2 (8052)
+ bit test and
+\emph on
+clear
+\emph default
+ instruction (as opposed to atomic bit test and
+\emph on
+set).
\end_layout
+\begin_layout Section
+Functions using private register banks
+\begin_inset LatexCommand \label{sub:Functions-using-private-banks}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
-0x002b
+ (mcs51/ds390)
\end_layout
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
\begin_layout Standard
-...
-\end_layout
+Some architectures have support for quickly changing register sets.
+ SDCC supports this feature with the
+\emph on
+using
+\begin_inset LatexCommand \index{using (mcs51, ds390 register bank)}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
-\end_layout
+\begin_inset LatexCommand \index{\_\_using (mcs51, ds390 register bank)}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
-...
-\end_layout
+
+\emph default
+ attribute (which tells the compiler to use a register bank
+\begin_inset LatexCommand \index{register bank (mcs51, ds390)}
\end_inset
-</cell>
-</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
-n
-\end_layout
+ other than the default bank zero).
+ It should only be applied to
+\emph on
+interrupt
+\begin_inset LatexCommand \index{interrupt}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
+\emph default
+ functions (see footnote below).
+ This will in most circumstances make the generated ISR code more efficient
+ since it will not have to save registers on the stack.
\end_layout
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+\begin_layout Standard
+The
+\emph on
+using
+\emph default
+ attribute will have no effect on the generated code for a
+\emph on
+non-interrupt
+\emph default
+ function (but may occasionally be useful anyway
+\begin_inset Foot
+status open
\begin_layout Standard
-0x0003 + 8*n
+possible exception: if a function is called ONLY from 'interrupt' functions
+ using a particular bank, it can be declared with the same 'using' attribute
+ as the calling 'interrupt' functions.
+ For instance, if you have several ISRs using bank one, and all of them
+ call memcpy(), it might make sense to create a specialized version of memcpy()
+ 'using 1', since this would prevent the ISR from having to save bank zero
+ to the stack on entry and switch to bank zero before calling the function
\end_layout
\end_inset
-</cell>
-</row>
-</lyxtabular>
-
-\end_inset
-
+).
\newline
+\emph on
+(pending: Note, nowadays the
+\emph default
+using
+\emph on
+ attribute has an effect on
+\emph default
+
+\emph on
+the generated code for a
+\emph default
+non-interrupt
+\emph on
+ function
+\emph default
+.
+\emph on
+)
\end_layout
\begin_layout Standard
-If the interrupt service routine is defined without
+An
\emph on
-using
-\begin_inset LatexCommand \index{using (mcs51, ds390 register bank)}
+interrupt
+\emph default
+ function using a non-zero bank will assume that it can trash that register
+ bank, and will not save it.
+ Since high-priority interrupts
+\begin_inset LatexCommand \index{interrupts}
\end_inset
-\begin_inset LatexCommand \index{\_\_using (mcs51, ds390 register bank)}
+\begin_inset LatexCommand \index{interrupt priority}
\end_inset
-
+ can interrupt low-priority ones on the 8051 and friends, this means that
+ if a high-priority ISR
+\emph on
+using
\emph default
- a register bank or with register bank 0 (
+ a particular bank occurs while processing a low-priority ISR
\emph on
using
\emph default
- 0), the compiler will save the registers used by itself on the stack upon
- entry and restore them at exit, however if such an interrupt service routine
- calls another function then the entire register bank will be saved on the
- stack.
- This scheme may be advantageous for small interrupt service routines which
- have low register usage.
-\end_layout
-
-\begin_layout Standard
-If the interrupt service routine is defined to be using a specific register
- bank then only
+ the same bank, terrible and bad things can happen.
+ To prevent this, no single register bank should be
\emph on
-a, b, dptr
+used
\emph default
- & psw are saved and restored, if such an interrupt service routine calls
- another function (using another register bank) then the entire register
- bank of the called function will be saved on the stack
-\begin_inset LatexCommand \index{stack}
+ by both a high priority and a low priority ISR.
+ This is probably most easily done by having all high priority ISRs use
+ one bank and all low priority ISRs use another.
+ If you have an ISR which can change priority at runtime, you're on your
+ own: I suggest using the default bank zero and taking the small performance
+ hit.
+\end_layout
-\end_inset
+\begin_layout Standard
+It is most efficient if your ISR calls no other functions.
+ If your ISR must call other functions, it is most efficient if those functions
+ use the same bank as the ISR (see note 1 below); the next best is if the
+ called functions use bank zero.
+ It is very inefficient to call a function using a different, non-zero bank
+ from an ISR.
-.
- This scheme is recommended for larger interrupt service routines.
\begin_inset VSpace bigskip
\end_inset
\end_layout
-\begin_layout Subsection
-HC08
-\begin_inset LatexCommand \index{HC08}
-
-\end_inset
-
- Interrupt Service Routines
-\end_layout
-
-\begin_layout Standard
-Since the number of interrupts
-\begin_inset LatexCommand \index{HC08!interrupt}
+\begin_layout Section
+Startup Code
+\begin_inset LatexCommand \label{sub:Startup-Code}
\end_inset
- available is chip specific and the interrupt vector table always ends at
- the last byte of memory, the interrupt numbers corresponds to the interrupt
- vectors in reverse order of address.
- For example, interrupt 1 will use the interrupt vector at 0xfffc, interrupt
- 2 will use the interrupt vector at 0xfffa, and so on.
- However, interrupt 0 (the reset vector at 0xfffe) is not redefinable in
- this way; instead see section
-\begin_inset LatexCommand \ref{sub:Startup-Code}
-\end_inset
+\begin_inset LatexCommand \index{Startup code}
- for details on customizing startup.
-\begin_inset VSpace bigskip
\end_inset
\end_layout
\begin_layout Subsection
-Z80 Interrupt Service Routines
+MCS51/DS390 Startup Code
\end_layout
\begin_layout Standard
-The Z80
-\begin_inset LatexCommand \index{Z80}
+The compiler triggers the linker to link certain initialization modules
+ from the runtime library
+\begin_inset LatexCommand \index{Runtime library}
\end_inset
- uses several different methods for determining the correct interrupt
-\begin_inset LatexCommand \index{Z80!interrupt}
+ called crt<something>.
+ Only the necessary ones are linked, for instance crtxstack.asm (GSINIT1,
+ GSINIT5) is not linked unless the -
+\series bold
+
+\begin_inset ERT
+status open
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
\end_inset
- vector depending on the hardware implementation.
- Therefore, SDCC ignores the optional interrupt number and does not attempt
- to generate an interrupt vector table.
+
+\series default
+-xstack option is used.
+ These modules are highly entangled by the use of special segments/areas,
+ but a common layout is shown below:
\end_layout
-\begin_layout Standard
-By default, SDCC generates code for a maskable interrupt, which uses a RETI
- instruction to return from the interrupt.
- To write an interrupt handler for the non-maskable interrupt, which needs
- a RETN instruction instead, add the
-\emph on
-critical
-\emph default
- keyword:
+\begin_layout Verse
+
+\family typewriter
+\series bold
+\size footnotesize
+(main.asm)
\end_layout
\begin_layout Verse
\family typewriter
-void nmi_isr (void) critical interrupt
+\size footnotesize
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+.area HOME (CODE)
\newline
-{
+__interrupt_vect:
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-...
-
-\newline
-}
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+ljmp __sdcc_gsinit_startup
\end_layout
-\begin_layout Standard
-However if you need to create a non-interruptable interrupt service routine
- you would also require the
-\emph on
-critical
-\emph default
- keyword.
- To distinguish between this and an nmi_isr you must provide an interrupt
- number.
-\begin_inset VSpace bigskip
-\end_inset
-
+\begin_layout Verse
+\family typewriter
+\series bold
+\size footnotesize
+(crtstart.asm)
\end_layout
-\begin_layout Section
-Enabling and Disabling Interrupts
-\end_layout
+\begin_layout Verse
-\begin_layout Subsection
-Critical Functions and Critical Statements
+\family typewriter
+\size footnotesize
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+.area GSINIT0 (CODE)
+\newline
+__sdcc_gsinit_startup::
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+mov sp,#__start__stack - 1
\end_layout
-\begin_layout Standard
-A special keyword may be associated with a block or a function declaring
- it as
-\emph on
-critical
-\emph default
-.
- SDCC will generate code to disable all interrupts
-\begin_inset LatexCommand \index{interrupt}
-
-\end_inset
-
- upon entry to a critical function and restore the interrupt enable to the
- previous state before returning.
- Nesting critical functions will need one additional byte on the stack
-\begin_inset LatexCommand \index{stack}
-
-\end_inset
+\begin_layout Verse
- for each call.
+\family typewriter
+\series bold
+\size footnotesize
+(crtxstack.asm)
\end_layout
\begin_layout Verse
\family typewriter
-int foo () __critical
-\begin_inset LatexCommand \index{critical}
-
-\end_inset
+\size footnotesize
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+.area GSINIT1 (CODE)
+\newline
+__sdcc_init_xstack::
+\newline
+; Need to initialize in GSINIT1 in
+ case the user's __sdcc_external_startup uses the xstack.
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+mov __XPAGE,#(__start__x
+stack >> 8)
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+mov _spx,#__start__xstack
+\end_layout
+\begin_layout Verse
-\begin_inset LatexCommand \index{\_\_critical}
+\family typewriter
+\series bold
+\size footnotesize
+(crtstart.asm)
+\end_layout
-\end_inset
+\begin_layout Verse
-
+\family typewriter
+\size footnotesize
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+.area GSINIT2 (CODE)
\newline
-{
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+lcall __sdcc_external_startup
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-...
-
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+mov a,dpl
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-...
-
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+jz __sdcc_init_data
\newline
-}
-\end_layout
-
-\begin_layout Standard
-The critical attribute maybe used with other attributes like
-\emph on
-reentrant.
-\emph default
-
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+ljmp
+ __sdcc_program_startup
\newline
-The keyword
-\emph on
-critical
-\emph default
- may also be used to disable interrupts more locally:
+__sdcc_init_data:
\end_layout
\begin_layout Verse
\family typewriter
-__critical{ i++; }
-\end_layout
-
-\begin_layout Standard
-More than one statement could have been included in the block.
-\end_layout
-
-\begin_layout Subsection
-Enabling and Disabling Interrupts directly
-\end_layout
-
-\begin_layout Standard
-Interrupts
-\begin_inset LatexCommand \index{interrupt}
-
-\end_inset
-
- can also be disabled and enabled directly (8051):
+\series bold
+\size footnotesize
+(crtxinit.asm)
\end_layout
\begin_layout Verse
\family typewriter
-EA = 0;\InsetSpace ~
+\size footnotesize
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
+.area GSINIT3 (CODE)
+\newline
+__mcs51_genXINIT::
+\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-or:\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
+mov r1,#l_XINIT
+\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-EA_SAVE = EA;
-\end_layout
-
-\begin_layout Verse
-
-\family typewriter
-...\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
+mov a,r1
+\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
+orl a,#(l_XINIT
+ >> 8)
+\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
+jz 00003$
+\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
+mov r2,#((l_XINIT+255) >> 8)
+\newline
\InsetSpace ~
\InsetSpace ~
-EA = 0;
-\end_layout
-
-\begin_layout Verse
-
-\family typewriter
-EA = 1;\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
+mov dptr,#s_XINIT
+\newline
+\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
+mov r0,#s_XISEG
+\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
+mov
+ __XPAGE,#(s_XISEG >> 8)
+\newline
+00001$:\InsetSpace ~
+clr a
+\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-...
-\end_layout
-
-\begin_layout Verse
-
-\family typewriter
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
+movc a,@a+dptr
+\newline
+\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
+movx @r0,a
+\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
+inc dptr
+\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
+inc
+ r0
+\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-EA = EA_SAVE;
+\InsetSpace ~
+\InsetSpace ~
+cjne r0,#0,00002$
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+inc __XPAGE
+\newline
+00002$:\InsetSpace ~
+djnz r1,00001$
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+djnz r2,00001$
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+mov __XPAGE,#0
+xFF
+\newline
+00003$:
\end_layout
-\begin_layout Standard
-On other architectures which have seperate opcodes for enabling and disabling
- interrupts you might want to make use of defines with inline assembly
-\begin_inset LatexCommand \index{Assembler routines}
-
-\end_inset
-
- (HC08
-\begin_inset LatexCommand \index{HC08!interrupt}
-
-\end_inset
+\begin_layout Verse
-):
+\family typewriter
+\series bold
+\size footnotesize
+(crtclear.asm)
\end_layout
\begin_layout Verse
\family typewriter
-#define CLI _asm
-\begin_inset LatexCommand \index{\_asm}
-
-\end_inset
-
+\size footnotesize
\InsetSpace ~
\InsetSpace ~
-cli\InsetSpace ~
\InsetSpace ~
-_endasm
-\begin_inset LatexCommand \index{\_endasm}
-
-\end_inset
-
-;
-\end_layout
-
-\begin_layout Verse
-
-\family typewriter
-#define SEI _asm\InsetSpace ~
\InsetSpace ~
-sei\InsetSpace ~
\InsetSpace ~
-_endasm;
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+.area GSINIT4 (CODE)
+\newline
+__mcs51_genRAMCLEAR::
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+clr a
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+mov r0,#(l_IRAM-1)
+\newline
+00004$:\InsetSpace ~
+mov
+ @r0,a
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+djnz r0,00004$
+\newline
+; _mcs51_genRAMCLEAR() end
\end_layout
\begin_layout Verse
\family typewriter
-...
-\end_layout
-
-\begin_layout Standard
-Note: it is sometimes sufficient to disable only a specific interrupt source
- like f.e.
- a timer or serial interrupt by manipulating an
-\emph on
-interrupt mask
-\begin_inset LatexCommand \index{interrupt mask}
-
-\end_inset
-
-
-\emph default
- register.
-
-\end_layout
-
-\begin_layout Standard
-Usually the time during which interrupts are disabled should be kept as
- short as possible.
- This minimizes both
-\emph on
-interrupt latency
-\emph default
-
-\begin_inset LatexCommand \index{interrupt latency}
-
-\end_inset
-
- (the time between the occurrence of the interrupt and the execution of
- the first code in the interrupt routine) and
-\emph on
-interrupt jitter
-\emph default
-
-\begin_inset LatexCommand \index{interrupt jitter}
-
-\end_inset
-
- (the difference between the shortest and the longest interrupt latency).
- These really are something different, f.e.
- a serial interrupt has to be served before its buffer overruns so it cares
- for the maximum interrupt latency, whereas it does not care about jitter.
- On a loudspeaker driven via a digital to analog converter which is fed
- by an interrupt a latency of a few milliseconds might be tolerable, whereas
- a much smaller jitter will be very audible.
-\end_layout
-
-\begin_layout Standard
-You can reenable interrupts within an interrupt routine and on some architecture
-s you can make use of two (or more) levels of
-\emph on
-interrupt priorities
-\emph default
-
-\begin_inset LatexCommand \index{interrupt priority}
-
-\end_inset
-
-.
- On some architectures which don't support interrupt priorities these can
- be implemented by manipulating the interrupt mask and reenabling interrupts
- within the interrupt routine.
- Check there is sufficient space on the stack
-\begin_inset LatexCommand \index{stack}
-
-\end_inset
-
- and don't add complexity unless you have to.
-
-\end_layout
-
-\begin_layout Subsection
-Semaphore
-\begin_inset LatexCommand \index{semaphore}
-
-\end_inset
-
- locking (mcs51/ds390)
+\series bold
+\size footnotesize
+(crtxclear.asm)
\end_layout
-\begin_layout Standard
-Some architectures (mcs51/ds390) have an atomic
-\begin_inset LatexCommand \index{atomic}
-
-\end_inset
-
- bit test and
-\emph on
-
-\emph default
-clear
-\emph on
-
-\emph default
-instruction.
- These type of instructions are typically used in preemptive multitasking
- systems, where a routine f.e.
- claims the use of a data structure ('acquires a lock
-\begin_inset LatexCommand \index{lock}
-
-\end_inset
-
- on it'), makes some modifications and then releases the lock when the data
- structure is consistent again.
- The instruction may also be used if interrupt and non-interrupt code have
- to compete for a resource.
- With the atomic bit test and clear instruction interrupts
-\begin_inset LatexCommand \index{interrupt}
-
-\end_inset
-
- don't have to be disabled for the locking operation.
-
-\end_layout
+\begin_layout Verse
-\begin_layout Standard
-SDCC generates this instruction if the source follows this pattern:
+\family typewriter
+\size footnotesize
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+.area GSINIT4 (CODE)
+\newline
+__mcs51_genXRAMCLEAR::
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+mov r0,#l_PSEG
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+mov a,r0
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+orl a,#(l_PSEG
+ >> 8)
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+jz 00006$
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+mov r1,#s_PSEG
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+mov __XPAGE,#(s_PSEG >> 8)
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+clr a
+\newline
+00005$:\InsetSpace ~
+movx
+ @r1,a
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+inc r1
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+djnz r0,00005$
+\newline
+00006$:
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+mov r0,#l_XSEG
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+mov a,r0
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+orl a,#(l_XSEG >>
+ 8)
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+jz 00008$
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+mov r1,#((l_XSEG + 255) >> 8)
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+mov dptr,#s_XSEG
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+clr a
+\newline
+00007$:\InsetSpace ~
+movx
+ @dptr,a
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+inc dptr
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+djnz r0,00007$
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+djnz r1,00007$
+\newline
+00008$:
\end_layout
\begin_layout Verse
\family typewriter
-volatile
-\begin_inset LatexCommand \index{volatile}
+\series bold
+\size footnotesize
+(crtxstack.asm)
+\end_layout
-\end_inset
+\begin_layout Verse
- bit resource_is_free;
+\family typewriter
+\size footnotesize
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+.area GSINIT5 (CODE)
\newline
-
+; Need to initialize in GSINIT5 because __mcs51_genXINIT
+ modifies __XPAGE
\newline
-if (resource_is_free)
+; and __mcs51_genRAMCLEAR modifies _spx.
\newline
\InsetSpace ~
\InsetSpace ~
-{
-\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-resource_is_free=0;
-\newline
\InsetSpace ~
\InsetSpace ~
+mov __XPAGE,#(__start__x
+stack >> 8)
+\newline
\InsetSpace ~
\InsetSpace ~
-...
-
-\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-resource_is_free=1;
-\newline
\InsetSpace ~
\InsetSpace ~
-}
-\end_layout
-
-\begin_layout Standard
-Note, mcs51 and ds390 support only an atomic
-\begin_inset LatexCommand \index{atomic}
-
-\end_inset
-
- bit test and
-\emph on
-clear
-\emph default
- instruction (as opposed to atomic bit test and
-\emph on
-set).
+mov _spx,#__start__xstack
\end_layout
-\begin_layout Section
-Functions using private register banks
-\begin_inset LatexCommand \label{sub:Functions-using-private-banks}
-
-\end_inset
+\begin_layout Verse
- (mcs51/ds390)
+\family typewriter
+\series bold
+\size footnotesize
+(application modules)
\end_layout
-\begin_layout Standard
-Some architectures have support for quickly changing register sets.
- SDCC supports this feature with the
-\emph on
-using
-\begin_inset LatexCommand \index{using (mcs51, ds390 register bank)}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{\_\_using (mcs51, ds390 register bank)}
-
-\end_inset
-
-
-\emph default
- attribute (which tells the compiler to use a register bank
-\begin_inset LatexCommand \index{register bank (mcs51, ds390)}
-
-\end_inset
-
- other than the default bank zero).
- It should only be applied to
-\emph on
-interrupt
-\begin_inset LatexCommand \index{interrupt}
-
-\end_inset
-
+\begin_layout Verse
-\emph default
- functions (see footnote below).
- This will in most circumstances make the generated ISR code more efficient
- since it will not have to save registers on the stack.
+\family typewriter
+\size footnotesize
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+.area GSINIT (CODE)
\end_layout
-\begin_layout Standard
-The
-\emph on
-using
-\emph default
- attribute will have no effect on the generated code for a
-\emph on
-non-interrupt
-\emph default
- function (but may occasionally be useful anyway
-\begin_inset Foot
-status open
+\begin_layout Verse
-\begin_layout Standard
-possible exception: if a function is called ONLY from 'interrupt' functions
- using a particular bank, it can be declared with the same 'using' attribute
- as the calling 'interrupt' functions.
- For instance, if you have several ISRs using bank one, and all of them
- call memcpy(), it might make sense to create a specialized version of memcpy()
- 'using 1', since this would prevent the ISR from having to save bank zero
- to the stack on entry and switch to bank zero before calling the function
+\family typewriter
+\series bold
+\size footnotesize
+(main.asm)
\end_layout
-\end_inset
+\begin_layout Verse
-).
+\family typewriter
+\size footnotesize
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+.area GSFINAL (CODE)
\newline
-
-\emph on
-(pending: Note, nowadays the
-\emph default
-using
-\emph on
- attribute has an effect on
-\emph default
-
-\emph on
-the generated code for a
-\emph default
-non-interrupt
-\emph on
- function
-\emph default
-.
-\emph on
-)
-\end_layout
-
-\begin_layout Standard
-An
-\emph on
-interrupt
-\emph default
- function using a non-zero bank will assume that it can trash that register
- bank, and will not save it.
- Since high-priority interrupts
-\begin_inset LatexCommand \index{interrupts}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{interrupt priority}
-
-\end_inset
-
- can interrupt low-priority ones on the 8051 and friends, this means that
- if a high-priority ISR
-\emph on
-using
-\emph default
- a particular bank occurs while processing a low-priority ISR
-\emph on
-using
-\emph default
- the same bank, terrible and bad things can happen.
- To prevent this, no single register bank should be
-\emph on
-used
-\emph default
- by both a high priority and a low priority ISR.
- This is probably most easily done by having all high priority ISRs use
- one bank and all low priority ISRs use another.
- If you have an ISR which can change priority at runtime, you're on your
- own: I suggest using the default bank zero and taking the small performance
- hit.
-\end_layout
-
-\begin_layout Standard
-It is most efficient if your ISR calls no other functions.
- If your ISR must call other functions, it is most efficient if those functions
- use the same bank as the ISR (see note 1 below); the next best is if the
- called functions use bank zero.
- It is very inefficient to call a function using a different, non-zero bank
- from an ISR.
-
-\begin_inset VSpace bigskip
-\end_inset
-
-
-\end_layout
-
-\begin_layout Section
-Startup Code
-\begin_inset LatexCommand \label{sub:Startup-Code}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{Startup code}
-
-\end_inset
-
-
-\end_layout
-
-\begin_layout Subsection
-MCS51/DS390 Startup Code
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+ljmp __sdcc_program_startup
+\newline
+;---------------------------------
+-----------------------
+\newline
+; Home
+\newline
+;--------------------------------------------------
+------
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+.area HOME (CODE)
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+.area CSEG (CODE)
+\newline
+__sdcc_program_startup:
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+lcall _main
+\newline
+;
+ return from main will lock up
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+sjmp .
\end_layout
\begin_layout Standard
-The compiler inserts a call to the C routine
+One of these modules (crtstart.asm) contains a call to the C routine
\emph on
_sdcc_external_startup()
\begin_inset LatexCommand \index{\_sdcc\_external\_startup()}
\series bold
\emph default
-
+
\series default
at the start of the CODE area.
- This routine is in the runtime library
+ This routine is also in the runtime library
\begin_inset LatexCommand \index{Runtime library}
\end_inset
-.
- By default this routine returns 0, if this routine returns a non-zero value,
- the static & global variable initialization will be skipped and the function
- main will be invoked.
+ and returns 0 by default.
+ If this routine returns a non-zero value, the static & global variable
+ initialization will be skipped and the function main will be invoked.
Otherwise static & global variables will be initialized before the function
main is invoked.
- You could add a
+ You could add an
\emph on
_sdcc_external_startup()
\emph default
needs to be disabled, this is the place to do it.
The startup code clears all internal data memory, 256 bytes by default,
- but from 0 to n-1 if
+ but from 0 to n-1 if
\emph on
-
\begin_inset ERT
\end_layout
\begin_layout Standard
-See also the compiler options
+See also the compiler options
\emph on
-
\begin_inset ERT
\end_inset
-,
+,
\emph on
-
\begin_inset ERT
\end_inset
- and section
+ and section
\begin_inset LatexCommand \ref{sub:MCS51-variants}
\end_inset
about MCS51-variants.
+\newline
+
+\end_layout
+
+\begin_layout Standard
+While these initialization modules are meant as generic startup code there
+ might be the need for customization.
+ Let's assume the return value of
+\emph on
+_sdcc_external_startup()
+\emph default
+ in
+\emph on
+crtstart.asm
+\emph default
+ should not be checked (or
+\emph on
+_sdcc_external_startup()
+\emph default
+ should not be called at all).
+ The recommended way would be to copy
+\emph on
+crtstart.asm
+\emph default
+ (f.e.
+ from
+\begin_inset LatexCommand \url{http://sdcc.svn.sourceforge.net/viewvc/*checkout*/sdcc/trunk/sdcc/device/lib/mcs51/crtstart.asm}
+
+\end_inset
+
+) into the source directory, adapt it there, then assemble it with
+\emph on
+asx8051 -plosgff
+\begin_inset Foot
+status open
+
+\begin_layout Standard
+\begin_inset Quotes sld
+\end_inset
+
+-plosgff
+\begin_inset Quotes srd
+\end_inset
+
+ are the assembler options used in
+\begin_inset LatexCommand \url{http://sdcc.svn.sourceforge.net/viewvc/sdcc/trunk/sdcc/device/lib/mcs51/Makefile.in?view=markup }
+
+\end_inset
+
+
+\end_layout
+
+\end_inset
+
+ crtstart.asm
+\emph default
+ and when linking your project explicitely specify
+\emph on
+crtstart.rel
+\emph default
+.
+ As a bonus a listing of the relocated object file
+\emph on
+crtstart.rst
+\emph default
+ is generated.
+\end_layout
+
+\begin_layout Standard
\begin_inset VSpace bigskip
\end_inset
the startup code is inserted by linking with crt0.o which is generated from
sdcc/device/lib/z80/crt0.s.
- If you need a different startup code you can use the compiler option
+ If you need a different startup code you can use the compiler option
\emph on
-
\series bold
\end_inset
and provide your own crt0.o.
-
+
\begin_inset VSpace bigskip
\end_inset
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-section
+section
\begin_inset LatexCommand \ref{sub:Common-interrupt-pitfall-volatile}
\end_inset
\newline
\newline
-void to_buffer( unsigned char c )
+void to_buffer( unsigned char c )
\newline
{
\newline
\InsetSpace ~
if( head != (unsigned char)(tail-1)
)\InsetSpace ~
-/* cast
+/* cast
\series bold
needed
\series default
\InsetSpace ~
/* access to a 256 byte aligned array */
\newline
-}
+}
\end_layout
\begin_layout Standard
If the code snippet (assume it is saved in buffer.c) is compiled with SDCC
then a corresponding buffer.asm file is generated.
- We define a new function
+ We define a new function
\family typewriter
to_buffer_asm()
\family default
in file buffer.c in which we cut and paste the generated code, removing
unwanted comments and some ':'.
- Then add
+ Then add
\begin_inset Quotes sld
\end_inset
+
+\series bold
_asm
+\series default
+
\begin_inset Quotes srd
\end_inset
- and
+ and
\begin_inset Quotes sld
\end_inset
+
+\series bold
_endasm;
+\series default
+
\begin_inset Quotes srd
+\end_inset
+
+
+\begin_inset Foot
+status open
+
+\begin_layout Standard
+Note, that the single underscore form (_asm and _endasm) are not C99-compatible,
+ and for C-99 compatibility, the double-underscore form (__asm and __endasm)
+ has to be used.
+ The latter is also used in the library functions.
+\end_layout
+
\end_inset
to the beginning and the end of the function body:
\InsetSpace ~
\InsetSpace ~
The
- function is not yet OK! (registers aren't saved) */
+ function is not yet OK! (registers aren't saved) */
\newline
void to_buffer_asm(
- unsigned char c )
+ unsigned char c )
\newline
-{
+{
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
-r2,dpl
+r2,dpl
\newline
;buffer.c if( head != (unsigned char)(tail-1) ) \InsetSpace ~
-/* cast
+/* cast
\series bold
needed
\series default
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
-a,_tail
+a,_tail
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
dec\InsetSpace ~
\InsetSpace ~
-a
+a
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
-r3,a
+r3,a
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
-a,_head
+a,_head
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-cjne a,ar3,00106$
+cjne a,ar3,00106$
\newline
\InsetSpace ~
\InsetSpace ~
ret
\newline
00106$:
-
+
\newline
;buffer.c buf[ head++ ] = c; /* access to a 256 byte aligned array */
\begin_inset LatexCommand \index{Aligned array}
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
-r3,_head
+r3,_head
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
inc\InsetSpace ~
\InsetSpace ~
-_head
+_head
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
-dpl,r3
+dpl,r3
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
-dph,#(_buf >> 8)
+dph,#(_buf >> 8)
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
-a,r2
+a,r2
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
movx @dptr,a
-
+
\newline
-00103$:
+00103$:
\newline
\InsetSpace ~
\InsetSpace ~
;
\newline
-}
+}
\end_layout
\begin_layout Standard
\InsetSpace ~
\InsetSpace ~
; save used registers here.
-
+
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
; If we were still using r2,r3 we would have to push them here.
-
+
\newline
; if( head != (unsigned char)(tail-1) )
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-; restore used registers here
+; restore used registers here
\newline
\InsetSpace ~
\InsetSpace ~
\end_inset
- or online at
-\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewvc/*checkout*/sdcc/trunk/sdcc/as/doc/asxhtm.html}
+ or online at
+\begin_inset LatexCommand \url{http://sdcc.svn.sourceforge.net/viewvc/*checkout*/sdcc/trunk/sdcc/as/doc/asxhtm.html}
\end_inset
\end_layout
\begin_layout Standard
-The compiler does not do any validation of the code within the
+The compiler does not do any validation of the code within the
\family typewriter
_asm
\begin_inset LatexCommand \index{\_asm}
\end_inset
has to be done manually.
-
+
\end_layout
\begin_layout Standard
.
There are only a few (if any) cases where this option makes sense, it might
cause some unexpected changes in the inline assembler code.
- Please go through the peephole optimizer rules defined in file
+ Please go through the peephole optimizer rules defined in file
\emph on
SDCCpeeph.def
\emph default
\end_layout
\begin_layout Standard
-A special keyword may be associated with a function declaring it as
+A special keyword may be associated with a function declaring it as
\emph on
_naked
\begin_inset LatexCommand \index{\_naked}
\end_inset
.
-
+
\emph default
-The
+The
\emph on
_naked
\emph default
code for that function.
This means that the user is entirely responsible for such things as saving
any registers that may need to be preserved, selecting the proper register
- bank, generating the
+ bank, generating the
\emph on
return
\emph default
\begin_layout Verse
\family typewriter
-Note, this is an
+Note, this is an
\emph on
outdated
\emph default
example, recent versions of SDCC generate
\newline
-the
+the
\emph on
same
\emph default
\end_layout
\begin_layout Standard
-While there is nothing preventing you from writing C code inside a
+While there is nothing preventing you from writing C code inside a
\family typewriter
_naked
\family default
\begin_layout Standard
SDCC allows the use of in-line assembler with a few restrictions regarding
labels.
- In older versions of the compiler all labels defined within inline assembler
- code
-\emph on
-had to be
-\emph default
- of the form
+ All labels defined within inline assembler code have to be of the form
+
\emph on
nnnnn$
\emph default
- where nnnn is a number less than 100 (which implies a limit of utmost 100
- inline assembler labels
+ where nnnnn is a number less than 100 (which implies a limit of utmost
+ 100 inline assembler labels
\emph on
per function
\emph default
)
\noun default
.
-
+\begin_inset Foot
+status open
+
+\begin_layout Standard
+This is a slightly more stringent rule than absolutely necessary, but stays
+ always on the safe side.
+ Labels in the form of nnnnn$ are local labels in the assembler, locality
+ of which is confined within two labels of the standard form.
+ The compiler uses the same form for labels within a function (but starting
+ from nnnnn=00100); and places always a standard label at the beginning
+ of a function, thus limiting the locality of labels within the scope of
+ the function.
+ So, if the inline assembler part would be embedded into C-code, an improperly
+ placed non-local label in the assembler would break up the reference space
+ for labels created by the compiler for the C-code, leading to an assembling
+ error.
+\end_layout
+
+\begin_layout Standard
+The numeric part of local labels does not need to have 5 digits (although
+ this is the form of labels output by the compiler), any valid integer will
+ do.
+ Please refer to the assemblers documentation for further details.
+\end_layout
+
+\end_inset
+
+
\end_layout
\begin_layout Verse
\end_inset
-
+
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-b,#10
+b,#10
\newline
-00001$:
+00001$:
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-b,00001$
+b,00001$
\newline
_endasm
\begin_inset LatexCommand \index{\_endasm}
\end_layout
\begin_layout Standard
-Inline assembler code cannot reference any C-Labels, however it can reference
+Inline assembler code cannot reference any C-labels, however it can reference
labels
\begin_inset LatexCommand \index{Labels}
\begin_layout Verse
\family typewriter
-foo() {
+foo() {
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-/* some c code */
+/* some c code */
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-_asm
+_asm
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-; some assembler code
+; some assembler code
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-ljmp $0003
+ljmp 0003$
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
_endasm;
-
+
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-/* some more c code */
+/* some more c code */
\newline
clabel:\InsetSpace ~
\InsetSpace ~
/* inline assembler cannot reference this
- label */
+ label */
+\begin_inset Foot
+status open
+
+\begin_layout Standard
+Here, the C-label
+\family typewriter
+clabel
+\family default
+ is translated by the compiler into a local label, so the locality of labels
+ within the function is not broken.
+\end_layout
+
+\end_inset
+
+
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-$0003: ;label (can be referenced by inline assembler only)
-
+0003$: ;label (can be referenced by inline assembler only)
\newline
\InsetSpace ~
\InsetSpace ~
\end_inset
- ;
+ ;
\newline
\InsetSpace ~
\InsetSpace ~
\end_layout
\begin_layout Standard
-The compiler always uses the global registers
+The compiler always uses the global registers
\emph on
DPL, DPH
\begin_inset LatexCommand \index{DPTR, DPH, DPL}
\end_inset
-
+
\emph default
and
\emph on
\emph default
- to pass the first parameter to a routine.
- The second parameter onwards is either allocated on the stack (for reentrant
+ to pass the first (non-bit) parameter to a function, and also to pass the
+ return value
+\begin_inset LatexCommand \index{return value}
+
+\end_inset
+
+of function; according to the following scheme: one byte return value in
+
+\emph on
+DPL
+\emph default
+, two byte value in
+\emph on
+DPL
+\emph default
+ (LSB) and
+\emph on
+DPH
+\emph default
+ (MSB).
+ three byte values (generic pointers) in
+\emph on
+DPH
+\emph default
+,
+\emph on
+DPL
+\emph default
+ and
+\emph on
+B
+\emph default
+, and four byte values in
+\emph on
+DPH
+\emph default
+,
+\emph on
+DPL
+\emph default
+,
+\emph on
+ B
+\emph default
+ and
+\emph on
+ACC
+\emph default
+.
+ Generic pointers
+\begin_inset LatexCommand \index{generic pointer}
+
+\end_inset
+
+ contain type of accessed memory in
+\emph on
+B
+\emph default
+:
+\series bold
+0x00
+\series default
+ -- xdata/far,
+\series bold
+0x40
+\series default
+ -- idata/near -- ,
+\series bold
+0x60
+\series default
+ -- pdata,
+\series bold
+0x80
+\series default
+ -- code
+\begin_inset Note Note
+status collapsed
+
+\begin_layout Standard
+This might not be the case of certain memory models (medium???)
+\end_layout
+
+\end_inset
+
+.
+\end_layout
+
+\begin_layout Standard
+The second parameter onwards is either allocated on the stack (for reentrant
routines or if -
\begin_inset ERT
status collapsed
\end_inset
--stack-auto is used) or in data / xdata memory (depending on the memory
- model).
-
+-stack-auto is used) or in data/xdata memory (depending on the memory model).
+\end_layout
+
+\begin_layout Standard
+Bit parameters are passed in a virtual register called 'bits' in bit-addressable
+ space for reentrant functions or allocated directly in bit memory otherwise.
+\end_layout
+
+\begin_layout Standard
+Functions (with two or more parameters or bit parameters) that are called
+ through function pointers
+\begin_inset LatexCommand \index{function pointers}
+
+\end_inset
+
+ must therefor be reentrant so the compiler knows how to pass the parameters.
+\end_layout
+
+\begin_layout Subsection
+Registers usage
+\end_layout
+
+\begin_layout Standard
+Unless the called function is declared as
+\family typewriter
+_naked
+\family default
+
+\begin_inset LatexCommand \index{naked}
+
+\end_inset
+
+, or the -
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-callee-saves
+\begin_inset LatexCommand \index{-\/-callee-saves}
+
+\end_inset
+
+/-
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-all-callee-saves command line option or the corresponding callee_saves
+ pragma are used, the caller will save the registers (
+\emph on
+R0-R7
+\emph default
+) around the call, so the called function can destroy they content freely.
+\end_layout
+
+\begin_layout Standard
+If the called function is not declared as
+\family typewriter
+_naked
+\family default
+, the caller will swap register banks around the call, if caller and callee
+ use different register banks (having them defined by the
+\family typewriter
+_using
+\family default
+ modifier).
+
+\end_layout
+
+\begin_layout Standard
+The called function can also use
+\emph on
+DPL
+\emph default
+,
+\emph on
+DPH
+\emph default
+,
+\emph on
+B
+\emph default
+ and
+\emph on
+ACC
+\emph default
+ observing that they are used for parameter/return value passing.
\end_layout
\begin_layout Subsection
\begin_layout Verse
\family typewriter
-.globl _asm_func_PARM_2
+.globl _asm_func_PARM_2
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-.globl _asm_func
+.globl _asm_func
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-.area OSEG
+.area OSEG
\newline
_asm_func_PARM_2:
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-.ds
- 1
+.ds
+ 1
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-.area CSEG
+.area CSEG
\newline
-_asm_func:
+_asm_func:
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-a,dpl
+a,dpl
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-a,_asm_func_PARM_2
+a,_asm_func_PARM_2
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-dpl,a
+dpl,a
\newline
\InsetSpace ~
\InsetSpace ~
\end_inset
-,#0x00
+,#0x00
\newline
\InsetSpace ~
\InsetSpace ~
ret
\end_layout
-\begin_layout Standard
-Note here that the return values
-\begin_inset LatexCommand \index{return value}
-
-\end_inset
-
- are placed in 'dpl' - One byte return value, 'dpl' LSB & 'dph' MSB for
- two byte values.
- 'dpl', 'dph' and 'b' for three byte values (generic pointers) and 'dpl','dph','
-b' & 'acc' for four byte values.
-\end_layout
-
\begin_layout Standard
The parameter naming convention is _<function_name>_PARM_<n>, where n is
the parameter number starting from 1, and counting from the left.
- The first parameter is passed in
-\begin_inset Quotes eld
-\end_inset
-
-dpl
-\begin_inset Quotes erd
-\end_inset
-
- for a one byte parameter,
-\begin_inset Quotes eld
-\end_inset
-
-dptr
-\begin_inset Quotes erd
-\end_inset
-
- for two bytes,
-\begin_inset Quotes eld
-\end_inset
-
-b,dptr
-\begin_inset Quotes erd
-\end_inset
-
- for three bytes and
-\begin_inset Quotes eld
-\end_inset
-
-acc,b,dptr
-\begin_inset Quotes erd
-\end_inset
-
- for a four bytes parameter.
+ The first parameter is passed in
+\emph on
+DPH
+\emph default
+,
+\emph on
+DPL
+\emph default
+,
+\emph on
+B
+\emph default
+ and
+\emph on
+ACC
+\emph default
+ according to the description above.
The variable name for the second parameter will be _<function_name>_PARM_2.
\newline
onwards will be passed on the stack, the parameters are pushed from right
to left i.e.
- after the call the leftmost parameter will be on the top of the stack.
+ before the call the second leftmost parameter will be on the top of the
+ stack (the leftmost parameter is passed in registers).
Here is an example:
\end_layout
\begin_layout Verse
\family typewriter
-extern int asm_func(unsigned char, unsigned char);
+extern int asm_func(unsigned char, unsigned char, unsigned char) reentrant;
\newline
\newline
-int c_func (unsigned char
- i, unsigned char j) reentrant
+int
+ c_func (unsigned char i, unsigned char j, unsigned char k) reentrant
\newline
-{
+{
+
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-return asm_func(i,j);
+return asm_func(i,j,k);
\newline
-}
+}
\newline
\newline
-int main()
+int main()
\newline
-{
+{
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-return
- c_func(10,9);
+return c_func(10,9,8);
\newline
}
\end_layout
\begin_layout Standard
-The corresponding assembler routine is:
+The corresponding (unoptimized) assembler routine is:
\end_layout
\begin_layout Verse
\family typewriter
-.globl _asm_func
+.globl _asm_func
\newline
-_asm_func:
+_asm_func:
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-push _bp
+push\InsetSpace ~
+_bp
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-mov _bp,sp
+mov\InsetSpace ~
+\InsetSpace ~
+_bp,sp\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+;stack contains: _bp, return
+ address, second parameter, third parameter
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-mov r2,dpl
+mov\InsetSpace ~
+\InsetSpace ~
+r2,dpl
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+mov\InsetSpace ~
+\InsetSpace ~
+a,_bp
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-mov a,_bp
+add\InsetSpace ~
+\InsetSpace ~
+a,#0xfd\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+;calculate
+ pointer to the second parameter
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-add
- a,#0xfd
+mov\InsetSpace ~
+\InsetSpace ~
+r0,a
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-mov r0,a
+mov\InsetSpace ~
+\InsetSpace ~
+a,_bp
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-add a,#0xfc ;?
+add\InsetSpace ~
+\InsetSpace ~
+a,#0xfc\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+;calculate pointer
+ to the rightmost parameter
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-mov r1,a
+mov\InsetSpace ~
+\InsetSpace ~
+r1,a
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-mov a,@r0
+mov\InsetSpace ~
+\InsetSpace ~
+a,@r0
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-add a,r2 ;?
+add\InsetSpace ~
+\InsetSpace ~
+a,@r1
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-mov dpl,a
-
+add\InsetSpace ~
+\InsetSpace ~
+a,r2\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+;calculate the
+ result (= sum of all three parameters)
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-mov dph,#0x00
+mov\InsetSpace ~
+\InsetSpace ~
+dpl,a\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+;return value goes into dptr
+ (cast into int)
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-mov sp,_bp
+mov\InsetSpace ~
+\InsetSpace ~
+dph,#0x00
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-pop _bp
+mov\InsetSpace ~
+\InsetSpace ~
+sp,_bp
+\newline
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+pop\InsetSpace ~
+\InsetSpace ~
+_bp
\newline
\InsetSpace ~
\InsetSpace ~
\begin_inset Text
\begin_layout Standard
-_mulint.c
+_mulint.c
\end_layout
\end_inset
\begin_inset Text
\begin_layout Standard
-_divsint.c
+_divsint.c
\end_layout
\end_inset
\begin_inset Text
\begin_layout Standard
-_divuint.c
+_divuint.c
\end_layout
\end_inset
\begin_inset Text
\begin_layout Standard
-_divslong.c
+_divslong.c
\end_layout
\end_inset
\begin_inset Text
\begin_layout Standard
-_divulong.c
+_divulong.c
\end_layout
\end_inset
\end_layout
\begin_layout Standard
-Since they are compiled as
+Since they are compiled as
\emph on
non-reentrant
\emph default
service routines should not do any of the above operations.
If this is unavoidable then the above routines will need to be compiled
- with the
+ with the
\emph on
-
\begin_inset ERT
\emph default
- option, after which the source program will have to be compiled with
+ option, after which the source program will have to be compiled with
\emph on
-
\begin_inset ERT
\bar no
\noun off
\color none
-Function
+Function
\end_layout
\end_inset
\bar no
\noun off
\color none
-_fssub.c
+_fssub.c
\end_layout
\end_inset
\bar no
\noun off
\color none
-subtract floating point numbers
+subtract floating point numbers
\end_layout
\end_inset
\bar no
\noun off
\color none
-_fsdiv.c
+_fsdiv.c
\end_layout
\end_inset
\bar no
\noun off
\color none
-divide floating point numbers
+divide floating point numbers
\end_layout
\end_inset
\bar no
\noun off
\color none
-_fsmul.c
+_fsmul.c
\end_layout
\end_inset
\bar no
\noun off
\color none
-multiply floating point numbers
+multiply floating point numbers
\end_layout
\end_inset
\emph default
\bar default
\noun default
-\color default
c
\end_layout
not
\emph default
sinf(), cosf(), ...) for the mcs51 are implemented in assembler.
-
+
\end_layout
\end_inset
\end_inset
-As usual on embedded systems you have to provide your own
+As usual on embedded systems you have to provide your own
\family typewriter
getchar()
\begin_inset LatexCommand \index{getchar()}
\end_inset
-
+
\family default
-and
+and
\family typewriter
putchar()
\begin_inset LatexCommand \index{putchar()}
routines.
SDCC does not know whether the system connects to a serial line with or
without handshake, LCD, keyboard or other device.
- And whether a
+ And whether a
\family typewriter
lf
\family default
- to
+ to
\family typewriter
crlf
\family default
- conversion within
+ conversion within
\family typewriter
putchar()
\family default
is intended.
You'll find examples for serial routines f.e.
in sdcc/device/lib.
- For the mcs51 this minimalistic polling
+ For the mcs51 this minimalistic polling
\family typewriter
putchar()
\family default
\begin_layout Verse
\family typewriter
-void putchar (char c) {
+void putchar (char c) {
\newline
\InsetSpace ~
\InsetSpace ~
printf_large.c
\family default
does not support float (except on ds390).
- To enable this recompile it with the option
+ To enable this recompile it with the option
\emph on
-
\begin_inset ERT
\end_layout
\begin_layout Standard
-If you're short on code memory you might want to use
+If you're short on code memory you might want to use
\family typewriter
printf_small()
\begin_inset LatexCommand \index{printf\_small()}
\family default
-
+
\emph on
instead
\emph default
printf().
\family default
- For the mcs51 there additionally are assembly versions
+ For the mcs51 there additionally are assembly versions
\family typewriter
printf_tiny()
\begin_inset LatexCommand \index{printf\_tiny() (mcs51)}
\family default
- (subset of printf using less than 270 bytes) and
+ (subset of printf using less than 270 bytes) and
\family typewriter
printf_fast()
\begin_inset LatexCommand \index{printf\_fast() (mcs51)}
\end_inset
-
+
\family default
and
\family typewriter
\family default
(floating-point aware version of printf_fast) which should fit the requirements
of many embedded systems (printf_fast() can be customized by unsetting
- #defines to
+ #defines to
\emph on
not
\emph default
support long variables and field widths).
- Be shure to only use only one of these printf options within a project.
+ Be sure to use only one of these printf options within a project.
\newline
\end_layout
\begin_layout Standard
-Feature matrix of different
+Feature matrix of different
\emph on
printf
\emph default
\begin_inset Text
\begin_layout Standard
-printf
+printf
\size scriptsize
USE_FLOATS=1
\end_layout
\emph default
\bar default
\noun default
-\color default
f
\family roman
\series medium
\emph off
\bar no
\noun off
-\color none
i
\family default
\series default
\emph on
\bar default
\noun default
-\color default
o
\family roman
\series medium
\emph off
\bar no
\noun off
-\color none
psux
\end_layout
\emph on
\bar default
\noun default
-\color default
o
\family roman
\series medium
\emph off
\bar no
\noun off
-\color none
s
\family default
\series default
\emph default
\bar default
\noun default
-\color default
x
\end_layout
status collapsed
\begin_layout Standard
-Range limited to +/- 4294967040
+Range limited to +/- 4294967040, precision limited to 8 digits past decimal
\end_layout
\end_inset
\begin_layout Standard
0.25 / 0.25 ms
+\begin_inset Foot
+status collapsed
+
+\begin_layout Standard
+printf_tiny integer speed is data dependent, worst case is 0.33 ms
+\end_layout
+
+\end_inset
+
+
\end_layout
\end_inset
\end_inset
-
+
\emph on
LGPL
\emph default
\end_layout
\begin_layout Standard
-\begin_inset Note Comment
+\begin_inset Note Note
status collapsed
\begin_layout Standard
C, CAN, Ethernet, Profibus, Modbus, USB, SPI, JTAG ...), Media (IDE, Memory
cards, eeprom, flash...), En-/Decryption, Remote debugging, Realtime kernel,
- Keyboard, LCD, RTC, FPGA, PID then the sdcc-user mailing list
+ Keyboard, LCD, RTC, FPGA, PID then the sdcc-user mailing list
\begin_inset LatexCommand \url{http://sourceforge.net/mail/?group_id=599}
\end_inset
\end_layout
\begin_layout Standard
-SDCC allows three memory models for MCS51 code,
+SDCC allows three memory models for MCS51 code,
\shape slanted
small, medium
\shape default
- and
+ and
\shape slanted
large
\shape default
.
- Modules compiled with different memory models should
+ Modules compiled with different memory models should
\emph on
never
\emph default
\end_inset
- (see also section
+ (see also section
\begin_inset LatexCommand \ref{sub:MCS51-variants}
\end_inset
-), therefore when using the External Stack option, this port
+), therefore when using the External Stack option, this port
\emph on
may not
\emph default
\newline
Note
that the compiler does not generate any code to place the processor into
- 24 bitmode (although
+ 24 bitmode (although
\emph on
tinibios
\emph default
in the ds390 libraries will do that for you).
- If you don't use
+ If you don't use
\emph on
tinibios
\emph default
\newline
Like
- the
+ the
\emph on
-
\begin_inset ERT
-model-large
\emph default
option, variables will by default be placed into the XDATA segment.
-
+
\newline
\newline
Note that if any segments are located above 64K, the -r flag must be passed
to the linker to generate the proper segment relocations, and the Intel
HEX output format must be used.
- The -r flag can be passed to the linker by using the option
+ The -r flag can be passed to the linker by using the option
\emph on
-Wl-r
\emph default
\end_layout
\begin_layout Standard
-SDCC supports the following #pragma directives:
+Pragmas are used to turn on and/or off certain compiler options.
+ Some of them are closely related to corresponding command-line options
+ (see section
+\begin_inset LatexCommand \vref{sec:Command-Line-Options}
+
+\end_inset
+
+).
+\newline
+Pragmas should be placed before and/or after a function, placing pragmas
+ inside a function body could have unpredictable results.
+\newline
+
+\newline
+SDCC supports the
+ following #pragma directives:
\end_layout
\begin_layout Itemize
\end_inset
- function1[,function2[,function3...]] - The compiler by default uses a caller
- saves convention for register saving across function calls, however this
- can cause unnecessary register pushing & popping
+ function1[,function2[,function3...]]
+\begin_inset LatexCommand \label{ite:callee_saves-function1[,function2[,function3...]]--}
+
+\end_inset
+
+- The compiler by default uses a caller saves convention for register saving
+ across function calls, however this can cause unnecessary register pushing
+ and popping
\begin_inset LatexCommand \index{push/pop}
\end_inset
This option can be used to switch off the register saving convention for
the function names specified.
The compiler will not save registers when calling these functions, extra
- code need to be manually inserted at the entry & exit for these functions
- to save & restore the registers used by these functions, this can SUBSTANTIALLY
- reduce code & improve run time performance of the generated code.
+ code need to be manually inserted at the entry and exit for these functions
+ to save and restore the registers used by these functions, this can SUBSTANTIAL
+LY reduce code and improve run time performance of the generated code.
In the future the compiler (with inter procedural analysis) may be able
to determine the appropriate scheme to use for each function call.
If -
\end_inset
--callee-saves command line option is used, the function names specified
- in #pragma\InsetSpace ~
+-callee-saves command line option is used (see page
+\begin_inset LatexCommand \vpageref{lyx:--callee-saves-function1[,function2][,function3]...}
+
+\end_inset
+
+), the function names specified in #pragma\InsetSpace ~
callee_saves
\begin_inset LatexCommand \index{\#pragma callee\_saves}
\end_inset
- instructions in
+ instructions in
\emph on
I
\emph default
\end_inset
-
+
\emph on
S
\emph default
-ervice
+ervice
\emph on
R
\emph default
less_pedantic
\series default
+\begin_inset LatexCommand \index{pedantic}
+
+\end_inset
+
+
\begin_inset LatexCommand \index{\#pragma less\_pedantic}
\end_inset
- - the compiler will not warn you anymore for obvious mistakes, you'r on
- your own now ;-(
+
+\begin_inset LatexCommand \label{ite:less_pedantic}
+
+\end_inset
+
+- the compiler will not warn you anymore for obvious mistakes, you're on
+ your own now ;-( .
+ See also the command line option -
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-less-pedantic
+\begin_inset LatexCommand \vpageref{lyx:--less-pedantic}
+
+\end_inset
+
+.
+
+\newline
+More specifically, the following warnings will be disabled:
+\shape italic
+comparison is always [true/false] due to limited range of data type
+\shape default
+ (94);
+\shape italic
+overflow in implicit constant conversion
+\shape default
+ (158); [the (in)famous]
+\shape italic
+conditional flow changed by optimizer: so said EVELYN the modified DOG
+\shape default
+ (110);
+\shape italic
+function '[function name]' must return value
+\shape default
+ (59).
+
+\newline
+Furthermore, warnings of less importance (of PEDANTIC and INFO warning
+ level) are disabled, too, namely:
+\shape italic
+constant value '[
+\begin_inset Note Note
+status collapsed
+
+\begin_layout Standard
+dunno what comes here - this warning appears to be unused altogether
+\end_layout
+
+\end_inset
+
+]', out of range
+\shape default
+ (81);
+\shape italic
+[left/right] shifting more than size of object changed to zero
+\shape default
+ (116);
+\shape italic
+unreachable code
+\shape default
+ (126);
+\shape italic
+integer overflow in expression
+\shape default
+ (165);
+\shape italic
+unmatched #pragma save and #pragma restore
+\shape default
+ (170);
+\shape italic
+comparison of 'signed char' with 'unsigned char' requires promotion to int
+\shape default
+ (185);
+\shape italic
+ISO C90 does not support flexible array members
+\shape default
+ (187);
+\shape italic
+extended stack by [number] bytes for compiler temp(s) :in function '[function\InsetSpace ~
+nam
+e]':\InsetSpace ~
+[
+\begin_inset Note Note
+status collapsed
+
+\begin_layout Standard
+appears to be always blank - what was supposed to be here?
+\end_layout
+
+\end_inset
+
+]
+\shape default
+ (114);
+\shape italic
+function '[function name]', # edges [number] , # nodes [number] , cyclomatic
+ complexity [number]
+\shape default
+ (121).
\end_layout
\begin_layout Itemize
table (e.g.
for the autovector feature of the Cypress EZ-USB FX2).
More elegantly this can be achieved by obmitting the optional interrupt
- number after the interrupt keyword, see section
+ number after the interrupt keyword, see section
\begin_inset LatexCommand \ref{sub:Interrupt-Service-Routines}
\end_inset
- will not generate code for boundary value checking, when switch statements
are turned into jump-tables (dangerous).
- For more details see section
+ For more details see section
\begin_inset LatexCommand \ref{sub:'switch'-Statements}
\end_inset
\end_inset
- and section
+ and section
\begin_inset LatexCommand \ref{sec:Parameters-and-Local-Variables}
\end_inset
\series bold
opt_code_speed
\series default
-
+
\begin_inset LatexCommand \index{\#pragma opt\_code\_speed}
\end_inset
\series bold
opt_code_size
\series default
-
+
\begin_inset LatexCommand \index{\#pragma opt\_code\_size}
\end_inset
\series bold
opt_code_balanced
\series default
-
+
\begin_inset LatexCommand \index{\#pragma opt\_code\_balanced}
\end_inset
- The compiler will attempt to generate code that is both compact and fast,
as long as meeting one goal is not a detriment to the other (this is the
default).
-
+
\end_layout
\begin_layout Itemize
\series bold
std_sdcc89
\series default
-
+
\begin_inset LatexCommand \index{\#pragma std\_sdcc89}
\end_inset
\series bold
std_c89
\series default
-
+
\begin_inset LatexCommand \index{\#pragma std\_c89}
\end_inset
\series bold
std_sdcc99
\series default
-
+
\begin_inset LatexCommand \index{\#pragma std\_sdcc99}
\end_inset
\series bold
std_c99
\series default
-
+
\begin_inset LatexCommand \index{\#pragma std\_c99}
\end_inset
pedantic_parse_number
\series default
+\begin_inset LatexCommand \index{pedantic}
+
+\end_inset
+
+
\begin_inset LatexCommand \index{\#pragma pedantic\_parse\_number}
\end_inset
- (+ | -) - Pedantic parse numbers so that situations like 0xfe-LO_B(3) are
- parsed properly and the macro LO_B(3) gets expanded.
+ (+ | -)
+\begin_inset LatexCommand \label{ite:pedantic_parse_number}
+
+\end_inset
+
+- Pedantic parse numbers so that situations like 0xfe-LO_B(3) are parsed
+ properly and the macro LO_B(3) gets expanded.
Default is off.
- Below is an example on how to use this pragma.
+ See also the -
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+-pedantic-parse-number command line option
+\begin_inset LatexCommand \vpageref{lyx:-pedantic-parse-number}
+
+\end_inset
+
+.
+
+\newline
+Below is an example on how to use this pragma.
\emph on
Note: this functionality is not in conformance with standard!
\newline
\newline
-void foo (void)
+void foo (void)
\newline
-{
+{
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
...
-
+
\newline
-}
+}
\newline
\end_layout
\newline
\newline
-#define ROMCALL(x)
+#define ROMCALL(x)
\backslash
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-mov R6_B3, #(x & 0xff)
+mov R6_B3, #(x & 0xff)
\backslash
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-mov R7_B3, #((x >> 8) & 0xff)
+mov R7_B3, #((x >> 8) & 0xff)
\backslash
\newline
\end_layout
\begin_layout Standard
-The pragma's are intended to be used to turn-on or off certain optimizations
- which might cause the compiler to generate extra stack / data space to
- store compiler generated temporary variables.
+Some of the pragmas are intended to be used to turn-on or off certain optimizati
+ons which might cause the compiler to generate extra stack and/or data space
+ to store compiler generated temporary variables.
This usually happens in large functions.
Pragma directives should be used as shown in the following example, they
- are used to control options & optimizations for a given function; pragmas
- should be placed before and/or after a function, placing pragma's inside
- a function body could have unpredictable results.
+ are used to control options and optimizations for a given function.
+
\end_layout
\begin_layout Verse
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-/* save the current settings */
+/* save the current settings */
\newline
#pragma nogcse
\begin_inset LatexCommand \index{\#pragma nogcse}
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-/* turnoff global subexpression elimination */
+/* turnoff global subexpression elimination */
\newline
#pragma noinduction
\begin_inset LatexCommand \index{\#pragma noinduction}
\end_inset
- /* turn off induction optimizations */
+ /* turn off induction optimizations */
\newline
-int foo ()
+int foo ()
\newline
-{
+{
\newline
\InsetSpace ~
\InsetSpace ~
...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
- /* large code */
+ /* large code */
\newline
\InsetSpace ~
\InsetSpace ~
...
-
+
\newline
-}
+}
\newline
#pragma restore
\begin_inset LatexCommand \index{\#pragma restore}
\begin_layout Standard
The compiler will generate a warning message when extra space is allocated.
- It is strongly recommended that the save and restore pragma's be used when
+ It is strongly recommended that the save and restore pragmas be used when
changing options for a function.
\newline
\end_inset
-
+
\end_layout
\end_inset
\begin_inset Text
\begin_layout Standard
-when
+when
\emph on
-
\begin_inset ERT
\begin_inset Text
\begin_layout Standard
-when
+when
\emph on
-
\begin_inset ERT
\begin_inset Text
\begin_layout Standard
-when
+when
\emph on
-
\begin_inset ERT
\begin_inset Text
\begin_layout Standard
-when
+when
\emph on
-
\begin_inset ERT
\begin_inset Text
\begin_layout Standard
-when
+when
\emph on
-
\begin_inset ERT
\end_inset
-
+
\end_layout
\end_inset
\begin_inset Text
\begin_layout Standard
-when
+when
\emph on
-mds390
\emph default
\begin_inset Text
\begin_layout Standard
-when
+when
\emph on
-mds390
\emph default
flavours.
While they might differ considerably in respect to Special Function Registers
the core MCS51 is usually not modified or is kept compatible.
-
+
\end_layout
\begin_layout Subsection
-pdata access by SFR
+pdata access by SFR
\end_layout
\begin_layout Standard
\end_inset
.
- In well-established MCS51 tradition the address of this
+ In well-established MCS51 tradition the address of this
\emph on
sfr
\emph default
\begin_layout Verse
\family typewriter
-__sfr __at (0x92) _XPAGE; /* Cypress EZ-USB family */
+__sfr __at (0x85) _XPAGE; /* Ramtron VRS51 family a.k.a.
+ MPAGE */
\end_layout
\begin_layout Verse
\family typewriter
-__sfr __at (0xaf) _XPAGE; /* some Silicon Labs (Cygnal) chips */
+__sfr __at (0x92) _XPAGE; /* Cypress EZ-USB family, Texas Instruments (Chipcon)
+ a.k.a.
+ MPAGE */
\end_layout
\begin_layout Verse
\family typewriter
-__sfr __at (0xaa) _XPAGE; /* some Silicon Labs (Cygnal) chips */
+__sfr __at (0x91) _XPAGE; /* Infineon (Siemens) C500 family a.k.a.
+ XPAGE */
+\end_layout
+
+\begin_layout Verse
+
+\family typewriter
+__sfr __at (0xaf) _XPAGE; /* some Silicon Labs (Cygnal) chips a.k.a.
+ EMI0CN */
+\end_layout
+
+\begin_layout Verse
+
+\family typewriter
+__sfr __at (0xaa) _XPAGE; /* some Silicon Labs (Cygnal) chips a.k.a.
+ EMI0CN */
\end_layout
\begin_layout Standard
For more exotic implementations further customizations may be needed.
- See section
+ See section
\begin_inset LatexCommand \ref{sub:Startup-Code}
\end_inset
In its built-in ROM library it includes functions to access some of the
features, among them is a TCP stack with IP4 and IP6 support.
Library headers (currently in beta status) and other files are provided
- at
+ at
\size footnotesize
\begin_inset LatexCommand \url{ftp://ftp.dalsemi.com/pub/tini/ds80c400/c_libraries/sdcc/index.html}
\end_inset
.
-
+
\begin_inset VSpace bigskip
\end_inset
\end_inset
.
- The Z80 port is passed through the same
+ The Z80 port is passed through the same
\emph on
regressions tests
\begin_inset LatexCommand \index{Regression test}
\emph default
- (see section
+ (see section
\begin_inset LatexCommand \ref{sec:Quality-control}
\end_inset
\end_layout
\begin_layout Standard
-The HC08 port passes the regression test suite (see section
+The HC08 port passes the regression test suite (see section
\begin_inset LatexCommand \ref{sec:Quality-control}
\end_inset
\end_inset
-\end_layout
-
-\begin_layout Standard
-
\newpage
\end_layout
\begin_layout Section
-The PIC14 port
+The PIC14
+\begin_inset LatexCommand \index{PIC14}
+
+\end_inset
+
+ port
\end_layout
\begin_layout Standard
-The 14bit PIC
+The PIC14 port adds support for Microchip
+\begin_inset LatexCommand \index{Microchip}
+
+\end_inset
+
+
+\begin_inset Formula $^{\text{TM}}$
+\end_inset
+
+ PIC
\begin_inset LatexCommand \index{PIC14}
\end_inset
- port still requires a major effort from the development community.
- However it can work for simple code.
- It passes its (smaller set of) regression tests
-\begin_inset LatexCommand \index{Regression test (PIC14)}
+\begin_inset Formula $^{\text{TM}}$
\end_inset
- in the directory
-\shape italic
-sdcc/src/regression
-\shape default
-.
+ MCUs with 14 bit wide instructions.
+ This port is not yet mature and still lacks many features.
+ However, it can work for simple code.
+\end_layout
+
+\begin_layout Standard
+Currently supported devices include:
+\end_layout
+
+\begin_layout Standard
+12F: 629, 635, 675, 683
+\end_layout
+
+\begin_layout Standard
+16C: 432, 433
+\end_layout
+
+\begin_layout Standard
+16C: 554, 557, 558
+\end_layout
+
+\begin_layout Standard
+16C: 62, 620, 620a, 621, 621a, 622, 622a, 63a, 65b
+\end_layout
+
+\begin_layout Standard
+16C: 71, 710, 711, 715, 717, 72, 73b, 745, 74b, 765, 770, 771, 773, 774,
+ 781, 782
+\end_layout
+
+\begin_layout Standard
+16C: 925, 926
+\end_layout
+
+\begin_layout Standard
+16F: 627, 627a, 628, 628a, 630, 636, 639, 648a, 676, 684, 685, 687, 688,
+ 689, 690
+\end_layout
+
+\begin_layout Standard
+16F: 716, 72, 73, 737, 74, 76, 767, 77, 777, 785
+\end_layout
+
+\begin_layout Standard
+16F: 818, 819, 84, 84a, 87, 870, 871, 872, 873, 873a, 874, 874a, 876, 876a,
+ 877, 877a, 88
+\end_layout
+
+\begin_layout Standard
+16F: 913, 914, 916, 917
+\end_layout
+
+\begin_layout Standard
+An up-to-date list of currently supported devices can be obtained via
+\family typewriter
+sdcc -mpic14 -phelp foo.c
+\family default
+ (foo.c must exist...).
\end_layout
\begin_layout Subsection
-C code and 14bit PIC code page
+PIC Code Pages
\begin_inset LatexCommand \index{code page (pic14)}
\end_inset
- and RAM banks
-\begin_inset LatexCommand \index{RAM bank (pic14)}
+ and Memory Banks
+\begin_inset LatexCommand \index{Memory bank (pic14)}
\end_inset
\begin_layout Standard
The linker organizes allocation for the code page and RAM banks.
It does not have intimate knowledge of the code flow.
- It will put all the code section of a single asm file into a single code
+ It will put all the code section of a single .asm file into a single code
page.
In order to make use of multiple code pages, separate asm files must be
used.
- The compiler treats all functions of a single C file as being in the same
- code page unless it is non static.
+ The compiler assigns all
+\emph on
+static
+\emph default
+ functions of a single .c file into the same code page.
\newline
\newline
-To get the best follow these guide lines:
+To get the best results,
+ follow these guidelines:
\end_layout
\begin_layout Enumerate
Make local functions static, as non static functions require code page selection
overhead.
+\newline
+Due to the way sdcc handles functions, place called functions prior
+ to calling functions in the file wherever possible: Otherwise sdcc will
+ insert unneccessary pagesel directives around the call, believing that
+ the called function is externally defined.
\end_layout
\begin_layout Enumerate
For devices that have multiple code pages it is more efficient to use the
- same number of files as pages, i.e.
- for the 16F877 use 4 separate files and i.e.
- for the 16F874 use 2 separate files.
+ same number of files as pages: Use up to 4 separate .c files for the 16F877,
+ but only 2 files for the 16F874.
This way the linker can put the code for each file into different code
- pages and there's less page selection overhead.
+ pages and there will be less page selection overhead.
\end_layout
\begin_layout Enumerate
- And as for any 8 bit micro (especially for PIC 14 as they have a very simple
- instruction set), use 'unsigned char' whereever possible instead of 'int'.
+And as for any 8 bit micro (especially for PIC14 as they have a very simple
+ instruction set), use `unsigned char' wherever possible instead of `int'.
\end_layout
\begin_layout Subsection
-Creating a device include file
+Adding New Devices to the Port
\end_layout
\begin_layout Standard
-For generating a device include file
-\begin_inset LatexCommand \index{PIC14!Header files}
+Adding support for a new 14
+\begin_inset ERT
+status open
+
+\begin_layout Standard
+
+
+\backslash
+,
+\end_layout
\end_inset
- use the support perl script inc2h.pl kept in directory support/script.
+bit PIC MCU requires the following steps:
+\end_layout
+
+\begin_layout Enumerate
+Create a new device description.
+\newline
+Each device is described in two files: pic16f*.h
+ and pic16f*.c.
+ These files primarily define SFRs, structs to access their bits, and symbolic
+ configuration options.
+ Both files can be generated from gputils' .inc files using the perl script
+
+\family typewriter
+support/scripts/inc2h.pl
+\family default
+.
+ This file also contains further instructions on how to proceed.
+\end_layout
+
+\begin_layout Enumerate
+Copy the .h file into SDCC's include path and either add the .c file to your
+ project or copy it to
+\family typewriter
+device/lib/pic/libdev
+\family default
+.
+ Afterwards, rebuild and install the libraries.
+\end_layout
+
+\begin_layout Enumerate
+Edit pic14devices.txt in SDCC's include path (
+\family typewriter
+device/include/pic/
+\family default
+ in the source tree or
+\family typewriter
+/usr/local/share/sdcc/include/pic
+\family default
+ after installation).
+\newline
+You need to add a device specification here to make
+ the memory layout (code banks, RAM, aliased memory regions, ...) known to
+ the compiler.
+ Probably you can copy and modify an existing entry.
+ The file format is documented at the top of the file.
\end_layout
\begin_layout Subsection
-Interrupt code
+Interrupt Code
\end_layout
\begin_layout Standard
-For the interrupt function, use the keyword '__interrupt'
+For the interrupt function, use the keyword `__interrupt'
\begin_inset LatexCommand \index{PIC14!interrupt}
\end_inset
\end_layout
\begin_layout Subsection
-Linking and assembling
+Linking and Assembling
\end_layout
\begin_layout Standard
\end_inset
gpasm.exe or MPLAB's mpasmwin.exe.
- GPUTILS is available from
+ GPUTILS are available from
\begin_inset LatexCommand \url{http://sourceforge.net/projects/gputils}
\end_inset
.
- For linking you can use either GPUTIL's gplink or MPLAB's mplink.exe.
+ For linking you can use either GPUTILS' gplink or MPLAB's mplink.exe.
If you use MPLAB and an interrupt function then the linker script file
vectors section will need to be enlarged to link with mplink.
\newline
\newline
-Here is a
+Here is a
\family typewriter
Makefile
\family default
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-sdcc -S -V -mpic14 -p16F877 $<
-\newline
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-\InsetSpace ~
-gpasm -c $*.asm
+sdcc -V -mpic14 -p16f877 -c $<
\newline
\newline
-$(PRJ).hex: $(OBJS)
+$(PRJ).hex: $(OBJS)
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-gplink
- -m -s $(PRJ).lkr -o $(PRJ).hex $(OBJS) libsdcc.lib
+gplink -m -s $(PRJ).lkr
+ -o $(PRJ).hex $(OBJS) libsdcc.lib
\end_layout
\begin_layout Standard
-Here is a
+Here is a
\family typewriter
Makefile
\family default
\begin_layout Verse
\family typewriter
-.c.o:
+.c.o:
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-sdcc -S -V -mpic14 -p16F877 $<
+sdcc -S -V -mpic14 -p16f877 $<
\newline
\InsetSpace ~
\InsetSpace ~
\newline
$(PRJ).hex: $(OBJS)
-
+
\newline
\InsetSpace ~
\InsetSpace ~
\end_layout
\begin_layout Subsection
-Command-line options
+Command-Line Options
\end_layout
\begin_layout Standard
-help):
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
-
\begin_inset ERT
status collapsed
\end_inset
--debug-extra
+-debug-xtra
\begin_inset LatexCommand \index{PIC14!Options!-\/-debug-extra}
\end_inset
emit debug info in assembly output
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
-
\begin_inset ERT
status collapsed
disable (slightly faulty) optimization on pCode
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
-
\begin_inset ERT
status collapsed
large shared databank to reduce BANKSEL overhead)
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
-
\begin_inset ERT
status collapsed
\end_layout
\begin_layout Subsection
-The library
+Environment Variables
\end_layout
-\begin_layout Subsubsection
-error: missing definition for symbol
-\begin_inset Quotes sld
-\end_inset
+\begin_layout Standard
+The PIC14 port recognizes the following environment variables:
+\end_layout
-__gptrget1
-\begin_inset Quotes srd
-\end_inset
+\begin_layout Description
+SDCC_PIC14_SPLIT_LOCALS If set and not empty, sdcc will allocate each temporary
+ register (the ones called r0xNNNN) in a section of its own.
+ By default (if this variable is unset), sdcc tries to cluster registers
+ in sections in order to reduce the BANKSEL overhead when accessing them.
+\end_layout
+\begin_layout Subsection
+The Library
+\end_layout
+
+\begin_layout Standard
+The PIC14 library currently only contains support routines required by the
+ compiler to implement multiplication, division, and floating point support.
+ No libc-like replacement is available at the moment, though many of the
+ common sdcc library sources (in
+\family typewriter
+device/lib
+\family default
+) should also compile with the PIC14 port.
+\end_layout
+\begin_layout Subsubsection
+error: missing definition for symbol ``__gptrget1''
\end_layout
\begin_layout Standard
The PIC14 port uses library routines to provide more complex operations
like multiplication, division/modulus and (generic) pointer dereferencing.
In order to add these routines to your project, you must link with PIC14's
-
+
\family typewriter
libsdcc.lib
\family default
.
For single source file projects this is done automatically, more complex
- projects must add
+ projects must add
\family typewriter
libsdcc.lib
\family default
\end_layout
\begin_layout Subsubsection
-Processor mismatch in file
-\begin_inset Quotes sld
-\end_inset
-
-XXX
-\begin_inset Quotes srd
-\end_inset
-
-.
+Processor mismatch in file ``XXX''.
\end_layout
\begin_layout Standard
This warning can usually be ignored due to the very good compatibility amongst
- 14 bit PIC
+ 14
+\begin_inset ERT
+status open
+
+\begin_layout Standard
+
+
+\backslash
+,
+\end_layout
+
+\end_inset
+
+bit PIC
\begin_inset LatexCommand \index{PIC14}
\end_inset
\begin_layout Standard
You might also consider recompiling the library for your specific device
- by changing the ARCH=p16f877 (default target) entry in
+ by changing the ARCH=p16f877 (default target) entry in
\family typewriter
device/lib/pic/Makefile.in
\family default
- and
+ and
\family typewriter
device/lib/pic/Makefile
\family default
to reflect your device.
This might even improve performance for smaller devices as unneccesary
- BANKSELs migth be removed.
+ BANKSELs might be removed.
\end_layout
\begin_layout Subsection
-Known bugs
+Known Bugs
\end_layout
\begin_layout Subsubsection
-initialized data
+Function arguments
\end_layout
\begin_layout Standard
-Currently, data can only be initialized if it resides in the source file
- together with
-\emph on
-main()
-\emph default
-.
- Data in other source files will silently
-\series bold
-not
-\series default
- be initialized.
-\family typewriter
-\size footnotesize
-
-\begin_inset Marginal
-status collapsed
-
-\begin_layout Standard
-
-\series bold
-\InsetSpace ~
-!
+Functions with variable argument lists (like printf) are not yet supported.
+ Similarly, taking the argument of the first argument passed into a function
+ does not work: It is currently passed in WREG and has no address...
\end_layout
-\end_inset
-
+\begin_layout Subsubsection
+Regression tests fail
+\end_layout
+\begin_layout Standard
+Though the small subset of regression tests in src/regression passes, SDCC
+ regression test suite does not, indicating that there are still major bugs
+ in the port.
+ However, many smaller projects have successfully used SDCC in the past...
\end_layout
\begin_layout Standard
+\size footnotesize
+
\newpage
\end_layout
\end_layout
\begin_layout Standard
-The PIC16
-\begin_inset LatexCommand \index{PIC16}
-
-\end_inset
-
- port is the portion of SDCC that is responsible to produce code for the
- Microchip
+The PIC16 port adds support for Microchip
\begin_inset LatexCommand \index{Microchip}
\end_inset
-(TM) microcontrollers with 16 bit core.
- Currently this family of microcontrollers contains the PIC18Fxxx and PIC18Fxxxx.
- Currently supported devices are:
-\end_layout
-
-\begin_layout Standard
-\align center
-\begin_inset Tabular
-<lyxtabular version="3" rows="4" columns="6">
-<features>
-<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" width="0">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\begin_layout Standard
-18F242
-\end_layout
+\begin_inset Formula $^{\text{TM}}$
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
-18F248
-\end_layout
+ PIC
+\begin_inset LatexCommand \index{PIC}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
-18F252
-\end_layout
+\begin_inset Formula $^{\text{TM}}$
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
-18F258
+ MCUs with 16 bit wide instructions.
+ Currently this family of microcontrollers contains the PIC18Fxxx and PIC18Fxxxx
+; devices supported by the port include:
\end_layout
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
\begin_layout Standard
-18F442
+18F: 242, 248, 252, 258, 442, 448, 452, 458
\end_layout
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
\begin_layout Standard
-18F448
+18F: 1220, 1320
\end_layout
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
\begin_layout Standard
-18F452
+18F: 2220, 2221, 2320, 2321, 2331, 2431, 2455, 24j10, 2525, 2550, 25j10,
+ 2620
\end_layout
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
\begin_layout Standard
-18F458
+18F: 4220, 4221, 4320, 4321, 4331, 4431, 4455, 44j10, 4520, 4525, 4550,
+ 45j10, 4620
\end_layout
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
\begin_layout Standard
-18F1220
+18F: 6520, 6620, 6680, 6720
\end_layout
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
\begin_layout Standard
-18F2220
+18F: 8520, 8620, 8680, 8720
\end_layout
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\begin_layout Standard
-18F2550
+\begin_layout Subsection
+Global Options
\end_layout
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
\begin_layout Standard
-18F4331
+PIC16 port supports the standard command line arguments as supposed, with
+ the exception of certain cases that will be mentioned in the following
+ list:
\end_layout
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\begin_layout Description
+-
+\begin_inset ERT
+status collapsed
\begin_layout Standard
-18F4455
-\end_layout
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
-18F6520
+\backslash
+/
\end_layout
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
-18F6620
-\end_layout
+-callee-saves
+\begin_inset LatexCommand \index{PIC16!Options!-\/-callee-saves}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+
+ See -
+\begin_inset ERT
+status collapsed
\begin_layout Standard
-18F6680
-\end_layout
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
-18F6720
+\backslash
+/
\end_layout
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
-18F8520
+-all-callee-saves
\end_layout
-\end_inset
-</cell>
-</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\begin_layout Description
+-
+\begin_inset ERT
+status collapsed
\begin_layout Standard
-18F8620
-\end_layout
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
-18F8680
+\backslash
+/
\end_layout
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
-18F8720
-\end_layout
+-fommit-frame-pointer
+\begin_inset LatexCommand \index{PIC16!Options!-\/-fommit-frame-pointer}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\begin_layout Standard
+ Frame pointer will be omitted when the function uses no local variables.
\end_layout
+\begin_layout Subsection
+Port Specific Options
+\begin_inset LatexCommand \index{Options PIC16}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\begin_layout Standard
\end_layout
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+\begin_layout Standard
+The port specific options appear after the global options in the sdcc -
+\begin_inset ERT
+status collapsed
\begin_layout Standard
-\end_layout
-\end_inset
-</cell>
-</row>
-</lyxtabular>
+\backslash
+/
+\end_layout
\end_inset
-
+-help output.
\end_layout
-\begin_layout Subsection
-Global Options
+\begin_layout Subsubsection
+Code Generation Options
\end_layout
\begin_layout Standard
-PIC16 port supports the standard command line arguments as supposed, with
- the exception of certain cases that will be mentioned in the following
- list:
+These options influence the generated assembler code.
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
-
\begin_inset ERT
status collapsed
\end_inset
--callee-saves
-\begin_inset LatexCommand \index{PIC16!Options!-\/-callee-saves}
+-pstack-model=[model] Used in conjuction with the command above.
+ Defines the stack model to be used, valid stack models are:
+\end_layout
-\end_inset
+\begin_deeper
+\begin_layout List
+\labelwidthstring 00.00.0000
- See -
+\emph on
+small
+\emph default
+ Selects small stack model.
+ 8 bit stack and frame pointers.
+ Supports 256 bytes stack size.
+\end_layout
+
+\begin_layout List
+\labelwidthstring 00.00.0000
+
+\emph on
+large
+\emph default
+ Selects large stack model.
+ 16 bit stack and frame pointers.
+ Supports 65536 bytes stack size.
+\end_layout
+
+\end_deeper
+\begin_layout Description
+-
\begin_inset ERT
status collapsed
\end_inset
--all-callee-saves
+-pno-banksel Do not generate BANKSEL assembler directives.
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
-
\begin_inset ERT
status collapsed
\end_inset
--all-callee-saves
-\begin_inset LatexCommand \index{PIC16!Options!-\/-all-callee-saves}
-
-\end_inset
+-extended Enable extended instruction set/literal offset addressing mode.
+ Use with care!
+\end_layout
- All function arguments are passed on stack by default.
-
-\emph on
-There is no need to specify this in the command line.
+\begin_layout Subsubsection
+Optimization Options
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
-
\begin_inset ERT
status collapsed
\end_inset
--fommit-frame-pointer
-\begin_inset LatexCommand \index{PIC16!Options!-\/-fommit-frame-pointer}
-
-\end_inset
+-obanksel=n Set optimization level for inserting BANKSELs.
+\newline
- Frame pointer will be omitted when the function uses no local variables.
\end_layout
-\begin_layout Subsection
-Port Specific Options
-\begin_inset LatexCommand \index{Options PIC16}
-
-\end_inset
-
-
+\begin_deeper
+\begin_layout List
+\labelwidthstring 00.00.0000
+0 no optimization
\end_layout
-\begin_layout Standard
-The port specific options appear after the global options in the sdcc --help
- output.
+\begin_layout List
+\labelwidthstring 00.00.0000
+1 checks previous used register and if it is the same then does not emit
+ BANKSEL, accounts only for labels.
\end_layout
-\begin_layout Subsubsection
-General Options
-\end_layout
+\begin_layout List
+\labelwidthstring 00.00.0000
+2 tries to check the location of (even different) symbols and removes BANKSELs
+ if they are in the same bank.
-\begin_layout Standard
-General options enable certain port features and optimizations.
+\newline
+
+\emph on
+Important: There might be problems if the linker script has data sections
+ across bank borders!
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\end_deeper
+\begin_layout Description
-
\begin_inset ERT
status collapsed
\end_inset
--pstack-model=[model] Used in conjuction with the command above.
- Defines the stack model to be used, valid stack models are :
-\end_layout
-
-\begin_deeper
-\begin_layout List
-\labelwidthstring 00.00.0000
-
-\emph on
-small
-\emph default
- Selects small stack model.
- 8 bit stack and frame pointers.
- Supports 256 bytes stack size.
-\end_layout
-
-\begin_layout List
-\labelwidthstring 00.00.0000
-
-\emph on
-large
-\emph default
- Selects large stack model.
- 16 bit stack and frame pointers.
- Supports 65536 bytes stack size.
+-denable-peeps Force the usage of peepholes.
+ Use with care.
\end_layout
-\end_deeper
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
-
\begin_inset ERT
status collapsed
\end_inset
--preplace-udata-with=[kword] Replaces the default udata keyword for allocating
- unitialized data variables with [kword].
- Valid keywords are: "udata_acs", "udata_shr", "udata_ovr".
+-optimize-goto Try to use (conditional) BRA instead of GOTO.
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
-
\begin_inset ERT
status collapsed
\end_inset
--ivt-loc <nnnn> positions the Interrupt Vector Table at location <nnnn>.
- Useful for bootloaders.
+-optimize-cmp Try to optimize some compares.
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
-
\begin_inset ERT
status collapsed
\end_inset
--asm= sets the full path and name of an external assembler to call.
+-optimize-df Analyze the dataflow of the generated code and improve it.
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Subsubsection
+Assembling Options
+\end_layout
+
+\begin_layout Description
-
\begin_inset ERT
status collapsed
\end_inset
--link= sets the full path and name of an external linker to call.
+-asm= Sets the full path and name of an external assembler to call.
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
-
\begin_inset ERT
status collapsed
\end_layout
\begin_layout Subsubsection
-Optimization Options
-\end_layout
-
-\begin_layout List
-\labelwidthstring 00.00.0000
--
-\begin_inset ERT
-status collapsed
-
-\begin_layout Standard
-
-
-\backslash
-/
-\end_layout
-
-\end_inset
-
--optimize-goto Try to use (conditional) BRA instead of GOTO
+Linking Options
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
-
\begin_inset ERT
status collapsed
\end_inset
--optimize-cmp Try to optimize some compares.
+-link= Sets the full path and name of an external linker to call.
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
-
\begin_inset ERT
status collapsed
\end_inset
--optimize-df Analyze the dataflow of the generated code and improve it.
+-preplace-udata-with=[kword] Replaces the default udata keyword for allocating
+ unitialized data variables with [kword].
+ Valid keywords are: "udata_acs", "udata_shr", "udata_ovr".
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
-
\begin_inset ERT
status collapsed
\end_inset
--obanksel=nn Set optimization level for inserting BANKSELs.
-\newline
-
-\end_layout
-
-\begin_deeper
-\begin_layout List
-\labelwidthstring 00.00.0000
-0 no optimization
-\end_layout
-
-\begin_layout List
-\labelwidthstring 00.00.0000
-1 checks previous used register and if it is the same then does not emit
- BANKSEL, accounts only for labels.
-\end_layout
-
-\begin_layout List
-\labelwidthstring 00.00.0000
-2 tries to check the location of (even different) symbols and removes BANKSELs
- if they are in the same bank.
-
-\newline
-
+-ivt-loc=n Place the interrupt vector table at address
\emph on
-Important: There might be problems if the linker script has data sections
- across bank borders!
-\end_layout
-
-\end_deeper
-\begin_layout Subsubsection
-Linking Options
+n
+\emph default
+.
+ Useful for bootloaders.
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
-
\begin_inset ERT
status collapsed
\end_inset
--nodefaultlibs do not link default libraries when linking
+-nodefaultlibs Do not link default libraries when linking.
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
-
\begin_inset ERT
status collapsed
\end_inset
--no-crt Don't link the default run-time modules
+-use-crt= Use a custom run-time module instead of the defaults.
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
-
\begin_inset ERT
status collapsed
\end_inset
--use-crt= Use a custom run-time module instead of the defaults.
+-no-crt Don't link the default run-time modules
\end_layout
\begin_layout Subsubsection
Debugging options enable extra debugging information in the output files.
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
-
\begin_inset ERT
status collapsed
, but dumps more information.
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
-
\begin_inset ERT
status collapsed
-debug-ralloc Force register allocator to dump <source>.d file with debugging
information.
- <source> is the name of the file compiled.
+ <source> is the name of the file being compiled.
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
-
\begin_inset ERT
status collapsed
-pcode-verbose Enable pcode debugging information in translation.
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
-
\begin_inset ERT
status collapsed
\end_inset
--denable-peeps Force the usage of peepholes.
- Use with care.
+-calltree Dump call tree in .calltree file.
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
-
\begin_inset ERT
status collapsed
\end_inset
--gstack Trace push/pops for stack pointer overflow
-\end_layout
-
-\begin_layout List
-\labelwidthstring 00.00.0000
--
-\begin_inset ERT
-status collapsed
-
-\begin_layout Standard
-
-
-\backslash
-/
-\end_layout
-
-\end_inset
-
--call-tree dump call tree in .calltree file
+-gstack Trace push/pops for stack pointer overflow.
\end_layout
\begin_layout Subsection
-Enviromental Variables
+Enviroment Variables
\end_layout
\begin_layout Standard
Currently there is only two such variables available:
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
-OPTIMIZE_BITFIELD_POINTER_GET when this variable exists reading of structure
+\begin_layout Description
+OPTIMIZE_BITFIELD_POINTER_GET When this variable exists, reading of structure
bitfields is optimized by directly loading FSR0 with the address of the
bitfield structure.
Normally SDCC will cast the bitfield structure to a bitfield pointer and
then load FSR0.
- This step saves data ram and code space for functions that perform heavy
- use of bitfields.
- (ie.
- 80 bytes of code space are saved when compiling malloc.c with this option).
-
+ This step saves data ram and code space for functions that make heavy use
+ of bitfields.
+ (i.e., 80 bytes of code space are saved when compiling malloc.c with this
+ option).
+
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
-NO_REG_OPT do not perform pCode registers optimization.
+\begin_layout Description
+NO_REG_OPT Do not perform pCode registers optimization.
This should be used for debugging purposes.
- In some where bugs in the pcode optimizer are found, users can benefit
- from temporarily disabling the optimizer until the bug is fixed.
+ If bugs in the pcode optimizer are found, users can benefit from temporarily
+ disabling the optimizer until the bug is fixed.
\end_layout
\begin_layout Subsection
\begin_layout Standard
MCU Identification.
-
+
\emph on
xxxx
\emph default
\begin_layout Standard
MCU Identification.
-
+
\emph on
xxxx
\emph default
\end_layout
\begin_layout Standard
-PIC16
+The PIC16
\begin_inset LatexCommand \index{PIC16}
\end_inset
port currently supports the following pragmas:
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
stack
\begin_inset LatexCommand \index{PIC16!Pragmas!\#pragma stack}
\end_inset
- pragma stack
-\begin_inset LatexCommand \index{PIC16!stack}
-
-\end_inset
-
- forces the code generator to initialize the stack & frame pointers at a
- specific address.
- This is an adhoc solution for cases where no STACK directive is available
+ This forces the code generator to initialize the stack & frame pointers
+ at a specific address.
+ This is an ad hoc solution for cases where no STACK directive is available
in the linker script or gplink is not instructed to create a stack section.
\newline
The
\newline
The format is as follows:
+\newline
+
\end_layout
\begin_layout LyX-Code
#pragma stack bottom_address [stack_size]
+\newline
+
\end_layout
\begin_layout Standard
with deep function nesting or excessive stack usage.
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
code
\begin_inset LatexCommand \index{PIC16!Pragmas!\#pragma code}
\end_inset
- place a function symbol at static FLASH address
+ Force a function to a static FLASH address.
\end_layout
\begin_layout LyX-Code
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
library instructs the linker to use a library module.
\newline
Usage:
\begin_layout Standard
This feature allows for linking with specific libraries withoug having to
explicit name them in the command line.
- Note that the
+ Note that the
\noun on
ignore
\noun default
keyword will reject all modules specified by the library pragma.
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
-udata pragma udata instructs the compiler to emit code so that linker will
- place a variable at a specific memory bank
+\begin_layout Description
+udata The pragma udata instructs the compiler to emit code so that linker
+ will place a variable at a specific memory bank.
\end_layout
\begin_layout LyX-Code
\end_inset
port.
- That file is the
+ That file is the
\series bold
pic18fregs.h
\series default
port depends on are the microcontroller device libraries which contain
the symbol definitions for the microcontroller special function registers.
- These libraries have the format pic18fxxxx.lib, where
+ These libraries have the format pic18fxxxx.lib, where
\emph on
xxxx
\emph default
\end_layout
\begin_layout Standard
-Libraries are created with gplib which is part of the gputils package
+Libraries are created with gplib which is part of the gputils package
\begin_inset LatexCommand \url{http://sourceforge.net/projects/gputils}
\end_inset
\end_layout
\begin_layout Standard
-The steps to compile the pic16 libraries under Linux are:
+The steps to compile the pic16 libraries under Linux and Mac OS X are:
\end_layout
\begin_layout LyX-Code
\begin_layout Standard
There exist a special target to build the I/O libraries.
This target is not automatically build because it will build the I/O library
- for
+ for
\emph on
every
\emph default
supported device.
This way building will take quite a lot of time.
- Users are advised to edit the
+ Users are advised to edit the
\series bold
device/lib/pic16/pics.build
\series default
make lib-io
\end_layout
+\begin_layout Subsection
+Adding New Devices to the Port
+\end_layout
+
+\begin_layout Standard
+Adding support for a new 16
+\begin_inset ERT
+status open
+
+\begin_layout Standard
+
+
+\backslash
+,
+\end_layout
+
+\end_inset
+
+bit PIC MCU requires the following steps:
+\end_layout
+
+\begin_layout Enumerate
+Create picDEVICE.c and picDEVICE.h from pDEVICE.inc using
+\newline
+
+\family typewriter
+perl /path/to/sdcc/support/scripts/inc2h-pic16.pl /path/to/gputils/header/pDEVICE.
+inc
+\end_layout
+
+\begin_layout Enumerate
+
+\family typewriter
+mv picDEVICE.h /path/to/sdcc/device/include/pic16
+\end_layout
+
+\begin_layout Enumerate
+
+\family typewriter
+mv picDEVICE.c /path/to/sdcc/device/lib/pic16/libdev
+\end_layout
+
+\begin_layout Enumerate
+Add DEVICE to
+\family typewriter
+/path/to/sdcc/device/lib/pic16/pics.all
+\family default
+ (and
+\family typewriter
+.build
+\family default
+).
+\newline
+Note: No 18f prefix here!
+\end_layout
+
+\begin_layout Enumerate
+Adjust
+\family typewriter
+/path/to/sdcc/device/lib/pic16/libio/*.ignore
+\family default
+
+\newline
+Add your DEVICE if it does not compile in
+\family typewriter
+adc
+\family default
+,
+\family typewriter
+i2c
+\family default
+, or
+\family typewriter
+usart
+\family default
+.
+\end_layout
+
+\begin_layout Enumerate
+Edit
+\family typewriter
+/path/to/sdcc/device/include/pic16/pic18fregs.h
+\family default
+.
+ The file format is self-explanatory, just add
+\newline
+
+\family typewriter
+#elif defined(picDEVICE)
+\newline
+# include <picDEVICE.h>
+\family default
+
+\newline
+at the right place (keep it sorted).
+\end_layout
+
+\begin_layout Enumerate
+Edit
+\family typewriter
+/path/to/sdcc/src/pic16/devices.inc
+\family default
+.
+ Copy and modify an existing entry and insert it at the correct place (keep
+ the file sorted).
+ The file is hardly documented, look at the entries for the 18f2221...
+\end_layout
+
+\begin_layout Enumerate
+Recompile SDCC, including the pic16 libraries.
+\end_layout
+
\begin_layout Subsection
Memory Models
\end_layout
It is advisable that all sources within a project are compiled with the
same memory model.
If one wants to override the default memory model, this can be done by
- declaring a pointer as
+ declaring a pointer as
\series bold
far
\series default
- or
+ or
\series bold
near
\series default
\end_layout
\begin_layout Standard
-The standard device libraries (see
+The standard device libraries (see
\begin_inset LatexCommand \ref{sub:PIC16_Header-Files}
\end_inset
FSR2.
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
FSR1 is assigned as stack pointer
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
FSR2 is assigned as frame pointer
\end_layout
Small
\noun default
model means that only the FSRxL byte is used to access stack and frame,
- while
+ while
\emph on
\noun on
large
\begin_layout Standard
\noun on
-Large
+Large
\noun default
stack model is currently not working properly throughout the code generator.
So its use is not advised.
port makes available two more:
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
wparam
\begin_inset LatexCommand \index{PIC16!wparam}
}
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
shadowregs
\begin_inset LatexCommand \index{PIC16!shadowregs}
When entering/exiting an ISR, it is possible to take advantage of the PIC18F
hardware shadow registers which hold the values of WREG, STATUS and BSR
registers.
- This can be done by adding the keyword
+ This can be done by adding the keyword
\emph on
shadowregs
\emph default
- before the
+ before the
\emph on
interrupt
\emph default
\end_inset
- service routine (ISR) is declared using the
+ service routine (ISR) is declared using the
\emph on
interrupt
\emph default
\end_layout
\begin_layout LyX-Code
-void isr(void) interrupt
+void isr(void) interrupt
\emph on
n
\end_layout
\end_layout
\begin_layout Standard
-When generating assembly code for ISR the code generator places a
+When generating assembly code for ISR the code generator places a
\noun on
-goto
+goto
\noun default
-instruction at the
+instruction at the
\emph on
Interrupt Vector Address
\emph default
which points at the genetated ISR.
- This single GOTO instruction is part of an automatically generated
+ This single GOTO instruction is part of an automatically generated
\emph on
interrupt entry point
\emph default
The actuall ISR code is placed as normally would in the code space.
Upon interrupt request, the GOTO instruction is executed which jumps to
the ISR code.
- When declaring interrupt functions as _naked this GOTO instruction is
+ When declaring interrupt functions as _naked this GOTO instruction is
\series bold
not
\series default
Address of the specific interrupt.
This is not a problem for the LOW priority interrupts, but it is a problem
for the RESET and the HIGH priority interrupts because code may be written
- at the next interrupt´s vector address and cause undeterminate program
+ at the next interrupt's vector address and cause undeterminate program
behaviour if that interrupt is raised.
\begin_inset Foot
status open
\end_layout
\begin_layout Enumerate
-this is a HIGH interrupt ISR and LOW interrupts are
+this is a HIGH interrupt ISR and LOW interrupts are
\emph on
disabled
\emph default
\end_layout
\begin_layout Enumerate
-when the ISR is small enough not to reach the next interrupt´s vector address.
+when the ISR is small enough not to reach the next interrupt's vector address.
\end_layout
\end_inset
\emph on
n
\emph default
- is possible to be omitted.
+ may be omitted.
This way a function is generated similar to an ISR, but it is not assigned
to any interrupt.
\end_layout
\begin_inset Text
\begin_layout Standard
-data
+data
\end_layout
\end_inset
\end_layout
\begin_layout Standard
-In the
+In the
\emph on
stdio.h
\emph default
\begin_layout Standard
The FILE type is actually a generic pointer which defines one more type
- of generic pointers, the
+ of generic pointers, the
\emph on
-stream
+stream
\emph default
pointer.
This new type has the format:
These are
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
_
\begin_inset ERT
status collapsed
_stream_usart_putchar writes a character at the USART stream
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
_
\begin_inset ERT
status collapsed
_stream_mssp_putchar writes a character at the MSSP stream
\end_layout
-\begin_layout List
-\labelwidthstring 00.00.0000
+\begin_layout Description
putchar dummy function.
This writes a character to a user specified manner.
\end_layout
\begin_layout Standard
-In order to increase performance
+In order to increase performance
\emph on
-putchar
+putchar
\emph default
is declared in stdio.h as having its parameter in WREG (it has the wparam
keyword).
In stdio.h exists the macro PUTCHAR(arg) that defines the putchar function
in a user-friendly way.
-
+
\emph on
arg
\emph default
\end_layout
\begin_layout LyX-Code
-}
+}
\newline
\newline
\end_layout
\begin_layout LyX-Code
- printf (¨This is a printf test
+ printf (
+\begin_inset Quotes sld
+\end_inset
+
+This is a printf test
\backslash
-n¨);
+n
+\begin_inset Quotes srd
+\end_inset
+
+);
\end_layout
\begin_layout LyX-Code
\end_layout
\begin_layout Standard
-For sprintf and vsprintf
+For sprintf and vsprintf
\emph on
-buf
+buf
\emph default
should normally be a data pointer where the resulting string will be placed.
No range checking is done so the user should allocate the necessery buffer.
- For fprintf and vfprintf
+ For fprintf and vfprintf
\emph on
fp
\emph default
\end_layout
\begin_layout Standard
-The prototypes for these names are defined in the header file
+The prototypes for these names are defined in the header file
\emph on
signal.h
\emph default
\labelwidthstring 00.00.0000
DEF_INTHIGH(name) begin the definition of the interrupt dispatch table for
high priority interrupts.
-
+
\emph on
name
\emph default
\labelwidthstring 00.00.0000
DEF_INTLOW(name) begin the definition of the interrupt dispatch table fo
low priority interrupt.
-
+
\emph on
name
\emph default
\begin_layout List
\labelwidthstring 00.00.0000
-DEF_HANDLER(sig,handler) define a handler for signal
+DEF_HANDLER(sig,handler) define a handler for signal
\emph on
sig.
\end_layout
\labelwidthstring 00.00.0000
\series medium
-SIGHANDLER(handler)
+SIGHANDLER(handler)
\series default
-this declares the function prototype for the
+this declares the function prototype for the
\emph on
handler
\emph default
\end_layout
\begin_layout Itemize
-when declaring SIGHANDLERNAKED handler never forget to use
+when declaring SIGHANDLERNAKED handler never forget to use
\emph on
retfie
\emph default
\end_layout
\begin_layout Subsection
-Known bugs
+Known Bugs
\end_layout
\begin_layout Standard
\end_inset
- suite (see section
+ suite (see section
\begin_inset LatexCommand \ref{sec:Quality-control}
\end_inset
-) and thus the nightly regression tests for the PIC16 target are currently
- disabled for all hosts except for
+) and thus the snapshot build regression tests for the PIC16 target are
+ currently disabled for all hosts
\emph on
-Linux on Opteron.
-
-\emph default
- This means you can see the result of the PIC16 regression tests f.e.
- by checking the log files in
-\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/regression_test_results/amd64-unknown-linux2.3/}
-
-\end_inset
-
- (pick the most up to date file there, scroll down, lend a hand).
+.
\end_layout
\begin_layout Chapter
\end_inset
--more-pedantic
+-more-pedantic
\begin_inset LatexCommand \ref{lyx:more-pedantic-SPLINT}
\end_inset
\end_inset
--more-pedantic
+-more-pedantic
\begin_inset LatexCommand \ref{lyx:more-pedantic-SPLINT}
\end_inset
- ) on howto handle syntax extensions like __xdata, __at(), ...
-
+) on how to handle syntax extensions like __xdata, __at(), ...
+
\end_layout
\begin_layout Itemize
\end_layout
\begin_layout Itemize
-there is a separate section about SDCDB (section
+there is a separate section about SDCDB (section
\begin_inset LatexCommand \ref{cha:Debugging-with-SDCDB}
\end_inset
\end_inset
- file (see
+ file (see
\begin_inset LatexCommand \ref{OMF file}
\end_inset
\end_layout
\begin_layout Standard
-Debugging On-target:
+Debugging On-target:
\end_layout
\begin_layout Itemize
via a serial line and allows to set program counter, to single step through
a program and read/write memory locations.
For the 8051 good examples of monitors are paulmon and cmon51 (see section
-
+
\begin_inset LatexCommand \ref{sec:Related-open-source-tools}
\end_inset
\begin_layout Itemize
toggle MCU port pins at strategic points within your code and use an oscilloscop
e.
- A
+ A
\emph on
digital oscilloscope
\emph default
resistor to the oscilloscope probe (check output drive capability of the
pins you want to monitor).
- If you need to monitor many more pins a
+ If you need to monitor many more pins a
\emph on
logic analyzer
\emph default
\emph on
i
\emph default
-n
+n
\emph on
c
\emph default
-ircuit
+ircuit
\emph on
e
\emph default
Usually very expensive.
And very nice to have too.
And usually locks you (for years...) to the devices the ICE can emulate.
-
+
\end_layout
\begin_layout Itemize
and a complete debugger is too bulky for the target system.
Therefore usually a debugger on the host system connects to an on-target
debugging stub which accepts only primitive commands.
-
+
\newline
Terms to enter into your favourite search engine could be 'remote debugging',
'gdb stub' or 'inferior debugger'.
Some of the more modern MCUs include hardware support for setting break
points and monitoring/changing variables by using dedicated hardware pins.
This facility doesn't require additional code to run on the target and
-
+
\emph on
usually
\emph default
\end_inset
- file (see
+ file (see
\begin_inset LatexCommand \ref{OMF file}
\end_inset
) as input file.
-
+
\end_layout
\begin_layout Standard
\begin_layout Itemize
if you are not familiar with any of the following terms you're likely to
- run into problems rather sooner than later:
+ run into problems rather sooner than later:
\emph on
volatile
\emph default
-,
+,
\emph on
atomic
\emph default
-,
+,
\emph on
memory map
\emph default
-,
+,
\emph on
overlay
\emph default
.
- As an embedded programmer you
+ As an embedded programmer you
\emph on
have
\emph default
- to know them so why not look them up
+ to know them so why not look them up
\emph on
before
\emph default
\end_inset
-
+
\end_layout
\begin_layout Standard
execution is controlled by the debugger.
When a command is issued for the debugger, it translates it into appropriate
commands for the simulator.
- (Currently SDCDM only connects to the simulator but
+ (Currently SDCDM only connects to the simulator but
\emph on
newcdb
\emph default
- at
+ at
\begin_inset LatexCommand \url{http://ec2drv.sf.net/}
\end_inset
- is an effort to connect directly to the hardware.)
+ is an effort to connect directly to the hardware.)
\end_layout
\begin_layout Subsection
-directory=/home/src1:/home/src2.
Note there can be no spaces in the option.
-
+
\end_layout
\begin_layout Itemize
\family sans
\series bold
-sdcdb>break 100
+sdcdb>break 100
\newline
sdcdb>break foo.c:100
\newline
\end_layout
\begin_layout Subsubsection*
-ptype variable
+ptype variable
\end_layout
\begin_layout Standard
\end_layout
\begin_layout Standard
-\begin_inset Note Comment
+\begin_inset Note Note
status collapsed
\begin_layout Standard
-The screenshot was converted from png to eps with:
+The screenshot was converted from png to eps with:
\begin_inset Quotes sld
\end_inset
\end_layout
\begin_layout Standard
-The
+The
\emph on
p
\emph default
-ortable
+ortable
\emph on
n
\emph default
-etwork
+etwork
\emph on
g
\emph default
-raphics File
+raphics File
\size footnotesize
-\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewcvs.cgi/*checkout*/sdcc/trunk/sdcc/doc/figures/ddd_example.png}
+\begin_inset LatexCommand \url{http://sdcc.svn.sourceforge.net/viewvc/*checkout*/sdcc/trunk/sdcc/doc/figures/ddd_example.png}
\end_inset
The debugging session might not run as smoothly as the screenshot suggests.
The debugger allows setting of breakpoints, displaying and changing variables,
single stepping through C and assembler code.
-
+
\newline
-The source was compiled with
+The source was compiled with
\family sans
\series bold
-debug ddd_example.c
\family default
\series default
-
+
\family sans
\series bold
\series default
\newline
-and DDD was invoked with
+and DDD was invoked with
\family sans
\series bold
ion is complete.
These files need to be loaded into XEmacs for the interface to work.
This can be done at XEmacs startup time by inserting the following into
- your '.xemacs' file (which can be found in your HOME directory):
+ your '.xemacs' file (which can be found in your HOME directory):
\newline
\newline
\family typewriter
-(load-file sdcdbsrc.el)
+(load-file sdcdbsrc.el)
\family default
\newline
The files can also be loaded dynamically while XEmacs is running, set the
environment variable 'EMACSLOADPATH' to the installation bin directory
(<installdir>/bin), then enter the following command ESC-x load-file sdcdbsrc.
- To start the interface enter the following command:
+ To start the interface enter the following command:
\newline
\newline
\newline
You will prompted to enter the file name to be debugged.
-
+
\newline
\newline
\newline
;;\InsetSpace ~
-Current Listing ::
+Current Listing ::
\newline
;;key\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-Comment
+Comment
\newline
;;---\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-------
\newline
-;;
+;;
\newline
;;\InsetSpace ~
n\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-SDCDB next command
+SDCDB next command
\newline
;;\InsetSpace ~
b\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-SDCDB back command
+SDCDB back command
\newline
;;\InsetSpace ~
c\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-SDCDB step command
+SDCDB step command
\newline
;;\InsetSpace ~
?\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-SDCDB ptypecommand for data at
+SDCDB ptypecommand for data at
\newline
;;\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-buffer point
+buffer point
\newline
;;\InsetSpace ~
x\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
SDCD
-B Delete all breakpoints if no arg
+B Delete all breakpoints if no arg
\newline
;;\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-given or delete arg (C-u arg x)
+given or delete arg (C-u arg x)
\newline
;;\InsetSpace ~
m\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-SDCDB Display current frame if no arg,
+SDCDB Display current frame if no arg,
\newline
;;\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
given or display frame arg
-
+
\newline
;;\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-buffer point
+buffer point
\newline
;;\InsetSpace ~
!\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-Goto the SDCDB output buffer
+Goto the SDCDB output buffer
\newline
;;\InsetSpace ~
p\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-SDCDB print command for data at
+SDCDB print command for data at
\newline
;;\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-buffer point
+buffer point
\newline
;;\InsetSpace ~
g\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
Got
-o the SDCDB output buffer
+o the SDCDB output buffer
\newline
;;\InsetSpace ~
t\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
Toggles Sdcdbsrc mode (turns it
- off)
+ off)
\newline
-;;
+;;
\newline
;;\InsetSpace ~
C-c\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-SDCDB finish command
+SDCDB finish command
\newline
-;;
+;;
\newline
;;\InsetSpace ~
C-x\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-Set break for line with point
+Set break for line with point
\newline
;;\InsetSpace ~
ESC\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-Toggle Sdcdbsrc mode
+Toggle Sdcdbsrc mode
\newline
;;\InsetSpace ~
ESC\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-Toggle list mode
+Toggle list mode
\newline
-;;
+;;
\newline
-\end_layout
-
-\begin_layout Standard
+\family default
\newpage
\family typewriter
uc * uc
\family default
- is evaluated as
+ is evaluated as
\family typewriter
(int) uc * (int) uc = (int) 0xfe * (int) 0xfe = (int) 0xfc04 = -1024
\family default
.
-
+
\newline
Another one:
\end_layout
gcc uses 32 bit ints, while SDCC uses 16 bit ints.
Therefore the results are different.
\newline
-From
+From
\begin_inset Quotes sld
\end_inset
\end_layout
\begin_layout Itemize
-Have a look at the assembly listing to get a
+Have a look at the assembly listing to get a
\begin_inset Quotes sld
\end_inset
\end_inset
->
-\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewvc/sdcc/trunk/sdcc/device/include/mcs51/compiler.h?view=markup}
+>
+\begin_inset LatexCommand \url{http://sdcc.svn.sourceforge.net/viewvc/sdcc/trunk/sdcc/device/include/mcs51/compiler.h?view=markup}
\end_inset
to allow using common header files.
(see f.e.
- cc2510fx.h
-\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewvc/sdcc/trunk/sdcc/device/include/mcs51/cc2510fx.h?view=markup}
+ cc2510fx.h
+\begin_inset LatexCommand \url{http://sdcc.svn.sourceforge.net/viewvc/sdcc/trunk/sdcc/device/include/mcs51/cc2510fx.h?view=markup}
\end_inset
\emph on
first
\emph default
- and
+ and
\emph on
last
\emph default
relate to time and not to lower/upper memory location here, so this is
-
+
\emph on
not
\emph default
\end_layout
\begin_layout Itemize
-check whether the keyword
+check whether the keyword
\emph on
volatile
\emph default
The compilers might differ in their optimization characteristics (as different
versions of the same compiler might also use more clever optimizations
this is good idea anyway).
- See section
+ See section
\begin_inset LatexCommand \ref{sub:Common-interrupt-pitfall-volatile}
\end_inset
\begin_layout Itemize
check for differences in type promotion.
- Especially check for math operations on
+ Especially check for math operations on
\family typewriter
char
\family default
- or
+ or
\family typewriter
unsigned char
\family default
variables.
- For the sake of C99 compatibility SDCC will probably promote these to
+ For the sake of C99 compatibility SDCC will probably promote these to
\family typewriter
int
\family default
more often than other compilers.
- Eventually insert explicit casts to
+ Eventually insert explicit casts to
\family typewriter
-(char)
+(char)
\family default
or
\family typewriter
\end_inset
- is not used on
+ is not used on
\family typewriter
bit
\begin_inset LatexCommand \index{bit}
\family default
variables, use the !\InsetSpace ~
operator instead.
- See sections
+ See sections
\begin_inset LatexCommand \ref{type promotion}
\end_inset
- and
+ and
\begin_inset LatexCommand \ref{sec:Compatibility-with-previous}
\end_inset
\end_inset
-) char variables as
+) char variables as
\family typewriter
int
\family default
- others push them as
+ others push them as
\family typewriter
char
\family default
.
- See section
+ See section
\begin_inset LatexCommand \ref{sec:Compatibility-with-previous}
\end_inset
\begin_inset Text
\begin_layout Standard
-Intel Hex packer
+Intel Hex packer
\begin_inset LatexCommand \index{packihx (tool)}
\end_inset
\newline
-\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewvc/*checkout*/sdcc/trunk/sdcc/ChangeLog}
+\begin_inset LatexCommand \url{http://sdcc.svn.sourceforge.net/viewvc/*checkout*/sdcc/trunk/sdcc/ChangeLog}
\end_inset
\begin_inset Text
\begin_layout Standard
-sdcc/as/doc/asxhtm.html
+sdcc/as/doc/asxhtm.html
\emph on
\InsetSpace ~
\InsetSpace ~
\newline
-\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewvc/*checkout*/sdcc/trunk/sdcc/as/doc/asxhtm.html}
+\begin_inset LatexCommand \url{http://sdcc.svn.sourceforge.net/viewvc/*checkout*/sdcc/trunk/sdcc/as/doc/asxhtm.html}
\end_inset
\begin_inset Text
\begin_layout Standard
-sdcc/doc/test_suite_spec.pdf
+sdcc/doc/test_suite_spec.pdf
\emph on
\InsetSpace ~
\InsetSpace ~
\begin_inset Text
\begin_layout Standard
-sdcc/doc/*
+sdcc/doc/*
\emph on
\InsetSpace ~
\InsetSpace ~
\newline
-\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewvc/sdcc/trunk/sdcc/doc/}
+\begin_inset LatexCommand \url{http://sdcc.svn.sourceforge.net/viewvc/sdcc/trunk/sdcc/doc/}
\end_inset
\begin_inset Text
\begin_layout Standard
-sdcc/debugger/README
+sdcc/debugger/README
\emph on
\InsetSpace ~
\InsetSpace ~
:
\newline
-\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewvc/*checkout*/sdcc/trunk/sdcc/debugger/README}
+\begin_inset LatexCommand \url{http://sdcc.svn.sourceforge.net/viewvc/*checkout*/sdcc/trunk/sdcc/debugger/README}
\end_inset
\emph default
\bar default
\noun default
-\color default
-/index.html
+/index.html
\emph on
\InsetSpace ~
\InsetSpace ~
\newline
-\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewvc/*checkout*/sdcc/trunk/sdcc/sim/ucsim/doc/index.html}
+\begin_inset LatexCommand \url{http://sdcc.svn.sourceforge.net/viewvc/*checkout*/sdcc/trunk/sdcc/sim/ucsim/doc/index.html}
\end_inset
\begin_inset Text
\begin_layout Standard
-sdcc/src/pic16/NOTES
+sdcc/src/pic16/NOTES
\emph on
\InsetSpace ~
\InsetSpace ~
\emph default
-\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewvc/*checkout*/sdcc/trunk/sdcc/src/pic16/NOTES}
+\begin_inset LatexCommand \url{http://sdcc.svn.sourceforge.net/viewvc/*checkout*/sdcc/trunk/sdcc/src/pic16/NOTES}
\end_inset
\emph default
\bar default
\noun default
-\color default
f
\emph on
\InsetSpace ~
\begin_layout Standard
\align left
\begin_inset Tabular
-<lyxtabular version="3" rows="14" columns="3">
+<lyxtabular version="3" rows="16" columns="3">
<features>
<column alignment="left" valignment="top" leftline="true" width="0pt">
<column alignment="block" valignment="top" leftline="true" width="30line%">
-<column alignment="left" valignment="top" leftline="true" rightline="true" width="0pt">
+<column alignment="left" valignment="top" leftline="true" rightline="true" width="40col%">
<row topline="true" bottomline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\begin_inset Text
\begin_layout Standard
-Statically checks c sources (see
+Statically checks c sources (see
\begin_inset LatexCommand \ref{lyx:more-pedantic-SPLINT}
\end_inset
\end_inset
+\end_layout
+
+\end_inset
+</cell>
+</row>
+<row bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+d52
+\begin_inset LatexCommand \index{d52}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{d52 (disassembler)}
+
+\end_inset
+
+
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+Disassembler, can count instruction cycles
+\begin_inset LatexCommand \index{instruction cycles (count)}
+
+\end_inset
+
+, use with options -pnd
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+\begin_inset LatexCommand \url{http://www.8052.com/users/disasm/}
+
+\end_inset
+
+
+\end_layout
+
+\end_inset
+</cell>
+</row>
+<row bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+cmake
+\begin_inset LatexCommand \index{cmake}
+
+\end_inset
+
+
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+Cross platform build system, generates Makefiles
+\begin_inset LatexCommand \index{Makefile}
+
+\end_inset
+
+ and project workspaces
+\begin_inset LatexCommand \index{project workspace}
+
+\end_inset
+
+
+\end_layout
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\begin_layout Standard
+\begin_inset LatexCommand \url{http://www.cmake.org}
+
+\end_inset
+
+ \InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+\InsetSpace ~
+and a dedicated wiki entry:
+\begin_inset LatexCommand \url{http://www.cmake.org/Wiki/CmakeSdcc}
+
+\end_inset
+
+
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-Installing and Configuring SDCC and Crimson Editor
+Installing and Configuring SDCC and Crimson Editor
\end_layout
\end_inset
\begin_layout Standard
Some questions answered, some pointers given - it might be time to in turn
- ask
+ ask
\emph on
you
\emph default
- some questions:
+ some questions:
\end_layout
\begin_layout Itemize
\begin_layout Standard
Maybe not all answers to these questions are known and some answers may
- even be
+ even be
\emph on
no
\emph default
You can help by reporting the bugs and helping other SDCC users.
There are lots of ways to contribute, and we encourage you to take part
in making SDCC a great software package.
-
+
\end_layout
\begin_layout Standard
-The SDCC project is hosted on the SDCC sourceforge site at
+The SDCC project is hosted on the SDCC sourceforge site at
\begin_inset LatexCommand \htmlurl{http://sourceforge.net/projects/sdcc}
\end_inset
\begin_layout Enumerate
Attach the code you are compiling with SDCC.
-
+
\end_layout
\begin_layout Enumerate
Specify the exact command you use to run SDCC, or attach your Makefile.
-
+
\end_layout
\begin_layout Enumerate
\family default
\series default
"), your platform, and operating system.
-
+
\end_layout
\begin_layout Enumerate
Provide an exact copy of any error message or incorrect output.
-
+
\end_layout
\begin_layout Enumerate
chance that SDCC users and developers will be able to help you.
Some SDCC developers are frustrated by bug reports without code provided
that they can use to reproduce and ultimately fix the problem, so please
- be sure to provide sample code if you are reporting a bug!
+ be sure to provide sample code if you are reporting a bug!
\end_layout
\begin_layout Standard
Please have a short check that you are using a recent version of SDCC and
the bug is not yet known.
- This is the link for reporting bugs:
+ This is the link for reporting bugs:
\begin_inset LatexCommand \htmlurl{http://sourceforge.net/tracker/?group_id=599&atid=100599}
\end_inset
there must be some users.
So it's not exactly easy to find a new bug.
- If you find one we need it:
+ If you find one we need it:
\emph on
reporting bugs is good
\emph default
\begin_layout Standard
Like bug reports feature requests are forwarded to the developer mailing
list.
- This is the link for requesting features:
+ This is the link for requesting features:
\begin_inset LatexCommand \htmlurl{http://sourceforge.net/tracker/?group_id=599&atid=350599}
\end_inset
\end_inset
-:
+:
\begin_inset LatexCommand \url{http://sourceforge.net/tracker/?group_id=599&atid=300599}
\end_inset
\end_layout
\begin_layout Standard
-You need to specify some parameters to the
+You need to specify some parameters to the
\family typewriter
diff
\family default
command for the patches to be useful.
If you modified more than one file a patch created f.e.
- with
+ with
\family sans
\series bold
\family default
\series default
- will be fine, otherwise
+ will be fine, otherwise
\family sans
\series bold
\series default
-
+
\family default
will do.
\end_layout
\end_layout
\begin_layout Standard
-These links should take you directly to the
+These links should take you directly to the
\begin_inset LatexCommand \url[Mailing lists]{http://sourceforge.net/mail/?group_id=599}
\end_inset
\end_inset
- and the
+ and the
\begin_inset LatexCommand \url[Forums]{http://sourceforge.net/forum/?group_id=599}
\end_inset
in the Subversion repository
\size footnotesize
-
-\begin_inset LatexCommand \htmlurl{http://svn.sourceforge.net/viewcvs.cgi/*checkout*/sdcc/trunk/sdcc/ChangeLog}
+
+\begin_inset LatexCommand \htmlurl{http://sdcc.svn.sourceforge.net/viewcvs.cgi/*checkout*/sdcc/trunk/sdcc/ChangeLog}
\end_inset
\end_layout
\begin_layout Standard
-The output of
+The output of
\family sans
\series bold
-sdcc --version
+sdcc -
+\family default
+
+\begin_inset ERT
+status open
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+
+\family sans
+-version
\family default
\series default
or the filenames of the snapshot versions of SDCC include date and its
number.
Subversion allows to download the source of recent or previous versions
-
+
\begin_inset LatexCommand \url{http://sourceforge.net/svn/?group_id=599}
\end_inset
but as this was fixed a while ago, the current problem is that another
excuse has to be found.
Kidding aside, we have to get better there! On the other hand there are
- daily snapshots available at
+ daily snapshots available at
\begin_inset LatexCommand \htmlurl[snap]{http://sdcc.sourceforge.net/snap.php}
\end_inset
, and you can always build the very last version (hopefully with many bugs
- fixed, and features added) from the source code available at
+ fixed, and features added) from the source code available at
\begin_inset LatexCommand \htmlurl[Source]{http://sdcc.sourceforge.net/snap.php#Source}
\end_inset
.
- A release wiki
+ The SDCC Wiki
\begin_inset LatexCommand \index{wiki}
\end_inset
-\begin_inset LatexCommand \index{Release wiki}
+\begin_inset LatexCommand \index{SDCC Wiki}
\end_inset
- at
-\begin_inset LatexCommand \url{http://sdcc.sf.net/release_wiki/}
+ at
+\begin_inset LatexCommand \url{http://sdcc.wiki.sourceforge.net/}
\end_inset
\end_layout
\begin_layout Standard
-You'll find some small examples in the directory
+You'll find some small examples in the directory
\emph on
sdcc/device/examples/.
-
+
\emph default
More examples and libraries are available at
\emph on
- The SDCC Open Knowledge Resource
+ The SDCC Open Knowledge Resource
\begin_inset LatexCommand \url{http://sdccokr.dl9sec.de/}
\end_inset
-
+
\emph default
-web site or at
+web site or at
\begin_inset LatexCommand \url{http://www.pjrc.com/tech/8051/}
\end_inset
\end_layout
\begin_layout Standard
-\begin_inset Note Comment
+\begin_inset Note Note
status collapsed
\begin_layout Standard
\end_layout
\begin_layout Standard
-The compiler is passed through nightly compile and build checks.
- The so called
+The compiler is passed through snaphot build compile and build checks.
+ The so called
\shape italic
regression tests
\shape default
\end_inset
check that SDCC itself compiles flawlessly on several host platforms (i386,
- Opteron, 64 bit Alpha, ppc64, MacOS X on PPC, Solaris on Sparc) and checks
- the quality of the code generated by SDCC by running the code for several
- target platforms through simulators.
+ Opteron, 64 bit Alpha, ppc64, Mac OS X on ppc and i386, Solaris on Sparc)
+ and checks the quality of the code generated by SDCC by running the code
+ for several target platforms through simulators.
The regression test suite comprises more than 100 files which expand to
more than 500 test cases which include more than 4500 tests.
The results of these tests are published daily on SDCC's snapshot page
- (click on the red or green symbols on the right side of
+ (click on the red or green symbols on the right side of
\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/snap.php}
\end_inset
\end_layout
\begin_layout Standard
-There is a separate document
+There is a separate document
\shape italic
-test_suite.pdf
+test_suite.pdf
\begin_inset LatexCommand \index{Test suite}
\end_inset
\shape default
-
+
\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/doc/test_suite_spec.pdf}
\end_inset
\end_layout
\begin_layout Standard
-You'll find the test code in the directory
+You'll find the test code in the directory
\shape italic
sdcc/support/regression
\shape default
.
- You can run these tests manually by running
+ You can run these tests manually by running
\family sans
make
\family default
in this directory (or f.e.
-
+
\family sans
\series bold
\end_layout
\begin_layout Standard
-The 14bit pic port uses a different set of regression tests
+The PIC14 port uses a different set of regression tests
\begin_inset LatexCommand \index{Regression test (PIC14)}
\end_inset
-, you'll find them in the directory
+, you'll find them in the directory
\shape italic
sdcc/src/regression
\shape default
\end_layout
\begin_layout Standard
-In short:
+In short:
\emph on
highly
\emph default
\end_layout
\begin_layout Enumerate
-give students a chance to understand the
+give students a chance to understand the
\emph on
complete
\emph default
\end_inset
-,
+,
\begin_inset LatexCommand \url[Oregano]{http://www.oregano.at/ip/ip01.htm}
\end_inset
\begin_layout Enumerate
be able to insert excursions about skills like using a revision control
system, submitting/applying patches, using a type-setting (as opposed to
- word-processing) engine LyX/LaTeX, using
+ word-processing) engine LyX/LaTeX, using
\begin_inset LatexCommand \url[SourceForge]{http://www.sf.net}
\end_inset
-, following some
+, following some
\begin_inset LatexCommand \url[netiquette]{http://en.wikipedia.org/wiki/Netiquette}
\end_inset
\end_inset
.
-
+
\newline
And if there should be a shortage of ideas then you can always point students
- to the ever-growing feature request list
+ to the ever-growing feature request list
\begin_inset LatexCommand \htmlurl{http://sourceforge.net/tracker/?group_id=599&atid=350599}
\end_inset
\begin_layout Enumerate
not tie students to a specific host platform and instead allow them to use
- a host platform of
+ a host platform of
\emph on
their
\emph default
- choice (among them Alpha, i386, i386_64, MacOs, Mips, Sparc, Windows and
- eventually
+ choice (among them Alpha, i386, i386_64, Mac OS X, Mips, Sparc, Windows
+ and eventually
\begin_inset LatexCommand \url[OLPC]{http://www.laptop.org}
\end_inset
\begin_layout Standard
then SDCC is probably among the first choices.
Well, probably SDCC might be the only choice.
-\end_layout
-
-\begin_layout Standard
-
\newpage
\end_layout
\begin_layout Standard
SDCC performs a host of standard optimizations in addition to some MCU specific
optimizations.
-
+
\end_layout
\begin_layout Subsection
\end_layout
\begin_layout Standard
-The compiler does local and
+The compiler does local and
\emph on
g
\emph default
-lobal
+lobal
\emph on
c
\emph default
-ommon
+ommon
\emph on
s
\emph default
-ubexpression
+ubexpression
\emph on
e
\emph default
-limination, e.g.:
+limination, e.g.:
\end_layout
\begin_layout Verse
\family typewriter
-i = x + y + 1;
+i = x + y + 1;
\newline
j = x + y;
\end_layout
\begin_layout Verse
\family typewriter
-iTemp = x + y;
+iTemp = x + y;
\newline
-i = iTemp + 1;
+i = iTemp + 1;
\newline
j = iTemp;
\end_layout
\begin_layout Verse
\family typewriter
-a->b[i].c = 10;
+a->b[i].c = 10;
\newline
a->b[i].d = 11;
\end_layout
\begin_layout Verse
\family typewriter
-iTemp = a->b[i];
+iTemp = a->b[i];
\newline
-iTemp.c = 10;
+iTemp.c = 10;
\newline
iTemp.d = 11;
\end_layout
\newline
\newline
-void f () {
+void f () {
\newline
\InsetSpace ~
\InsetSpace ~
-int i;
+int i;
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-/* dead store */
+/* dead store */
\newline
\InsetSpace ~
\InsetSpace ~
global = 1;\InsetSpace ~
/* dead
- store */
+ store */
\newline
\InsetSpace ~
\InsetSpace ~
-global = 2;
+global = 2;
\newline
\InsetSpace ~
\InsetSpace ~
-return;
+return;
\newline
\InsetSpace ~
\InsetSpace ~
global = 3;\InsetSpace ~
-/* unreachable */
+/* unreachable */
\newline
}
\end_layout
\newline
\InsetSpace ~
\InsetSpace ~
-global = 2;
+global = 2;
\newline
}
\end_layout
\begin_layout Verse
\family typewriter
-int f() {
+int f() {
\newline
\InsetSpace ~
\InsetSpace ~
-int i, j;
+int i, j;
\newline
\InsetSpace ~
\InsetSpace ~
-i = 10;
+i = 10;
\newline
\InsetSpace ~
\InsetSpace ~
-j = i;
+j = i;
\newline
\InsetSpace ~
\InsetSpace ~
-return j;
+return j;
\newline
}
\end_layout
\begin_layout Standard
-will be changed to
+will be changed to
\end_layout
\begin_layout Verse
\family typewriter
-int f() {
+int f() {
\newline
\InsetSpace ~
\InsetSpace ~
-int i, j;
+int i, j;
\newline
\InsetSpace ~
\InsetSpace ~
-i = 10;
+i = 10;
\newline
\InsetSpace ~
\InsetSpace ~
-j = 10;
+j = 10;
\newline
\InsetSpace ~
\InsetSpace ~
-return 10;
+return 10;
\newline
}
\end_layout
\end_layout
\begin_layout Standard
-Two types of loop optimizations are done by SDCC
+Two types of loop optimizations are done by SDCC
\emph on
loop invariant
\emph default
\begin_layout Verse
\family typewriter
-for (i = 0 ; i < 100 ; i ++)
+for (i = 0 ; i < 100 ; i ++)
\newline
\InsetSpace ~
\InsetSpace ~
\begin_layout Verse
\family typewriter
-itemp = k + l;
+itemp = k + l;
\newline
-for (i = 0; i < 100; i++)
+for (i = 0; i < 100; i++)
\newline
\InsetSpace ~
\InsetSpace ~
\begin_layout Verse
\family typewriter
-itemp1 = 0;
+itemp1 = 0;
\newline
-itemp2 = 0;
+itemp2 = 0;
\newline
-for (i=0;i< 100;i++) {
+for (i=0;i< 100;i++) {
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-ar[itemp1] = itemp2;
+ar[itemp1] = itemp2;
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
itemp1
- += 5;
+ += 5;
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-itemp2 += 3;
+itemp2 += 3;
\newline
}
\end_layout
\begin_layout Standard
This optimization is done to reduce the overhead of checking loop boundaries
for every iteration.
- Some simple loops can be reversed and implemented using a
+ Some simple loops can be reversed and implemented using a
\begin_inset Quotes eld
\end_inset
\end_layout
\begin_layout Itemize
-The 'for' loop is of the form
+The 'for' loop is of the form
\newline
\newline
\end_layout
\begin_layout Itemize
-The <for body> does not contain
+The <for body> does not contain
\begin_inset Quotes eld
\end_inset
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
- i = j;
+ i = j;
\newline
i /= 2;\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
- i >>= 1;
+ i >>= 1;
\newline
i
= j - j;\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
- i = 0;
+ i = 0;
\newline
i = j / 1;\InsetSpace ~
\InsetSpace ~
.
It makes the decision based on an estimate of the generated code size.
- SDCC is quite liberal in the requirements for jump table generation:
+ SDCC is quite liberal in the requirements for jump table generation:
\end_layout
\begin_layout Itemize
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-switch (i) {
+switch (i) {
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
case 0: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
case 1: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
case 3: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
case 4: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
case 5: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
case 6: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
case 7: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
case 8: ...
-
+
\newline
}\InsetSpace ~
\InsetSpace ~
If the case labels are not in numerical sequence ('gaps' between cases)
SDCC checks whether a jump table with additionally inserted dummy cases
is still attractive.
-
+
\end_layout
\begin_layout Itemize
\begin_layout Verse
\family typewriter
-switch (i) {
+switch (i) {
\newline
\InsetSpace ~
\InsetSpace ~
case 1: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 2: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 3: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 4: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 5: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 6: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 7: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 101: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 102: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 103: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 104: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 105: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 106: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 107: ...
-
+
\newline
}
\end_layout
\begin_layout Verse
\family typewriter
-switch (i) {
+switch (i) {
\newline
\InsetSpace ~
\InsetSpace ~
case 1: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 2: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 3: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 4: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 5: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 6: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 7: ...
-
+
\newline
}
\end_layout
\begin_layout Verse
\family typewriter
-switch (i) {
+switch (i) {
\newline
\InsetSpace ~
\InsetSpace ~
case 101: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 102: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 103: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 104: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 105: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 106: ...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
case 107: ...
-
+
\newline
}
\end_layout
\end_layout
\begin_layout Standard
-\begin_inset Note Comment
+\begin_inset Note Note
status collapsed
\begin_layout Standard
\end_inset
- can be used to turn off checking the
+ can be used to turn off checking the
\emph on
j
\emph default
-ump
+ump
\emph on
t
\emph default
-able
+able
\emph on
bound
\emph default
unsigned char i;
\newline
...
-
+
\newline
-i >>= 4;
+i >>= 4;
\newline
...
\end_layout
\family typewriter
mov\InsetSpace ~
- a,_i
+ a,_i
\newline
-swap a
+swap a
\newline
anl\InsetSpace ~
- a,#0x0f
+ a,#0x0f
\newline
mov\InsetSpace ~
_i,a
\begin_layout Verse
\family typewriter
-unsigned int i;
+unsigned int i;
\newline
...
-
+
\newline
-i >>= 9;
+i >>= 9;
\newline
...
\end_layout
\family typewriter
mov\InsetSpace ~
\InsetSpace ~
-a,(_i + 1)
+a,(_i + 1)
\newline
mov\InsetSpace ~
\InsetSpace ~
-(_i + 1),#0x00
+(_i + 1),#0x00
\newline
clr\InsetSpace ~
\InsetSpace ~
-c
+c
\newline
rrc\InsetSpace ~
\InsetSpace ~
-a
+a
\newline
mov\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-/* unsigned is needed for rotation */
+/* unsigned is needed for rotation */
\newline
...
-
+
\newline
-i = ((i << 1) | (i >> 7));
+i = ((i << 1) | (i >> 7));
\family default
\newline
\family typewriter
mov\InsetSpace ~
\InsetSpace ~
-a,_i
+a,_i
\newline
rl\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-a
+a
\newline
mov\InsetSpace ~
\InsetSpace ~
\begin_layout Standard
SDCC uses pattern matching on the parse tree to determine this operation.Variatio
-ns of this case will also be recognized as bit-rotation, i.e.:
+ns of this case will also be recognized as bit-rotation, i.e.:
\end_layout
\begin_layout Verse
\series default
\InsetSpace ~
\InsetSpace ~
-char i;
+char i;
\newline
\series bold
\series default
\InsetSpace ~
\InsetSpace ~
-int j;
+int j;
\newline
...
-
+
\newline
-i = ((i << 4) | (i >> 4));
+i = ((i << 4) | (i >> 4));
\family default
\newline
\family typewriter
-j = ((j << 8) | (j >> 8));
+j = ((j << 8) | (j >> 8));
\end_layout
\begin_layout Standard
\end_inset
.
- The
+ The
\begin_inset Quotes sld
\end_inset
\end_inset
example can be used to convert from little to big-endian or vice versa.
- If you want to change the endianness of a
+ If you want to change the endianness of a
\emph on
signed
\emph default
- integer you have to cast to
+ integer you have to cast to
\family typewriter
(unsigned int)
\family default
\begin_layout Standard
Usually 8-bit processors don't care much about endianness.
This is not the case for the standard 8051 which only has an instruction
- to increment its
+ to increment its
\emph on
dptr
\emph default
-datapointer
\emph on
-
+
\emph default
so little-endian is the more efficient byte order.
\end_layout
\begin_layout Verse
\family typewriter
-unsigned int gint;
+unsigned int gint;
\newline
\newline
-foo () {
+foo () {
\newline
\InsetSpace ~
\InsetSpace ~
-unsigned char hob1, aob1;
+unsigned char hob1, aob1;
\newline
\InsetSpace ~
\InsetSpace ~
bit hob2, hob3, aob2,
- aob3;
+ aob3;
\newline
\InsetSpace ~
\InsetSpace ~
...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
-hob1 = (gint >> 15) & 1;
+hob1 = (gint >> 15) & 1;
\newline
\InsetSpace ~
\InsetSpace ~
-hob2 = (gint >> 15) & 1;
+hob2 = (gint >> 15) & 1;
\newline
\InsetSpace ~
\InsetSpace ~
hob3 = gint & 0x8000;
-
+
\newline
\InsetSpace ~
\InsetSpace ~
-aob1 = (gint >> 9) & 1;
+aob1 = (gint >> 9) & 1;
\newline
\InsetSpace ~
\InsetSpace ~
-aob2 = (gint >> 8) & 1;
+aob2 = (gint >> 8) & 1;
\newline
\InsetSpace ~
\InsetSpace ~
-aob3 = gint & 0x0800;
+aob3 = gint & 0x0800;
\newline
\InsetSpace ~
\InsetSpace ~
..
-
+
\newline
}
\end_layout
\InsetSpace ~
\InsetSpace ~
61 ;\InsetSpace ~
- hob.c 7
+ hob.c 7
\newline
000A E5*01\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
- a,(_gint + 1)
+ a,(_gint + 1)
\newline
000C 23\InsetSpace ~
\InsetSpace ~
rl\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
- a
+ a
\newline
000D 54 01\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
anl\InsetSpace ~
\InsetSpace ~
- a,#0x01
+ a,#0x01
\newline
000F F5*02\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
- _foo_hob1_1_1,a
+ _foo_hob1_1_1,a
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
66 ;\InsetSpace ~
- hob.c 8
+ hob.c 8
\newline
0011 E5*01\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
- a,(_gint + 1)
+ a,(_gint + 1)
\newline
0013 33\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
rlc\InsetSpace ~
\InsetSpace ~
- a
+ a
\newline
0014 92*00\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
_foo_hob2_1_1,c
-
+
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
66 ;\InsetSpace ~
- hob.c 9
+ hob.c 9
\newline
0016 E5*01\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
- a,(_gint + 1)
+ a,(_gint + 1)
\newline
0018 33\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
rlc\InsetSpace ~
\InsetSpace ~
- a
+ a
\newline
0019 92*01\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
- _foo_hob3_1_1,c
+ _foo_hob3_1_1,c
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
70 ;\InsetSpace ~
- hob.c 10
+ hob.c 10
\newline
001B E5*01\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
- a,(_gint + 1)
+ a,(_gint + 1)
\newline
001D
03\InsetSpace ~
rr\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
- a
+ a
\newline
001E 54 01\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
anl\InsetSpace ~
\InsetSpace ~
- a,#0x01
+ a,#0x01
\newline
0020 F5*03\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
_foo_aob1_1_1,a
-
+
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
75 ;\InsetSpace ~
- hob.c 11
+ hob.c 11
\newline
0022 E5*01\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
- a,(_gint + 1)
+ a,(_gint + 1)
\newline
0024 13\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
rrc\InsetSpace ~
\InsetSpace ~
- a
+ a
\newline
0025 92*02\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
- _foo_aob2_1_1,c
+ _foo_aob2_1_1,c
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
79 ;\InsetSpace ~
- hob.c 12
+ hob.c 12
\newline
0027 E5*01\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
- a,(_gint + 1)
+ a,(_gint + 1)
\newline
0029
A2 E3\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
- c,acc[3]
+ c,acc[3]
\newline
002B 92*03\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
- _foo_aob3_1_1,c
+ _foo_aob3_1_1,c
\end_layout
\begin_layout Standard
-Other variations of these cases however will
+Other variations of these cases however will
\emph on
not
\emph default
\begin_layout Verse
\family typewriter
-unsigned int gint;
+unsigned int gint;
\newline
-unsigned long int glong;
+unsigned long int glong;
\newline
\newline
-foo () {
+foo () {
\newline
\InsetSpace ~
\InsetSpace ~
unsigned char hob1,
- hob2;
+ hob2;
\newline
\InsetSpace ~
\InsetSpace ~
-unsigned int how1, how2;
+unsigned int how1, how2;
\newline
\InsetSpace ~
\InsetSpace ~
...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
-hob1 = (gint >> 8) & 0xFF;
+hob1 = (gint >> 8) & 0xFF;
\newline
\InsetSpace ~
\InsetSpace ~
-hob2 = glong >> 24;
+hob2 = glong >> 24;
\newline
\InsetSpace ~
\InsetSpace ~
how1 = (glong >> 16) & 0xFFFF;
-
+
\newline
\InsetSpace ~
\InsetSpace ~
-how2 = glong >> 8;
+how2 = glong >> 8;
\newline
\InsetSpace ~
\InsetSpace ~
..
-
+
\newline
}
\end_layout
\InsetSpace ~
\InsetSpace ~
91 ;\InsetSpace ~
- hob.c 15
+ hob.c 15
\newline
0037 85*01*06\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
- _foo_hob1_1_1,(_gint + 1)
+ _foo_hob1_1_1,(_gint + 1)
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
93 ;\InsetSpace ~
hob.c
- 16
+ 16
\newline
003A 85*05*07\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
- _foo_hob2_1_1,(_glong + 3)
+ _foo_hob2_1_1,(_glong + 3)
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
95 ;\InsetSpace ~
- hob.c 17
+ hob.c 17
\newline
003D 85*04*08\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
- _foo_how1_1_1,(_glong + 2)
+ _foo_how1_1_1,(_glong + 2)
\newline
0040 85*05*09\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
(_foo_how1_1_1 +
- 1),(_glong + 3)
+ 1),(_glong + 3)
\newline
0043 85*03*0A\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
- _foo_how2_1_1,(_glong + 1)
+ _foo_how2_1_1,(_glong + 1)
\newline
0046 85*04*0B\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
mov\InsetSpace ~
\InsetSpace ~
- (_foo_how2_1_1 + 1),(_glong + 2)
+ (_foo_how2_1_1 + 1),(_glong + 2)
\end_layout
\begin_layout Standard
-Again, variations of these cases may
+Again, variations of these cases may
\emph on
not
\emph default
\begin_layout Standard
The compiler uses a rule based, pattern matching and re-writing mechanism
for peep-hole optimization.
- It is inspired by
+ It is inspired by
\emph on
copt
\emph default
@\InsetSpace ~
microsoft.com).
A default set of rules are compiled into the compiler, additional rules
- may be added with the
+ may be added with the
\emph on
-
\begin_inset ERT
\begin_layout Verse
\family typewriter
-replace {
+replace {
\newline
\InsetSpace ~
\InsetSpace ~
-mov %1,a
+mov %1,a
\newline
\InsetSpace ~
\InsetSpace ~
\begin_layout Verse
\family typewriter
-mov r1,a
+mov r1,a
\newline
mov a,r1
\end_layout
\end_layout
\begin_layout Standard
-Note: All occurrences of a
+Note: All occurrences of a
\emph on
%n
\emph default
\begin_layout Verse
\family typewriter
-mov r1,a
+mov r1,a
\newline
mov a,r2
\end_layout
\newline
Other special case optimizations may be added by the
- user (via
+ user (via
\emph on
-
\begin_inset ERT
\end_inset
- allow only
+ allow only
\family typewriter
ajmp
\family default
- and
+ and
\family typewriter
acall
\family default
.
- The following two rules will change all
+ The following two rules will change all
\family typewriter
ljmp
\family default
- and
+ and
\family typewriter
lcall
\family default
- to
+ to
\family typewriter
ajmp
\family default
- and
+ and
\family typewriter
acall
\end_layout
\begin_layout Verse
\family typewriter
-replace { lcall %1 } by { acall %1 }
+replace { lcall %1 } by { acall %1 }
\newline
replace { ljmp %1 } by { ajmp %1 }
\end_layout
\begin_layout Standard
-The
+(NOTE: from version 2.7.3 on, you can use option -
+\emph on
+
+\begin_inset ERT
+status collapsed
+
+\begin_layout Standard
+
+
+\backslash
+/
+\end_layout
+
+\end_inset
+
+
+\emph default
+-acall-ajmp
+\begin_inset LatexCommand \index{-\/-acall-ajmp}
+
+\end_inset
+
+, which also takes care of aligning the interrupt vectors properly.)
+\newline
+
+\end_layout
+
+\begin_layout Standard
+The
\emph on
inline-assembler code
\emph default
\family typewriter
rule := replace [ restart ] '{' <assembly sequence> '
\backslash
-n'
+n'
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
'}' by '{' '
\backslash
-n'
+n'
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
<assembly sequence> '
\backslash
-n'
+n'
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
'}' [if <functionName> ] '
\backslash
-n'
+n'
\end_layout
\begin_layout Standard
\begin_layout Verse
\family typewriter
-replace restart {
+replace restart {
\newline
\InsetSpace ~
\InsetSpace ~
-pop %1
+pop %1
\newline
\InsetSpace ~
\InsetSpace ~
-push %1 } by {
+push %1 } by {
\newline
\InsetSpace ~
\InsetSpace ~
-; nop
+; nop
\newline
}
\end_layout
\begin_layout Verse
\family typewriter
-pop ar1
+pop ar1
\newline
-pop ar2
+pop ar2
\newline
-push ar2
+push ar2
\newline
push ar1
\end_layout
\begin_layout Verse
\family typewriter
-pop ar1
+pop ar1
\newline
-; nop
+; nop
\newline
push ar1
\end_layout
\begin_layout Verse
\family typewriter
-; nop
+; nop
\newline
; nop
\end_layout
\begin_layout Verse
\family typewriter
-replace {
+replace {
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-ljmp %5
+ljmp %5
\newline
%2:
\newline
-} by {
+} by {
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-sjmp %5
+sjmp %5
\newline
%2:
\newline
\begin_layout Standard
The optimizer does a look-up of a function name table defined in function
-
+
\emph on
callFuncByName
\emph default
- in the source file SDCCpeeph.c, with the name
+ in the source file SDCCpeeph.c, with the name
\emph on
labelInRange
\emph default
.
If it finds a corresponding entry the function is called.
Note there can be no parameters specified for these functions, in this
- case the use of
+ case the use of
\emph on
%5
\emph default
- is crucial, since the function
+ is crucial, since the function
\emph on
labelInRange
\emph default
g the variable bindings is passed as a parameter).
If you want to code more such functions, take a close look at the function
labelInRange and the calling mechanism in source file SDCCpeeph.c.
- Currently implemented are
+ Currently implemented are
\emph on
labelInRange, labelRefCount, labelIsReturnOnly, operandsNotSame, xramMovcOption,
- 24bitMode, portIsDS390, 24bitModeAndPortDS390
+ 24bitMode, portIsDS390, 24bitModeAndPortDS390
\emph default
and
\emph on
\end_layout
\begin_layout Standard
-The latest publically available version of the standard
+The latest publically available version of the standard
\emph on
ISO/IEC 9899 - Programming languages - C
\emph default
- should be available at:
+ should be available at:
\begin_inset LatexCommand \url{http://www.open-std.org/jtc1/sc22/wg14/www/standards.html#9899}
\end_inset
\end_inset
- unless explicitly declared as such or the
+ unless explicitly declared as such or the
\series bold
-
\begin_inset ERT
\family typewriter
struct s { ...
- };
+ };
\newline
-struct s s1, s2;
+struct s s1, s2;
\newline
-foo()
+foo()
\newline
-{
+{
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-s1 = s2 ; /* is invalid in SDCC although allowed in ANSI */
+s1 = s2 ; /* is invalid in SDCC although allowed in ANSI */
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
...
-
+
\newline
}
\newline
\series default
s parms) /* invalid in SDCC although allowed in ANSI */
\newline
-{
+{
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
struct s rets;
-
+
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
...
-
+
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-return rets; /* is invalid in SDCC although allowed in ANSI */
+return rets; /* is invalid in SDCC although allowed in ANSI */
\newline
}
\end_layout
\end_inset
-' precision floating point
+' precision floating point
\begin_inset LatexCommand \index{Floating point support}
\end_inset
\begin_layout Verse
\family typewriter
-foo(i,j) /* this old style of function declarations */
+foo(i,j) /* this old style of function declarations */
\newline
-int i,j; /* are valid
- in ANSI but not valid in SDCC */
+int i,j; /* is valid
+ in ANSI but not valid in SDCC */
\newline
-{
+{
\newline
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
...
-
+
\newline
}
\end_layout
\end_deeper
\begin_layout Itemize
-Most enhancements in C99 are not supported, f.e.:
+Most enhancements in C99 are not supported, e.g.:
+\end_layout
+
+\begin_deeper
+\begin_layout Verse
+
+\family typewriter
+for (
+\series bold
+int
+\series default
+ i=0; i<10; i++) /* is invalid in SDCC although allowed in C99 */
+\end_layout
+
+\end_deeper
+\begin_layout Itemize
+But some have been added recently in SDCC 2.7.0.
+ They must be considered alpha quality however.
\end_layout
\begin_deeper
\series default
- int increment (int a) { return a+1; } /* is invalid in SDCC although allowed
- in C99.
- An empty define
-\emph on
-#define inline
-\emph default
- can be used as a work around */
+ int increment (int a) { return a+1; } /* inlines the increment without
+ function call overhead */
\newline
-
-\newline
-for (
+int *
\series bold
-int
+restrict
+\begin_inset LatexCommand \index{inline (not supported)}
+
+\end_inset
+
+
\series default
- i=0; i<10; i++) /* is invalid in SDCC although allowed in C99 */
+ p; /* accepted but ignored */
\end_layout
\end_deeper
\begin_layout Itemize
Certain words that are valid identifiers in the standard may be reserved
- words in SDCC unless the
+ words in SDCC unless the
\series bold
-
\begin_inset ERT
code in a function.
Large functions can have low complexity, and small functions can have large
complexity levels.
-
+
\newline
\newline
\end_layout
\begin_layout Standard
-More information is available in a wiki
+More information is available on SDCC Wiki
\begin_inset LatexCommand \index{wiki}
\end_inset
- (preliminary link
-\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/release_wiki/index.php?page=SDCC+internals+and+porting}
+ (preliminary link
+\begin_inset LatexCommand \url{http://sdcc.wiki.sourceforge.net/SDCC+internals+and+porting}
\end_inset
-) and in the thread
+) and in the thread
\begin_inset LatexCommand \url{http://sf.net/mailarchive/message.php?msg_id=13954144}
\end_inset
\shape italic
This is an excerpt from an article published in Circuit Cellar Magazine
- in
+ in
\series bold
August 2000
\series default
The current version of SDCC can generate code for Intel 8051 and Z80 MCU.
It is fairly easy to retarget for other 8-bit MCU.
Here we take a look at some of the internals of the compiler.
-
+
\end_layout
\begin_layout Paragraph*
\end_inset
-
+
\end_layout
\begin_layout Standard
basic block being processed, if there are any found then it will push that
operand and use the registers in this block, the operand will then be popped
at the end of the basic block.
-
+
\end_layout
\begin_layout Standard
example, the z80 port does not use registers to pass parameters so the
SEND and RECV iCode operations will not be generated, and it also does
not support JUMPTABLES.
-
+
\newline
\end_layout
\begin_layout Standard
\size footnotesize
-Figure II
+Figure II
\begin_inset Tabular
<lyxtabular version="3" rows="39" columns="4">
<features islongtable="true" headBottomDL="true">
\begin_layout Standard
\size footnotesize
-NOT operation
+NOT operation
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-Bitwise complement of
+Bitwise complement of
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-Pop the operand from the stack
+Pop the operand from the stack
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-Call the function represented by IC_LEFT
+Call the function represented by IC_LEFT
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-Return the value in operand IC_LEFT
+Return the value in operand IC_LEFT
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-IC_LABEL()
+IC_LABEL()
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-IC_LABEL()
+IC_LABEL()
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-IC_RESULT = IC_LEFT - IC_RIGHT
+IC_RESULT = IC_LEFT - IC_RIGHT
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-Multiplication
+Multiplication
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-Greater than
+Greater than
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-Equal to
+Equal to
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-IC_LEFT() IC_RIGHT() IC_RESULT()
+IC_LEFT() IC_RIGHT() IC_RESULT()
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-IC_RESULT = IC_LEFT && IC_RIGHT;
+IC_RESULT = IC_LEFT && IC_RIGHT;
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-IC_LEFT() IC_RIGHT() IC_RESULT()
+IC_LEFT() IC_RIGHT() IC_RESULT()
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-Logical or operation
+Logical or operation
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-IC_RESULT = IC_LEFT || IC_RIGHT;
+IC_RESULT = IC_LEFT || IC_RIGHT;
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-IC_LEFT() IC_RIGHT() IC_RESULT()
+IC_LEFT() IC_RIGHT() IC_RESULT()
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-IC_LEFT() IC_RIGHT() IC_RESULT()
+IC_LEFT() IC_RIGHT() IC_RESULT()
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-Bitwise OR
+Bitwise OR
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-Bitwise AND
+Bitwise AND
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-Left shift
+Left shift
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-IC_RESULT = IC_LEFT << IC_RIGHT
+IC_RESULT = IC_LEFT << IC_RIGHT
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-IC_RESULT = IC_LEFT >> IC_RIGHT
+IC_RESULT = IC_LEFT >> IC_RIGHT
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-Indirect fetch
+Indirect fetch
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-IC_RIGHT() IC_RESULT()
+IC_RIGHT() IC_RESULT()
\end_layout
\end_inset
\size footnotesize
Conditional jump.
If true label is present then jump to true label if condition is true else
- jump to false label if condition is false
+ jump to false label if condition is false
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-if (IC_COND) goto IC_TRUE;
+if (IC_COND) goto IC_TRUE;
\newline
\InsetSpace ~
\InsetSpace ~
-Or
+Or
\newline
If (!IC_COND) goto IC_FALSE;
\end_layout
\begin_layout Standard
\size footnotesize
-Address of
+Address of
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-Cast types
+Cast types
\end_layout
\end_inset
\begin_layout Standard
\size footnotesize
-This is used for passing parameters in registers;
+This is used for passing parameters in registers;
\newline
move IC_LEFT to the next
available parameter register.
This is used for receiving parameters passed in registers;
\newline
Move the values
- in the next parameter register to IC_RESULT
+ in the next parameter register to IC_RESULT
\end_layout
\end_inset
\shape slanted
\size footnotesize
see f.e.
-
+
\family typewriter
gen51Code()
\family default
- in
+ in
\family typewriter
src/mcs51/gen.c
\end_layout
\end_layout
\begin_layout Standard
-\begin_inset Note Comment
+\begin_inset Note Note
status collapsed
\begin_layout Standard
-In the original article Figure II was announced to be downloadable on
+In the original article Figure II was announced to be downloadable on
\shape italic
Circuit Cellar
\shape default
11.\InsetSpace ~
\InsetSpace ~
while (*x) *x++
- = *p++;
+ = *p++;
\newline
12.\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
\InsetSpace ~
-sum = 0 ;
+sum = 0 ;
\newline
13.\InsetSpace ~
\InsetSpace ~
\newline
As mentioned earlier the live ranges are computed in terms of the execution
- sequence number of the iCodes, for example
+ sequence number of the iCodes, for example
\newline
the iTemp0 is live from (i.e.
first defined in iCode with execution sequence number 3, and is last used
\begin_layout Standard
\size footnotesize
-Sample.c(11:3:2:0) iTemp0 [lr3:5]{_near * int}[r2] = recv
+Sample.c(11:3:2:0) iTemp0 [lr3:5]{_near * int}[r2] = recv
\end_layout
\begin_layout Standard
\begin_layout Standard
\size footnotesize
-; iTemp0 [lr3:5]{_near * int}[r2] = recv
+; iTemp0 [lr3:5]{_near * int}[r2] = recv
\end_layout
\begin_layout Standard
\begin_layout Standard
\size footnotesize
-; iTemp6 [lr5:16]{_near * int}[r0] =
+; iTemp6 [lr5:16]{_near * int}[r0] =
\end_layout
\begin_layout Standard
\size footnotesize
-; iTemp6 [lr5:16]{_near * int}[r0] +
+; iTemp6 [lr5:16]{_near * int}[r0] +
\end_layout
\begin_layout Standard
\begin_layout Standard
\size footnotesize
-; iTemp2 [lr18:40]{short}[r2] = iTemp2 [lr18:40]{short}[r2] +
+; iTemp2 [lr18:40]{short}[r2] = iTemp2 [lr18:40]{short}[r2] +
\end_layout
\begin_layout Standard
\begin_layout Standard
\size footnotesize
-; iTemp11 [lr19:40]{short}[r3] = iTemp11 [lr19:40]{short}[r3] +
+; iTemp11 [lr19:40]{short}[r3] = iTemp11 [lr19:40]{short}[r3] +
\end_layout
\begin_layout Standard
\newline
\emph on
-Also thanks to Sourceforge
+Thanks to Sourceforge
\begin_inset LatexCommand \url{http://www.sf.net}
\end_inset
which has hosted the project since 1999 and donates significant download
- bandwidth and probably more than
-\begin_inset ERT
-status collapsed
-
-\begin_layout Standard
-
-$10^{13}$
-\end_layout
-
-\end_inset
+ bandwidth.
+\emph default
-CPU cycles per day.
\newline
-
-\begin_inset Note Note
-status open
-\begin_layout Standard
-more than 10^13 is an estimate: on my Athlon 2800+ it takes about (0.5+6.5+20)
- minutes for (configure+make+regression test), and there is (i386, amd64,
- alpha, ppc64, (mingw32), sparc, macosx).
-
-\end_layout
-
-\end_inset
+\newline
+\emph on
+Also thanks to all SDCC Distributed Compile Farm members for donating CPU
+ cycles and bandwidth for snapshot builds.
+\newline
\end_layout
\end_inset
of their respective companies.
-
+
\end_layout
\begin_layout Section*
projects / fw / sdcc / blobdiff