\lyxformat 221
\textclass book
\begin_preamble
+\pdfoptionpdfminorversion=3
\usepackage[
pdftitle={SDCC Compiler User Guide},
pdfauthor={SDCC development team},
pdfsubject={installation, user manual},
- pdfkeywords={8032, 8051, ansi, c, compiler, CPU, DS390,
- embedded, GPL, HC08, manual, mcs51, PIC, Z80},
+ pdfkeywords={8032 8051 ansi c compiler CPU DS390
+ embedded GPL HC08 manual mcs51 microcontroller PIC Z80},
colorlinks=true,
linkcolor=blue] {hyperref}
%
\size normal
-SDCC 2.4.0
+SDCC 2.5.5
\size footnotesize
\newline
$Revision$
\layout Comment
-The above strings enclosed in $ are automatically updated by cvs
+The above strings enclosed in $ are automatically updated by Subversion
\layout Standard
\emph on
C
\emph default
-ompiler) is a Freeware, retargettable, optimizing ANSI-C compiler by
+ompiler) is an open source, retargettable, optimizing ANSI-C compiler by
+
\series bold
Sandeep Dutta
\series default
\end_inset
-, etc.), Dallas DS80C390 variants, Motorola HC08 and Zilog Z80 based MCUs.
+, etc.), Dallas DS80C390 variants, Freescale (formerly Motorola) HC08 and
+ Zilog Z80 based MCUs.
It can be retargetted for other microprocessors, support for Microchip
PIC, Atmel AVR is under development.
The entire source code for the compiler is distributed under GPL.
- SDCC uses ASXXXX & ASLINK, a Freeware, retargettable assembler & linker.
+ SDCC uses ASXXXX
+\begin_inset LatexCommand \index{asXXXX (as-gbz80, as-hc08, asx8051, as-z80)}
+
+\end_inset
+
+ & ASLINK
+\begin_inset LatexCommand \index{aslink}
+
+\end_inset
+
+, an open source retargettable assembler & linker.
SDCC has extensive language extensions suitable for utilizing various microcont
rollers and underlying hardware effectively.
\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.
+ SDCDB and ucSim are currently not available on Win32 platforms.
\newline
All packages used in this compiler system are
\emph on
-opensource
+open source
\emph default
and
\emph on
\layout Section
Compatibility with previous versions
+\begin_inset LatexCommand \index{Compatibility with previous versions}
+
+\end_inset
+
+
\layout Standard
This version has numerous bug fixes compared with the previous version.
\layout Itemize
short is now equivalent to int (16 bits), it used to be equivalent to char
- (8 bits) which is not ANSI compliant
+ (8 bits) which is not ANSI compliant.
\layout Itemize
the default directory for gcc-builds where include, library and documentation
- files are stored is now in /usr/local/share
+ files are stored is now in /usr/local/share.
\layout Itemize
char type parameters to vararg functions are casted to int unless explicitly
/
\end_inset
--regextend has been removed
+-regextend has been removed.
\layout Itemize
option -
/
\end_inset
--noregparms has been removed
+-noregparms has been removed.
\layout Itemize
option -
/
\end_inset
--stack-after-data has been removed
+-stack-after-data has been removed.
+\layout Itemize
+
+bit
+\begin_inset LatexCommand \index{bit}
+
+\end_inset
+
+ and sbit
+\begin_inset LatexCommand \index{sbit}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_sbit}
+
+\end_inset
+
+ types now consistently behave like the C99 _Bool type with respect to type
+ conversion
+\begin_inset LatexCommand \index{type conversion}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{type promotion}
+
+\end_inset
+
+.
+ The most common incompatibility resulting from this change is related to
+ bit toggling
+\begin_inset LatexCommand \index{Bit toggling}
+
+\end_inset
+
+ idioms, e.g.:
+\newline
+
+\family typewriter
+\SpecialChar ~
+\SpecialChar ~
+bit b;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+b = ~b; /* equivalent to b=1 instead of toggling b */
+\newline
+\SpecialChar ~
+\SpecialChar ~
+b = !b; /* toggles b */
+\newline
+
+\family default
+In previous versions, both forms would have toggled the bit.
\layout Standard
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
+\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 by anonymous CVS on cvs.sdcc.sourceforge.net.
+ is available directly from Subversion on https://svn.sourceforge.net/svnroot/sdcc
+/trunk/sdcc.
\layout Section
Wishes for the future
\family typewriter
-code banking
-\begin_inset LatexCommand \index{code banking (not supported)}
+better code banking
+\begin_inset LatexCommand \index{code banking (limited support)}
\end_inset
\begin_inset Tabular
<lyxtabular version="3" rows="5" columns="4">
<features>
-<column alignment="center" valignment="top" leftline="true" width="0(null)">
-<column alignment="center" valignment="top" leftline="true" width="0(null)">
-<column alignment="center" valignment="top" leftline="true" width="0(null)">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0(null)">
+<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" bottomline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
Of course this doesn't change the search paths compiled into the binaries.
+\newline
+
+\newline
+Moreover the install path can be changed by defining DESTDIR
+\begin_inset LatexCommand \index{DESTDIR}
+
+\end_inset
+
+:
+\layout LyX-Code
+
+make install DESTDIR=$(HOME)/sdcc.rpm/
+\layout Standard
+
+Please note that DESTDIR must have a trailing slash!
\layout Section
Search Paths
\series medium
Download the source package
\series default
- either from the SDCC CVS repository or from the nightly snapshots
+ either from the SDCC Subversion repository or from the nightly snapshots
\series medium
, it will be named something like sdcc
\series default
later
\layout Itemize
-cvs ; only if you use CVS access
+svn ; only if you use Subversion access
\layout Standard
If you want to develop something you'll need:
And use an editor which can handle LF-only line endings.
Make sure not to commit files with windows line endings.
The tabulator spacing
-\begin_inset LatexCommand \index{tabulator spacing (8)}
+\begin_inset LatexCommand \index{tabulator spacing (8 columns)}
\end_inset
used in the project is 8.
+ Although a tabulator spacing of 8 is a sensible choice for programmers
+ (it's a power of 2 and allows to display 8/16 bit signed variables without
+ loosing columns) the plan is to move towards using only spaces in the source.
\layout Subsection
Building SDCC Using Microsoft Visual C++ 6.0/NET (MSVC)
\series medium
Download the source package
\series default
- either from the SDCC CVS repository or from the
+ either from the SDCC Subversion repository or from the
\begin_inset LatexCommand \url[nightly snapshots]{http://sdcc.sourceforge.net/snap.php}
\end_inset
\newline
+\newline
+WARNING: Visual studio is very picky with line terminations; it expects
+ the 0x0d, 0x0a DOS style line endings, not the 0x0a Unix style line endings.
+ When using the Subversion repository it's easiest to configure the svn
+ client to convert automatically for you.
+ If however you are getting a message such as "This makefile was not generated
+ by Developer Studio etc.
+ etc.
+\begin_inset Quotes srd
+\end_inset
+
+ 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
+\begin_inset Quotes sld
+\end_inset
+
+unix2dos
+\begin_inset Quotes srd
+\end_inset
+
+ utility freely available on the internet.
+ Doug Hawkins reported in the sdcc-user list that this works:
+\newline
+
+\newline
+C:
+\backslash
+Programming
+\backslash
+SDCC> unix2dos sdcc.dsw
+\newline
+C:
+\backslash
+Programming
+\backslash
+SDCC> for /R %I in (*.dsp) do @unix2dos "%I"
+\newline
+
\newline
In order to build SDCC with MSVC you need win32 executables of bison.exe,
flex.exe, and gawk.exe.
from the sdcc directory.
\layout Subsection
-Windows Install Using a Binary Package
-\begin_inset LatexCommand \label{sub:Windows-Install}
-
-\end_inset
-
-
+Windows Install Using a ZIP Package
\layout Enumerate
-Download the binary package from
-\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/snap.php}
+Download the binary zip package from
+\begin_inset LatexCommand \url{http://sdcc.sf.net/snap.php}
\end_inset
Adjust your environment variable PATH to include the location of the bin
directory or start sdcc using the full path.
+\layout Subsection
+
+Windows Install Using the Setup Program
+\begin_inset LatexCommand \label{sub:Windows-Install}
+
+\end_inset
+
+
+\layout Standard
+
+Download the setup program
+\emph on
+sdcc-x.y.z-setup.exe
+\emph default
+ 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
+\emph on
+sdcc_yyyymmdd_setup.exe
+\emph default
+ from
+\begin_inset LatexCommand \url{http://sdcc.sf.net/snap.php}
+
+\end_inset
+
+ and execute it.
+ A windows typical installer will guide you through the installation process.
\layout Section
Building the Documentation
You're invited to make changes and additions to this manual (sdcc/doc/sdccman.ly
x).
Using LyX
-\begin_inset LatexCommand \url{www.lyx.org}
+\begin_inset LatexCommand \url{http://www.lyx.org}
\end_inset
as editor this is straightforward.
- If you want to avoid installing the tools you will have some success with
- a bootable Knoppix CD
-\begin_inset LatexCommand \url{http://www.knoppix.net}
-
-\end_inset
-
-.
Prebuilt documentation in html and pdf format is available from
-\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/snap.php}
+\begin_inset LatexCommand \url{http://sdcc.sf.net/snap.php}
\end_inset
\end_inset
.
- You'll find the pdf version at
-\begin_inset LatexCommand \url{http://sdcc.sourceforge.net/doc/sdccman.pdf}
+
+\newline
+You'll find the pdf version
+\begin_inset LatexCommand \index{PDF version of this document}
+
+\end_inset
+
+ 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
+\begin_inset LatexCommand \url{http://sdcc.sf.net/doc/sdccman.html/index.html}
\end_inset
currently matches SDCC for mcs51 and DS390 best and does give too few informati
on about f.e.
- Z80, PIC and HC08.
+ Z80, PIC14, PIC16 and HC08.
\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
-\begin_inset LatexCommand \url{www.opencores.org}
+\begin_inset LatexCommand \url{http://www.opencores.org}
\end_inset
a
\emph default
rray
-\begin_inset LatexCommand \index{fpga (field programmable gate array)}
+\begin_inset LatexCommand \index{FPGA (field programmable gate array)}
+
+\end_inset
+
+
+\begin_inset Quotes srd
+\end_inset
+
+ or
+\begin_inset LatexCommand \url{http://sf.net/projects/fpgac}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{FpgaC ((subset of) C to FPGA compiler)}
\end_inset
+
+\begin_inset Quotes sld
+\end_inset
+have you ever heard of an open source compiler that compiles a subset of
+ C for an FPGA?
\begin_inset Quotes srd
\end_inset
\layout Itemize
s51 - The ucSim 8051 simulator.
+ Not available on Win32 platforms.
\layout Itemize
sdcdb - The source debugger.
+ Not available on Win32 platforms.
\layout Itemize
packihx - A tool to pack (compress) Intel hex files.
\end_inset
- is a freeware, opensource simulator developed by Daniel Drotos (
-\begin_inset LatexCommand \url{mailto:drdani@mazsola.iit.uni-miskolc.hu}
-
-\end_inset
-
-).
+ is a freeware, opensource simulator developed by Daniel Drotos.
The simulator is built as part of the build process.
For more information visit Daniel's web site at:
\begin_inset LatexCommand \url{http://mazsola.iit.uni-miskolc.hu/~drdani/embedded/s51}
.
It currently supports the core mcs51, the Dallas DS80C390 and the Phillips
XA51 family.
+ S51 is currently not available on Win32 platfors.
\layout Subsection
sdcdb - Source Level Debugger
\end_inset
, but can be easily changed to use other simulators.
-
+ Sdcdb is currently not available on Win32 platfors.
\layout Chapter
Using SDCC
\family default
\shape default
-\begin_inset LatexCommand \index{srecord (tool)}
+\begin_inset LatexCommand \index{srecord (bin, hex, ... tool)}
\end_inset
).
Both formats are documented in the documentation of srecord
-\begin_inset LatexCommand \index{srecord (tool)}
+\begin_inset LatexCommand \index{srecord (bin, hex, ... tool)}
\end_inset
- An intermediate file containing debug information needed to create the
.cdb file (with -
\begin_inset ERT
-status Collapsed
+status Open
\layout Standard
\end_inset
-debug) containing debug information.
- The format is documented in cdbfileformat.pdf.
+ The format is documented in cdbfileformat.pdf
\layout Itemize
sourcefile.
\layout Standard
+\family sans
\series bold
sdcc -c _divsint.c
\layout Standard
+\family sans
\series bold
sdcc -c _divuint.c
\layout Standard
+\family sans
\series bold
sdcc -c _modsint.c
\layout Standard
+\family sans
\series bold
sdcc -c _moduint.c
\layout Standard
+\family sans
\series bold
sdcc -c _mulint.c
\newline
\layout Standard
+\family sans
\series bold
sdcclib libint.lib _divsint.rel
+\family default
+
\begin_inset LatexCommand \index{sdcclib}
\end_inset
\layout Standard
+\family sans
\series bold
sdcclib libint.lib _divuint.rel
\layout Standard
+\family sans
\series bold
sdcclib libint.lib _modsint.rel
\layout Standard
+\family sans
\series bold
sdcclib libint.lib _moduint.rel
\layout Standard
+\family sans
\series bold
sdcclib libint.lib _mulint.rel
\series default
\newline
+\family sans
\series bold
sdcclib -s libint.lib
+\family default
+
\begin_inset LatexCommand \index{sdcclib}
\end_inset
\newline
+
+\family typewriter
+\series default
_divsint.rel:
\layout Standard
-\series bold
+\family typewriter
__divsint_a_1_1
\layout Standard
-\series bold
+\family typewriter
__divsint_PARM_2
\layout Standard
-\series bold
+\family typewriter
__divsint
\newline
_divuint.rel:
\layout Standard
-\series bold
+\family typewriter
__divuint_a_1_1
\layout Standard
-\series bold
+\family typewriter
__divuint_PARM_2
\layout Standard
-\series bold
+\family typewriter
__divuint_reste_1_1
\layout Standard
-\series bold
+\family typewriter
__divuint_count_1_1
\layout Standard
-\series bold
+\family typewriter
__divuint
\newline
_modsint.rel:
\layout Standard
-\series bold
+\family typewriter
__modsint_a_1_1
\layout Standard
-\series bold
+\family typewriter
__modsint_PARM_2
\layout Standard
-\series bold
+\family typewriter
__modsint
\newline
_moduint.rel:
\layout Standard
-\series bold
+\family typewriter
__moduint_a_1_1
\layout Standard
-\series bold
+\family typewriter
__moduint_PARM_2
\layout Standard
-\series bold
+\family typewriter
__moduint_count_1_1
\layout Standard
-\series bold
+\family typewriter
__moduint
\newline
_mulint.rel:
\layout Standard
-\series bold
+\family typewriter
__mulint_PARM_2
\layout Standard
-\series bold
+\family typewriter
__mulint
+\family default
+\series bold
+
\newline
\layout Standard
-If the source files are compiled using --debug, the corresponding debug
- information file .adb will be include in the library file as well.
+If the source files are compiled using -
+\begin_inset ERT
+status Open
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-debug
+\begin_inset LatexCommand \index{-\/-debug}
+
+\end_inset
+
+, the corresponding debug information file .adb will be include in the library
+ file as well.
The library files created with sdcclib are plain text files, so they can
be viewed with a text editor.
It is not recomended to modify a library file created with sdcclib using
\series default
- Generate code for the Motorola HC08
+ Generate code for the Freescale/Motorola HC08
\begin_inset LatexCommand \index{HC08}
\end_inset
- family of processors (added Oct 2003).
+ family of processors.
\layout List
\labelwidthstring 00.00.0000
\end_inset
processor (In development, not complete).
- AVR users should probably have a look at avr-gcc
-\begin_inset LatexCommand \url{ http://savannah.nongnu.org/download/avr-libc/snapshots/}
+ AVR users should probably have a look at winavr
+\begin_inset LatexCommand \url{http://sourceforge.net/projects/winavr}
+
+\end_inset
+
+ or
+\begin_inset LatexCommand \url{http://www.avrfreaks.net/index.php?name=PNphpBB2&file=index}
\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.
-\layout List
-\labelwidthstring 00.00.0000
-
-
+ The
\series bold
-
\begin_inset ERT
/
\end_inset
--data-loc
+-pack-iram
\series default
-
-\begin_inset LatexCommand \index{-\/-data-loc <Value>}
-
-\end_inset
-
\SpecialChar ~
-<Value> The start location of the internal ram data
-\begin_inset LatexCommand \index{data (mcs51, ds390 storage class)}
+
+\begin_inset LatexCommand \index{-\/-pack-iram}
\end_inset
- segment.
- The value entered can be in Hexadecimal or Decimal format, eg.
- -
+ option (which is now a default setting) will override this setting, so
+ you should also specify the
+\series bold
+-
\begin_inset ERT
status Collapsed
/
\end_inset
--data-loc 0x20 or -
-\begin_inset ERT
-status Collapsed
+-no-pack-iram
+\series default
+\SpecialChar ~
-\layout Standard
+\begin_inset LatexCommand \index{-\/-no-pack-iram}
-\backslash
+\end_inset
+
+ option if you need to manually place the stack.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-xstack-loc
+\series default
+
+\begin_inset LatexCommand \index{-\/-xstack-loc <Value>}
+
+\end_inset
+
+\SpecialChar ~
+<Value> By default the external stack
+\begin_inset LatexCommand \index{xstack}
+
+\end_inset
+
+ is placed after the pdata segment.
+ Using this option the xstack can be placed anywhere in the external memory
+ space of the 8051.
+ The value entered can be in Hexadecimal or Decimal format, e.g.
+ -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-xstack-loc 0x8000 or -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-stack-loc 32768.
+ The provided value should not overlap any other memory areas such as the
+ pdata or xdata segment and with enough space for the current application.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-data-loc
+\series default
+
+\begin_inset LatexCommand \index{-\/-data-loc <Value>}
+
+\end_inset
+
+\SpecialChar ~
+<Value> The start location of the internal ram data
+\begin_inset LatexCommand \index{data (mcs51, ds390 storage class)}
+
+\end_inset
+
+ segment.
+ The value entered can be in Hexadecimal or Decimal format, eg.
+ -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-data-loc 0x20 or -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
/
\end_inset
This is the default option.
The format itself is documented in the documentation of srecord
-\begin_inset LatexCommand \index{srecord (tool)}
+\begin_inset LatexCommand \index{srecord (bin, hex, ... tool)}
\end_inset
\labelwidthstring 00.00.0000
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-out-fmt-elf
+\begin_inset LatexCommand \index{-\/-out-fmt-s19}
+
+\end_inset
+
+
+\bar under
+
+\series default
+\bar default
+The linker output (final object code) is in ELF format
+\begin_inset LatexCommand \index{ELF format}
+
+\end_inset
+
+.
+ (Currently only supported for the HC08 processors)
+\layout List
+\labelwidthstring 00.00.0000
+
+
\series bold
-Wl\SpecialChar ~
linkOption[,linkOption]
\labelwidthstring 00.00.0000
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-model-medium
+\begin_inset LatexCommand \index{-\/-model-medium}
+
+\end_inset
+
+
+\series default
+ Generate code for Medium model programs, see section Memory Models for
+ more details.
+ If this option is used all source files in the project have to be compiled
+ with this option.
+ It must also be used when invoking the linker.
+\layout List
+\labelwidthstring 00.00.0000
+
+
\series bold
-
\begin_inset ERT
details.
If this option is used all source files in the project have to be compiled
with this option.
+ It must also be used when invoking the linker.
\layout List
\labelwidthstring 00.00.0000
\end_inset
- Causes the linker use unused register banks for data variables or stack.
+ Causes the linker to use unused register banks for data variables and pack
+ data, idata and stack together.
+ This is the default now.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-no-pack-iram
+\series default
+\SpecialChar ~
+
+\begin_inset LatexCommand \index{-\/-no-pack-iram}
+
+\end_inset
+
+ Causes the linker to use old style for allocating memory areas.
\layout Subsection
DS390 / DS400 Options
\layout Subsection
-PIC Options
-\begin_inset LatexCommand \index{Options PIC}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{PIC options}
-
-\end_inset
-
-
-\layout List
-\labelwidthstring 00.00.0000
-
-
-\series bold
--
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
-
-\backslash
-/
-\end_inset
-
--gen-banksel
-\begin_inset LatexCommand \index{-\/-gen-banksel}
-
-\end_inset
-
-
-\series default
- enable the generation of banksel assembler directives in the PIC16
-\begin_inset LatexCommand \index{PIC16}
-
-\end_inset
-
- port.
-\layout Subsection
-
Z80 Options
\begin_inset LatexCommand \index{Options Z80}
\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.
+ temporaries (
+\emph on
+s
+\emph default
+pill
+\emph on
+loc
+\emph default
+ations, sloc
+\begin_inset LatexCommand \index{sloc (spill location)}
+
+\end_inset
+
+).
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\SpecialChar ~
\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 section Loop Invariants.
+ For more details of loop optimizations performed see Loop Invariants in
+ section
+\begin_inset LatexCommand \ref{sub:Loop-Optimizations}
+
+\end_inset
+
+.
It is recommended that this option NOT be used, #pragma\SpecialChar ~
noinvariant
\begin_inset LatexCommand \index{\#pragma noinvariant}
\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.
+ This saves a few bytes in code space if you don't have initialized data
+\begin_inset LatexCommand \index{Variable initialization}
+
+\end_inset
+
+.
\layout List
\labelwidthstring 00.00.0000
\series default
- Pass the inline assembler code through the peep hole optimizer.
+ 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}
rules defined in the source file tree '<target>/peeph.def' before using
this option.
-\layout Subsection
-
-Other Options
-\begin_inset LatexCommand \index{Options other}
-
-\end_inset
-
-
\layout List
\labelwidthstring 00.00.0000
\series bold
--c\SpecialChar ~
-
\begin_inset ERT
status Collapsed
/
\end_inset
--compile-only
-\begin_inset LatexCommand \index{-\/-compile-only}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{-c -\/-compile-only}
+-opt-code-speed
+\begin_inset LatexCommand \index{-\/-opt-code-speed}
\end_inset
\series default
- will compile and assemble the source, but will not call the linkage editor.
+ The compiler will optimize code generation towards fast code, possibly
+ at the expense of code size.
\layout List
\labelwidthstring 00.00.0000
\series bold
-
-\series default
-
\begin_inset ERT
status Collapsed
/
\end_inset
-
-\series bold
--c1mode
-\begin_inset LatexCommand \index{-\/-c1mode}
+-opt-code-size
+\begin_inset LatexCommand \index{-\/-opt-code-size}
\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.
-\layout List
-\labelwidthstring 00.00.0000
-
+ The compiler will optimize code generation towards compact code, possibly
+ at the expense of code speed.
+\layout Subsection
-\series bold
--E
-\begin_inset LatexCommand \index{-E}
+Other Options
+\begin_inset LatexCommand \index{Options other}
\end_inset
-\series default
- Run only the C preprocessor.
- Preprocess all the C source files specified and output the results to standard
- output.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-c\SpecialChar ~
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-compile-only
+\begin_inset LatexCommand \index{-\/-compile-only}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{-c -\/-compile-only}
+
+\end_inset
+
+
+\series default
+ will compile and assemble the source, but will not call the linkage editor.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\series default
+
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+
+\series bold
+-c1mode
+\begin_inset LatexCommand \index{-\/-c1mode}
+
+\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.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-E
+\begin_inset LatexCommand \index{-E}
+
+\end_inset
+
+
+\series default
+ Run only the C preprocessor.
+ Preprocess all the C source files specified and output the results to standard
+ output.
\layout List
\labelwidthstring 00.00.0000
\end_inset
.
- see section Parameters and Local Variables for more details.
+ 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 --int-long-reent and --float-reent.
\layout List
\labelwidthstring 00.00.0000
\series default
- This option can be used when the code generated is called by a monitor
- program.
- The compiler will generate a 'ret' upon return from the 'main'
+ 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 might result in slightly smaller code and save two bytes of
+ stack space.
+ The return from the 'main'
\begin_inset LatexCommand \index{main return}
\end_inset
- function.
+ function will return to the function calling main.
The default setting is to lock up i.e.
generate a '
\family typewriter
/
\end_inset
--nostdincl
-\begin_inset LatexCommand \index{-\/-nostdincl}
+-nostdinc
+\begin_inset LatexCommand \index{-\/-nostdinc}
\end_inset
\series default
Hides your ugly and inefficient c-code from the asm file, so you can always
- blame the compiler :).
+ blame the compiler :)
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-no-peep-comments
+\begin_inset LatexCommand \index{-\/-no-peep-comments}
+
+\end_inset
+
+
+\series default
+ Will not include peep-hole comments in the generated files.
\layout List
\labelwidthstring 00.00.0000
\end_inset
(jwk burps: please be more specific here, please!).
- If you want rather more than less warnings you should consider using a
- separate tool dedicated to syntax checking like splint
-\begin_inset LatexCommand \url{www.splint.org}
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+\backslash
+/
\end_inset
-.
+-disable-warning\SpecialChar ~
+<nnnn>
+\begin_inset LatexCommand \index{-\/-disable-warning}
+
+\end_inset
+
+
+\series default
+ Disable specific warning with number <nnnn>.
\layout List
\labelwidthstring 00.00.0000
\end_inset
.
- See file sdcc/as/doc/asxhtm.html for assembler options.
-\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
-
-
-\layout Standard
-
-The following options are provided for the purpose of retargetting and debugging
- the compiler.
- These provided 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
-
-.
+ See file sdcc/as/doc/asxhtm.html for assembler options.cd
\layout List
\labelwidthstring 00.00.0000
/
\end_inset
--dumpraw
-\begin_inset LatexCommand \index{-\/-dumpraw}
+-std-sdcc89
+\begin_inset LatexCommand \index{-\/-std-sdcc89}
\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}
-
-\end_inset
-
- at this stage ordered in the depth first number, so they may not be in
- sequence of execution.
+ Generally follow the C89 standard, but allow SDCC features that conflict
+ with the standard (default).
\layout List
\labelwidthstring 00.00.0000
/
\end_inset
--dumpgcse
-\begin_inset LatexCommand \index{-\/-dumpgcse}
+-std-c89
+\begin_inset LatexCommand \index{-\/-std-c89}
\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.
+ Follow the C89 standard and disable SDCC features that conflict with the
+ standard.
\layout List
\labelwidthstring 00.00.0000
/
\end_inset
--dumpdeadcode
-\begin_inset LatexCommand \index{-\/-dumpdeadcode}
+-std-sdcc99
+\begin_inset LatexCommand \index{-\/-std-sdcc99}
\end_inset
\series default
- Will create a dump of iCode's, after deadcode elimination
-\begin_inset LatexCommand \index{Dead-code elimination}
-
-\end_inset
-
-, into a file named
-\emph on
-<source filename>.dumpdeadcode.
+ Generally follow the C99 standard, but allow SDCC features that conflict
+ with the standard (incomplete support).
\layout List
\labelwidthstring 00.00.0000
/
\end_inset
--dumploop
-\begin_inset LatexCommand \index{-\/-dumploop}
+-std-c99
+\begin_inset LatexCommand \index{-\/-std-sdcc99}
\end_inset
\series default
-\size large
-
-\size default
-Will create a dump of iCode's, after loop optimizations
-\begin_inset LatexCommand \index{Loop optimization}
-
-\end_inset
-
-, into a file named
-\emph on
-<source filename>.dumploop.
+ Follow the C99 standard and disable SDCC features that conflict with the
+ standard (incomplete support).
\layout List
\labelwidthstring 00.00.0000
/
\end_inset
--dumprange
-\begin_inset LatexCommand \index{-\/-dumprange}
+-codeseg
+\series default
-\end_inset
+\begin_inset LatexCommand \index{-\/-codeseg <Value>}
+\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}
+\SpecialChar ~
+<Name> The name to be used for the code
+\begin_inset LatexCommand \index{code}
\end_inset
-, into a file named
-\emph on
-<source filename>.dumprange.
+ 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.
\layout List
\labelwidthstring 00.00.0000
/
\end_inset
--dumlrange
-\begin_inset LatexCommand \index{-\/-dumlrange}
+-constseg
+\series default
-\end_inset
+\begin_inset LatexCommand \index{-\/-constseg <Value>}
+\end_inset
-\series default
- Will dump the life ranges
-\begin_inset LatexCommand \index{Live range analysis}
+\SpecialChar ~
+<Name> The name to be used for the const
+\begin_inset LatexCommand \index{code}
\end_inset
- for all symbols.
+ 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.
\layout List
\labelwidthstring 00.00.0000
\series bold
--
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
+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}
-\backslash
-/
\end_inset
--dumpregassign
-\begin_inset LatexCommand \index{-\/-dumpregassign}
-\end_inset
+\begin_inset LatexCommand \index{lint (syntax checking tool)}
+\end_inset
-\bar under
-\series default
-\bar default
-Will create a dump of iCode's, after register assignment
-\begin_inset LatexCommand \index{Register assignment}
+\begin_inset LatexCommand \url{http://www.splint.org}
\end_inset
-, into a file named
-\emph on
-<source filename>.dumprassgn.
-\layout List
-\labelwidthstring 00.00.0000
-
-
-\series bold
--
-\begin_inset ERT
-status Collapsed
+.
+ To make your source files parseable by splint you will have to include
+
+\family sans
+lint.h
+\family default
-\layout Standard
+\begin_inset LatexCommand \index{splint (syntax checking tool)}
-\backslash
-/
\end_inset
--dumplrange
-\begin_inset LatexCommand \index{-\/-dumplrange}
+ in your source file and add brackets around extended keywords (like
+\family sans
+\begin_inset Quotes sld
\end_inset
+__at\SpecialChar ~
+\series bold
+(
+\series default
+0xab
+\series bold
+)
\series default
- Will create a dump of the live ranges of iTemp's
-\layout List
-\labelwidthstring 00.00.0000
+\begin_inset Quotes srd
+\end_inset
-\series bold
--
-\begin_inset ERT
-status Collapsed
-\layout Standard
+\family default
+ and
+\family sans
-\backslash
-/
+\begin_inset Quotes sld
\end_inset
--dumpall
-\begin_inset LatexCommand \index{-\/-dumpall}
-
+__interrupt\SpecialChar ~
+(2)
+\begin_inset Quotes srd
\end_inset
-\size large
-\bar under
+\family default
+).
-\series default
-\size default
-\bar default
-Will cause all the above mentioned dumps to be created.
+\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
+
+\family sans
+splint\SpecialChar ~
+-I\SpecialChar ~
+/usr/local/share/sdcc/include/mcs51/\SpecialChar ~
+\SpecialChar ~
+myprogram.c
\layout Subsection
-Redirecting output on Windows Shells
+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
+
+
\layout Standard
-By default SDCC writes it's error messages to
-\begin_inset Quotes sld
+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
-standard error
-\begin_inset Quotes srd
+) 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
-.
- To force all messages to
-\begin_inset Quotes sld
+
+\begin_inset Quotes srd
\end_inset
-standard output
+The anatomy of the compiler
\begin_inset Quotes srd
\end_inset
- use
+.
+\layout List
+\labelwidthstring 00.00.0000
+
+
\series bold
-
-\series default
-\emph on
-
\begin_inset ERT
status Collapsed
/
\end_inset
+-dumpraw
+\begin_inset LatexCommand \index{-\/-dumpraw}
+
+\end_inset
+
-\series bold
-\emph default
--
\series default
-use-stdout
-\begin_inset LatexCommand \index{-\/-use-stdout}
+ 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
-.
- 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
+ at this stage ordered in the depth first number, so they may not be in
+ sequence of execution.
+\layout List
+\labelwidthstring 00.00.0000
+
+\series bold
+-
\begin_inset ERT
status Collapsed
/
\end_inset
-
-\emph default
--vc
-\begin_inset LatexCommand \index{-\/-vc}
+-dumpgcse
+\begin_inset LatexCommand \index{-\/-dumpgcse}
\end_inset
- option.
- Something like this should work:
-\newline
-
-\newline
-\series bold
-c:
-\backslash
-sdcc
-\backslash
-bin
-\backslash
-sdcc.exe -
\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.
+\layout List
+\labelwidthstring 00.00.0000
+
+\series bold
+-
\begin_inset ERT
status Collapsed
/
\end_inset
+-dumpdeadcode
+\begin_inset LatexCommand \index{-\/-dumpdeadcode}
+
+\end_inset
+
-\series bold
-\emph default
--vc -
\series default
+ Will create a dump of iCode's, after deadcode elimination
+\begin_inset LatexCommand \index{Dead-code elimination}
+
+\end_inset
+
+, into a file named
\emph on
+<source filename>.dumpdeadcode.
+\layout List
+\labelwidthstring 00.00.0000
+
+\series bold
+-
\begin_inset ERT
status Collapsed
/
\end_inset
-
-\series bold
-\emph default
--model-large -c $(InputPath)
-\layout Section
-
-Environment variables
-\begin_inset LatexCommand \index{Environment variables}
+-dumploop
+\begin_inset LatexCommand \index{-\/-dumploop}
\end_inset
-\layout Standard
+\series default
+\size large
+
+\size default
+Will create a dump of iCode's, after loop optimizations
+\begin_inset LatexCommand \index{Loop optimization}
-SDCC recognizes the following environment variables:
+\end_inset
+
+, into a file named
+\emph on
+<source filename>.dumploop.
\layout List
\labelwidthstring 00.00.0000
\series bold
-SDCC_LEAVE_SIGNALS
-\begin_inset LatexCommand \index{SDCC\_LEAVE\_SIGNALS}
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-dumprange
+\begin_inset LatexCommand \index{-\/-dumprange}
\end_inset
\series default
- SDCC installs a signal handler
-\begin_inset LatexCommand \index{signal handler}
+\size large
+
+\size default
+Will create a dump of iCode's, after live range analysis
+\begin_inset LatexCommand \index{Live range analysis}
\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.
+, into a file named
+\emph on
+<source filename>.dumprange.
\layout List
\labelwidthstring 00.00.0000
\series bold
-TMP,\SpecialChar ~
-TEMP,\SpecialChar ~
-TMPDIR
-\begin_inset LatexCommand \index{TMP, TEMP, TMPDIR}
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-dumlrange
+\begin_inset LatexCommand \index{-\/-dumlrange}
+
+\end_inset
+
+
+\series default
+ Will dump the life ranges
+\begin_inset LatexCommand \index{Live range analysis}
+
+\end_inset
+
+ for all symbols.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-dumpregassign
+\begin_inset LatexCommand \index{-\/-dumpregassign}
+
+\end_inset
+
+
+\bar under
+
+\series default
+\bar default
+Will create a dump of iCode's, after register assignment
+\begin_inset LatexCommand \index{Register assignment}
+
+\end_inset
+
+, into a file named
+\emph on
+<source filename>.dumprassgn.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-dumplrange
+\begin_inset LatexCommand \index{-\/-dumplrange}
+
+\end_inset
+
+
+\series default
+ Will create a dump of the live ranges of iTemp's
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-dumpall
+\begin_inset LatexCommand \index{-\/-dumpall}
+
+\end_inset
+
+
+\size large
+\bar under
+
+\series default
+\size default
+\bar default
+Will cause all the above mentioned dumps to be created.
+\layout Subsection
+
+Redirecting output on Windows Shells
+\layout Standard
+
+By default SDCC writes it's error messages to
+\begin_inset Quotes sld
+\end_inset
+
+standard error
+\begin_inset Quotes srd
+\end_inset
+
+.
+ To force all messages to
+\begin_inset Quotes sld
+\end_inset
+
+standard output
+\begin_inset Quotes srd
+\end_inset
+
+ use
+\series bold
+-
+\series default
+\emph on
+
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+
+\series bold
+\emph default
+-
+\series default
+use-stdout
+\begin_inset LatexCommand \index{-\/-use-stdout}
+
+\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
+
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+
+\emph default
+-vc
+\begin_inset LatexCommand \index{-\/-vc}
+
+\end_inset
+
+ option.
+ Something like this should work:
+\newline
+
+\newline
+
+\series bold
+c:
+\backslash
+sdcc
+\backslash
+bin
+\backslash
+sdcc.exe -
+\series default
+\emph on
+
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+
+\series bold
+\emph default
+-vc -
+\series default
+\emph on
+
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+
+\series bold
+\emph default
+-model-large -c $(InputPath)
+\layout Section
+
+Environment variables
+\begin_inset LatexCommand \index{Environment variables}
+
+\end_inset
+
+
+\layout Standard
+
+SDCC recognizes the following environment variables:
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+SDCC_LEAVE_SIGNALS
+\begin_inset LatexCommand \index{SDCC\_LEAVE\_SIGNALS}
+
+\end_inset
+
+
+\series default
+ SDCC installs a signal handler
+\begin_inset LatexCommand \index{signal handler}
+
+\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.
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series bold
+TMP,\SpecialChar ~
+TEMP,\SpecialChar ~
+TMPDIR
+\begin_inset LatexCommand \index{TMP, TEMP, TMPDIR}
\end_inset
\end_inset
- / near
-\begin_inset LatexCommand \index{near (storage class)}
+
+\begin_inset LatexCommand \index{\_\_data (mcs51, ds390 storage class)}
+
+\end_inset
+
+ / near
+\begin_inset LatexCommand \index{near (storage class)}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_near (storage class)}
\end_inset
xdata
\begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_xdata (mcs51, ds390 storage class)}
+
\end_inset
/ far
\end_inset
+\begin_inset LatexCommand \index{\_\_far (storage class)}
+
+\end_inset
+
+
\layout Standard
Variables declared with this storage class will be placed in the external
\end_inset
+\begin_inset LatexCommand \index{\_\_idata (mcs51, ds390 storage class)}
+
+\end_inset
+
+
\layout Standard
Variables declared with this storage class will be allocated into the indirectly
\end_inset
+\begin_inset LatexCommand \index{\_\_pdata (mcs51, ds390 storage class)}
+
+\end_inset
+
+
\layout Standard
-Paged xdata access is currently not as straightforward as using the other
- addressing modes of a 8051.
- The following example writes 0x01 to the address pointed to.
+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
).
+ This is the
+\series bold
+default
+\series default
+ storage class for the Medium Memory model, e.g.:
\layout Verse
\family typewriter
-pdata unsigned char *test_pdata_ptr;
-\newline
-
-\newline
-void main()
-\newline
-{
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-test_pdata_ptr = (pdata *)0xfe;
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-*test_pdata_ptr = 1;
-\newline
-}
+pdata unsigned char test_pdata;
\layout Standard
-Generates the assembly code:
+Writing 0x01 to this variable generates the assembly code:
\layout Verse
\family typewriter
-75*01 FE\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-mov\SpecialChar ~
- _test_pdata_ptr,#0xFE
-\newline
-78 FE\SpecialChar ~
+78r00\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov\SpecialChar ~
- r0,#0xFE
+mov r0,#_test_pdata
\newline
74 01\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mov\SpecialChar ~
- a,#0x01
+mov a,#0x01
\newline
F2\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-movx @r0,a
+movx @r0,a
\layout Standard
-Be extremely carefull if you use pdata together with the -
+If the -
\begin_inset ERT
status Collapsed
\end_inset
- option.
+ 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.
\layout Subsubsection
code
\end_inset
+\begin_inset LatexCommand \index{\_\_code}
+
+\end_inset
+
+
\layout Standard
'Variables' declared with this storage class will be placed in the code
\end_inset
+\begin_inset LatexCommand \index{\_\_bit}
+
+\end_inset
+
+
\layout Standard
This is a data-type and a storage class specifier.
The bit addressable memory consists of 128 bits which are located from 0x20
to 0x2f in data memory.
-\layout Standard
-
+\newline
Apart from this 8051 specific storage class most architectures support ANSI-C
bitfields
\begin_inset LatexCommand \index{bitfields}
\end_inset
-
+
\begin_inset Foot
collapsed false
\end_inset
.
+ In accordance with ISO/IEC 9899 bits and bitfields without an explicit
+ signed modifier are implemented as unsigned.
\layout Subsubsection
sfr
\begin_inset LatexCommand \index{sfr}
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_sfr}
+
+\end_inset
+
+ / sfr16
+\begin_inset LatexCommand \index{sfr16}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_sfr16}
+
+\end_inset
+
+ / sfr32
+\begin_inset LatexCommand \index{sfr32}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_sfr32}
+
\end_inset
/ sbit
-\begin_inset LatexCommand \index{sbit}
+\begin_inset LatexCommand \index{\_\_sbit}
\end_inset
Like the bit keyword,
\emph on
-sfr / sbit
+sfr / sfr16 / sfr32 / sbit
\emph default
-signifies both a data-type and storage class, they are used to describe
- the
+signify both a data-type and storage class, they are used to describe the
+
\emph on
s
\emph default
sfr at
\begin_inset LatexCommand \index{at}
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_at}
+
\end_inset
0x80 P0;\SpecialChar ~
/* special function register P0 at location 0x80 */
\newline
+/* 16 bit special function register combination for timer 0 */
+\newline
+/* with the high byte at location 0x8C and the low byte at location 0x8A
+ */
+\newline
+sfr16 at
+\begin_inset LatexCommand \index{at}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_at}
+
+\end_inset
+
+ 0x8C8A TMR0;
+\newline
sbit at 0xd7 CY; /* CY (Carry Flag
\begin_inset LatexCommand \index{Flags}
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.
\layout Subsubsection
Pointers
*/
\newline
char * xdata p;
+\newline
+
+\newline
+/* the following is a function pointer physically located in data space
+ */
+\newline
+char (* data fp)(void);
\layout Standard
Well you get the idea.
\end_inset
+
+\begin_inset LatexCommand \index{\_\_idata (mcs51, ds390 storage class)}
+
+\end_inset
+
).
Furthermore, some chips may have some built in external memory (
\emph on
\end_inset
+
+\begin_inset LatexCommand \index{\_\_xdata (mcs51, ds390 storage class)}
+
+\end_inset
+
) which should not be confused with the internal, directly addressable RAM
memory (
\emph on
\end_inset
+
+\begin_inset LatexCommand \index{\_\_data (mcs51, ds390 storage class)}
+
+\end_inset
+
).
Sometimes this built in
\emph on
\end_inset
of registers (register bank 0), but it is possible to specify that other
- banks of registers should be used in interrupt
+ banks of registers (keyword
+\emph on
+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
+) should be used in interrupt
\begin_inset LatexCommand \index{interrupt}
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_interrupt}
+
\end_inset
routines.
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 after
- the byte holding the last bit variable.
+ 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 at address 0x22.
+ 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>}
+\begin_inset LatexCommand \index{-\/-data-loc <Value>}
\end_inset
/
\end_inset
--iram-size to specify the size of the total internal RAM (
+-iram-size
+\begin_inset LatexCommand \index{-\/-iram-size <Value>}
+
+\end_inset
+
+ to specify the size of the total internal RAM (
\emph on
data
\emph default
\layout Standard
-By default the 8051 linker will place the stack after the last byte of data
+By default the 8051 linker will place the stack after the last byte of (i)data
variables.
Option -
\begin_inset ERT
\end_inset
-stack-loc
-\begin_inset LatexCommand \index{-\/-stack-loc<Value>}
+\begin_inset LatexCommand \index{-\/-stack-loc <Value>}
\end_inset
\end_inset
-xram-size
-\begin_inset LatexCommand \index{-\/-data-loc}
+\begin_inset LatexCommand \index{-\/-xram-size <Value>}
\end_inset
\end_inset
-code-loc
-\begin_inset LatexCommand \index{-\/-data-loc}
+\begin_inset LatexCommand \index{-\/-code-loc <Value>}
\end_inset
\end_inset
-code-size
-\begin_inset LatexCommand \index{-\/-data-loc}
+\begin_inset LatexCommand \index{-\/-code-size <Value>}
\end_inset
sfr
\begin_inset LatexCommand \index{sfr}
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_sfr}
+
\end_inset
(in/out to 8-bit addresses)
banked sfr
\begin_inset LatexCommand \index{sfr}
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_sfr}
+
\end_inset
(in/out to 16-bit addresses)
sfr banked at
\begin_inset LatexCommand \index{at}
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_at}
+
\end_inset
0x123 IoPort;
sfr
\begin_inset LatexCommand \index{sfr}
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_sfr}
+
\end_inset
(in0/out0 to 8 bit addresses on Z180
\layout Subsubsection
data
-\begin_inset LatexCommand \index{data (mcs51, ds390 storage class)}
+\begin_inset LatexCommand \index{data (hc08 storage class)}
\end_inset
+\begin_inset LatexCommand \index{\_\_data (hc08 storage class)}
+
+\end_inset
+
+
\layout Standard
The data storage class declares a variable that resides in the first 256
\layout Subsubsection
xdata
-\begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
+\begin_inset LatexCommand \index{xdata (hc08 storage class)}
\end_inset
+\begin_inset LatexCommand \index{\_\_xdata (hc08 storage class)}
+
+\end_inset
+
+
\layout Standard
The xdata storage class declares a variable that can reside anywhere in
at
\begin_inset LatexCommand \index{at}
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_at}
+
\end_inset
<address>
xdata
\begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_xdata (mcs51, ds390 storage class)}
+
\end_inset
at
\begin_inset LatexCommand \index{at}
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_at}
+
\end_inset
0x7ffe unsigned int chksum;
\layout Standard
-In the above example the variable chksum will located at 0x7ffe and 0x7fff
+In the above example the variable chksum will be located at 0x7ffe and 0x7fff
of the external ram.
The compiler does
\emph on
\emph on
volatile
\emph default
- should be used to tell the compiler that accesses might not be optimized
- away:
+ has to be used to tell the compiler that accesses might not be removed:
\layout Verse
\family typewriter
-extern volatile bit SDI;
+extern volatile
+\begin_inset LatexCommand \index{volatile}
+
+\end_inset
+
+ bit MOSI;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* master out, slave in */
\newline
-extern volatile bit SCLK;
+extern volatile bit MISO;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* master in, slave out */
\newline
-extern volatile bit CPOL;
+extern volatile bit MCLK;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* master clock */
\newline
\newline
-void DS1306_put(unsigned char value)
-\newline
-{
+/* Input and Output of a byte on a 3-wire serial bus.
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+If needed adapt polarity of clock, polarity of data and bit order
+\newline
\SpecialChar ~
-unsigned char mask=0x80;
+*/
\newline
-
+unsigned char spi_io(unsigned char out_byte)
+\newline
+{
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-while(mask)
+unsigned char i=8;
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-{
+do {
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-SDI=(value & mask)?1:0;
+MOSI = out_byte & 0x80;
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-SCLK=!CPOL;
+out_byte <<= 1;
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-SCLK=CPOL;
+MCLK = 1;
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mask/=2;
-\newline
+/* _asm nop _endasm; */\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-}
-\newline
-}
-\layout Standard
-
-Then, someplace in the code for the first hardware you would use
-\layout Verse
-
-
-\family typewriter
-bit at 0x80 SDI;\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-/* I/O port 0, bit 0 */
+/* for slow peripherals */
\newline
-bit at 0x81 SCLK;\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-/* I/O port 0, bit 1 */
-\newline
-bit CPOL;\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+if(MISO)
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-/* This is a variable, let the linker allocate this one */
-\layout Standard
-
-Similarly, for the second hardware you would use
-\layout Verse
-
-
-\family typewriter
-bit at 0x83 SDI;\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-/* I/O port 0, bit 3 */
-\newline
-bit at 0x91 SCLK;\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-/* I/O port 1, bit 1 */
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+out_byte += 1;
\newline
-bit
-\begin_inset LatexCommand \index{bit}
-
-\end_inset
-
- CPOL;\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+MCLK = 0;
+\newline
\SpecialChar ~
\SpecialChar ~
-/* This is a variable, let the linker allocate this one */
-\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
+\SpecialChar ~
+\SpecialChar ~
+} while(--i);
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+return out_byte;
+\newline
+}
+\layout Standard
+
+Then, someplace in the code for the first hardware you would use
+\layout Verse
+
+
+\family typewriter
+bit at
+\begin_inset LatexCommand \index{at}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_at}
+
+\end_inset
+
+ 0x80 MOSI;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* I/O port 0, bit 0 */
+\newline
+bit at 0x81 MISO;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* I/O port 0, bit 1 */
+\newline
+bit at 0x82 MCLK;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* I/O port 0, bit 2 */
+\layout Standard
+
+Similarly, for the second hardware you would use
+\layout Verse
+
+
+\family typewriter
+bit at 0x83 MOSI;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* I/O port 0, bit 3 */
+\newline
+bit at 0x91 MISO;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* I/O port 1, bit 1 */
+\newline
+bit
+\begin_inset LatexCommand \index{bit}
+
+\end_inset
+
+ at 0x92 MCLK;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* I/O port 1, bit 2 */
+\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.
\layout Section
\end_inset
+\begin_inset LatexCommand \label{sec:Parameters-and-Local-Variables}
+
+\end_inset
+
+
\layout Standard
Automatic (local) variables and parameters to functions can either be placed
\end_inset
- either by using the
+ by using the
\emph on
-
\begin_inset ERT
\emph default
- option or by using the
+ option, by using
+\emph on
+#pragma\SpecialChar ~
+stackauto
+\emph default
+
+\begin_inset LatexCommand \index{\#pragma stackauto}
+
+\end_inset
+
+ or by using the
\emph on
reentrant
\begin_inset LatexCommand \index{reentrant}
, (storage classes for parameters will be ignored), their allocation is
governed by the memory model in use, and the reentrancy options.
+\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 as a single byte just like the normal
+ registers.
\layout Section
Overlaying
\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
main
\emph default
.
- The
+ The optional
\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
keyword can be used to tell the compiler to use the specified register
bank (8051 specific) when generating code for this function.
\layout Standard
Interrupt service routines open the door for some very interesting bugs:
-
-\layout Standard
-
-If the interrupt service routines changes variables which are accessed by
- other functions these variables should be declared
+\newline
+If an interrupt service routine changes variables which are accessed by
+ other functions these variables have to be declared
\emph on
volatile
\emph default
If the access to these variables is not
\emph on
atomic
-\begin_inset LatexCommand \index{atomic access}
+\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 disabled
+ be interrupted while accessing the variable) the interrupt must be disabled
during the access to avoid inconsistent data.
Access to 16 or 32 bit variables is obviously not atomic on 8 bit CPUs
and should be protected by disabling interrupts.
\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.
+\layout Standard
+
A special note here, int (16 bit) and long (32 bit) integer division
\begin_inset LatexCommand \index{Division}
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
\newline
\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
\end_inset
for details on customizing startup.
+\layout Subsection
+
+Z80 Interrupt Service Routines
+\layout Standard
+
+The Z80 uses several different methods for determining the correct interrupt
+ vector depending on the hardware implementation.
+ Therefore, SDCC ignores the optional interrupt number and does not attempt
+ to generate an interrupt vector table.
+\layout Standard
+
+By default, SDCC generates code for a maskable interrupt, which uses an
+ RETI instruction to return from the interrupt.
+ To write an interrupt handler for the non-maskable interrupt, which needs
+ an RETN instruction instead, add the
+\emph on
+critical
+\emph default
+ keyword:
+\layout Verse
+
+
+\family typewriter
+void nmi_isr (void) critical interrupt
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+...
+
+\newline
+}
\layout Section
Enabling and Disabling Interrupts
\end_inset
+
+\begin_inset LatexCommand \index{\_\_critical}
+
+\end_inset
+
\newline
{
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.
- Don't add complexity unless you have to.
+ Check there is sufficient space on the stack
+\begin_inset LatexCommand \index{stack}
+
+\end_inset
+
+ and don't add complexity unless you have to.
+
+\layout Subsection
+
+Semaphore
+\begin_inset LatexCommand \index{semaphore}
+
+\end_inset
+
+ locking (mcs51/ds390)
+\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.
+
+\layout Standard
+
+SDCC generates this instruction if the source follows this pattern:
+\layout Verse
+
+
+\family typewriter
+volatile
+\begin_inset LatexCommand \index{volatile}
+
+\end_inset
+
+ bit resource_is_free;
+\newline
+
+\newline
+if (resource_is_free)
+\newline
+\SpecialChar ~
+\SpecialChar ~
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+resource_is_free=0;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+...
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+resource_is_free=1;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+}
+\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).
\layout Section
Functions using private register banks
\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)}
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
\emph default
routine to your program to override the default if you need to setup hardware
or perform some other critical operation prior to static & global variable
- initialization.
- On some mcs51 variants xdata has to be explicitly enabled before it can
- be accessed, this is the place to do it.
- See also the compiler option
+ initialization
+\begin_inset LatexCommand \index{Variable initialization}
+
+\end_inset
+
+.
+ On some mcs51 variants xdata
+\begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
+
+\end_inset
+
+ memory has to be explicitly enabled before it can be accessed or if the
+ watchdog 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
\emph on
-
\begin_inset ERT
/
\end_inset
--no-xinit
-\emph default
--
-\emph on
-opt
-\emph default
-
-\begin_inset LatexCommand \index{-\/-no-xinit-opt}
+-iram-size
+\begin_inset LatexCommand \index{-\/-iram-size <Value>}
\end_inset
- and section
-\begin_inset LatexCommand \ref{sub:MCS51-variants}
+n
+\emph default
+ is used.
+ (recommended for Chipcon CC1010).
+\layout Standard
+
+See also the compiler option
+\emph on
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-no-xinit
+\emph default
+-
+\emph on
+opt
+\emph default
+
+\begin_inset LatexCommand \index{-\/-no-xinit-opt}
+
+\end_inset
+
+ and section
+\begin_inset LatexCommand \ref{sub:MCS51-variants}
\end_inset
unsigned char far
\begin_inset LatexCommand \index{far (storage class)}
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_far (storage class)}
+
\end_inset
at
\begin_inset LatexCommand \index{at}
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_at}
+
\end_inset
0x7f00 buf[0x100];
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-buf[ head++ ] = c;
+buf[ head++ ] = c;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* access to a 256 byte aligned array */
\newline
}
\layout Standard
\end_inset
+\begin_inset LatexCommand \index{\_\_asm}
+
+\end_inset
+
+
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-_endasm;
+_endasm
+\begin_inset LatexCommand \index{\_endasm}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_endasm}
+
+\end_inset
+
+;
\newline
}
\layout Standard
\end_inset
+\begin_inset LatexCommand \index{\_\_asm}
+
+\end_inset
+
+
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-_endasm;
+_endasm
+\begin_inset LatexCommand \index{\_endasm}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_endasm}
+
+\end_inset
+
+;
\newline
}
\newline
The assembler does not like some characters like ':' or ''' in comments.
You'll find an 100+ pages assembler manual in sdcc/as/doc/asxhtm.html
+\begin_inset LatexCommand \index{asXXXX (as-gbz80, as-hc08, asx8051, as-z80)}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Assembler documentation}
+
+\end_inset
+
+
\end_inset
.
_asm
\begin_inset LatexCommand \index{\_asm}
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_asm}
+
\end_inset
...
- _endasm;
+ _endasm
+\size footnotesize
+
+\begin_inset LatexCommand \index{\_endasm}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_endasm}
+
+\end_inset
+
+
+\size default
+;
\family default
keyword pair.
Specifically it will not know which registers are used and thus register
\end_inset
+
+\begin_inset LatexCommand \index{\_\_naked}
+
+\end_inset
+
.
\emph default
void simpleInterrupt(void) interrupt
\begin_inset LatexCommand \index{interrupt}
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_interrupt}
+
\end_inset
1
\end_inset
+\begin_inset LatexCommand \index{\_\_asm}
+
+\end_inset
+
+
\newline
\SpecialChar ~
\SpecialChar ~
\end_inset
+
+\begin_inset LatexCommand \index{\_\_endasm}
+
+\end_inset
+
;
\newline
}
\end_inset
+
+\begin_inset LatexCommand \index{\_\_asm}
+
+\end_inset
+
\newline
\SpecialChar ~
_endasm
\begin_inset LatexCommand \index{\_endasm}
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_endasm}
+
\end_inset
;
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-_endasm ;
+_endasm
+\begin_inset LatexCommand \index{\_endasm}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_endasm}
+
+\end_inset
+
+ ;
\newline
\SpecialChar ~
\SpecialChar ~
\begin_inset Tabular
<lyxtabular version="3" rows="11" columns="2">
<features>
-<column alignment="center" valignment="top" leftline="true" width="0(null)">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0(null)">
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
<row topline="true" bottomline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\begin_inset Tabular
<lyxtabular version="3" rows="17" columns="2">
<features>
-<column alignment="center" valignment="top" leftline="true" width="0(null)">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0(null)">
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
<row topline="true" bottomline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
These support routines are developed in ANSI-C so there is room for space
- and speed improvement.
+ and speed improvement
+\begin_inset Foot
+collapsed false
+
+\layout Standard
+
+The floating point routines for the mcs51 are implemented in assembler
+\end_inset
+
+.
Note if all these routines are used simultaneously the data space might
overflow.
- For serious floating point usage it is recommended that the large model
- be used.
+ For serious floating point usage the large model might be needed.
Also notice that you don't have to call this routines directly.
The compiler will use them automatically every time a floating point operation
is required.
in sdcc/device/lib.
\layout Standard
+The default
+\family typewriter
+ printf()
+\begin_inset LatexCommand \index{printf()}
+
+\end_inset
+
+
+\family default
+implementation in
+\family typewriter
+ printf_large.c
+\family default
+ does not support float (except on ds390).
+ To enable this recompile it with the option
+\emph on
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+DUSE_FLOATS=1
+\begin_inset LatexCommand \index{USE\_FLOATS}
+
+\end_inset
+
+
+\emph default
+ on the command line.
+ Use
+\emph on
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-model-large
+\begin_inset LatexCommand \index{-\/-model-large}
+
+\end_inset
+
+
+\emph default
+ for the mcs51 port, since this uses a lot of memory.
+\layout Standard
+
If you're short on memory you might want to use
\family typewriter
printf_small()
+\begin_inset LatexCommand \index{printf\_small()}
+
+\end_inset
+
+
\family default
\emph on
\emph default
of
\family typewriter
- printf()
-\begin_inset LatexCommand \index{printf()}
+ printf().
+
+\family default
+ For the mcs51 there additionally are assembly versions
+\family typewriter
+printf_tiny()
+\begin_inset LatexCommand \index{printf\_tiny() (mcs51)}
\end_inset
-.
\family default
- For the mcs51 there is an assembly version
+ and
\family typewriter
printf_fast()
+\begin_inset LatexCommand \index{printf\_fast() (mcs51)}
+
+\end_inset
+
+
+\family default
+and
+\family typewriter
+ printf_fast_f()
+\begin_inset LatexCommand \index{printf\_fast\_f() (mcs51)}
+
+\end_inset
+
+
\family default
- which should fit the requirements of many embedded systems (by unsetting
- #defines it can be customized to
+ which should fit the requirements of many embedded systems (printf_fast()
+ can be customized by unsetting #defines to
\emph on
not
\emph default
\layout Subsubsection
-Small and Large
+Small, Medium and Large
\layout Standard
-SDCC allows two memory models for MCS51 code,
+SDCC allows three memory models for MCS51 code,
\shape slanted
-small
+small, medium
\shape default
and
\shape slanted
never
\emph default
be combined together or the results would be unpredictable.
- The library routines supplied with the compiler are compiled as both small
- and large.
- The compiled library modules are contained in separate directories as small
- and large so that you can link to either set.
-
+ The library routines supplied with the compiler are compiled as small,
+ medium and large.
+ The compiled library modules are contained in separate directories as small,
+ medium and large so that you can link to the appropriate set.
\layout Standard
-When the large model is used all variables declared without a storage class
- will be allocated into the external ram, this includes all parameters and
- local variables (for non-reentrant
+When the medium or large model is used all variables declared without a
+ storage class will be allocated into the external ram, this includes all
+ parameters and local variables (for non-reentrant
\begin_inset LatexCommand \index{reentrant}
\end_inset
\end_inset
- memory (usually at the start of the external ram segment) and is 256 bytes
- in size.
+ memory (usually at the start of the external ram segment) and uses all
+ unused space in pdata (max.
+ 256 bytes).
When -
\begin_inset ERT
status Collapsed
option, all parameters and local variables are allocated on the external
stack (note: support libraries will need to be recompiled with the same
- options).
+ options.
+ There is a predefined target in the library makefile).
\layout Standard
The compiler outputs the higher order address byte of the external ram segment
\end_inset
- this will save all current options to the save/restore stack.
- See restore.
+ See #pragma\SpecialChar ~
+restore.
\layout Itemize
restore
saves & restores can be nested.
SDCC uses a save/restore stack: save pushes current options to the stack,
restore pulls current options from the stack.
- See save.
+ See #pragma\SpecialChar ~
+save.
+\newline
+
\layout Itemize
-nogcse
-\begin_inset LatexCommand \index{\#pragma nogcse}
+callee_saves
+\begin_inset LatexCommand \index{\#pragma callee\_saves}
\end_inset
- - will stop global common subexpression elimination.
-\layout Itemize
-noinduction
-\begin_inset LatexCommand \index{\#pragma noinduction}
+\begin_inset LatexCommand \index{function prologue}
\end_inset
- - will stop loop induction optimizations.
-\layout Itemize
+ 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
+\begin_inset LatexCommand \index{push/pop}
-nojtbound
-\begin_inset LatexCommand \index{\#pragma nojtbound}
+\end_inset
+
+ when calling small functions from larger functions.
+ 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.
+ In the future the compiler (with inter procedural analysis) may be able
+ to determine the appropriate scheme to use for each function call.
+ If -
+\begin_inset ERT
+status Collapsed
+\layout Standard
+
+\backslash
+/
\end_inset
- - will not generate code for boundary value checking, when switch statements
- are turned into jump-tables (dangerous).
- For more details see section
-\begin_inset LatexCommand \ref{sub:'switch'-Statements}
+-callee-saves command line option is used, the function names specified
+ in #pragma\SpecialChar ~
+callee_saves
+\begin_inset LatexCommand \index{\#pragma callee\_saves}
\end_inset
-.
+ is appended to the list of functions specified in the command line.
\layout Itemize
-nooverlay
-\begin_inset LatexCommand \index{\#pragma nooverlay}
+exclude
+\begin_inset LatexCommand \index{\#pragma exclude}
\end_inset
- - the compiler will not overlay the parameters and local variables of a
- function.
+ none | {acc[,b[,dpl[,dph]]] - The exclude pragma disables the generation
+ of pairs of push/pop
+\begin_inset LatexCommand \index{push/pop}
+
+\end_inset
+
+ instructions in
+\emph on
+I
+\emph default
+nterrupt
+\begin_inset LatexCommand \index{interrupt}
+
+\end_inset
+
+
+\emph on
+S
+\emph default
+ervice
+\emph on
+R
+\emph default
+outines.
+ The directive should be placed immediately before the ISR function definition
+ and it affects ALL ISR functions following it.
+ To enable the normal register saving for ISR functions use #pragma\SpecialChar ~
+exclude\SpecialChar ~
+none
+\begin_inset LatexCommand \index{\#pragma exclude}
+
+\end_inset
+
+.
+ See also the related keyword _naked
+\begin_inset LatexCommand \index{\_naked}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{\_\_naked}
+
+\end_inset
+
+.
\layout Itemize
less_pedantic
your own now ;-(
\layout Itemize
-noloopreverse
-\begin_inset LatexCommand \index{\#pragma noloopreverse}
+disable_warning <nnnn>
+\begin_inset LatexCommand \index{\#pragma disable\_warning}
\end_inset
- - Will not do loop reversal optimization
+ - the compiler will not warn you anymore about warning number <nnnn>.
\layout Itemize
-exclude
-\begin_inset LatexCommand \index{\#pragma exclude}
+nogcse
+\begin_inset LatexCommand \index{\#pragma nogcse}
\end_inset
- none | {acc[,b[,dpl[,dph]]] - The exclude pragma disables generation of
- pair of push/pop
-\begin_inset LatexCommand \index{push/pop}
+ - will stop global common subexpression elimination.
+\layout Itemize
+
+noinduction
+\begin_inset LatexCommand \index{\#pragma noinduction}
\end_inset
- instruction in ISR function (using interrupt
-\begin_inset LatexCommand \index{interrupt}
+ - will stop loop induction optimizations.
+\layout Itemize
+
+noinvariant
+\begin_inset LatexCommand \index{\#pragma noinvariant}
\end_inset
- keyword).
- The directive should be placed immediately before the ISR function definition
- and it affects ALL ISR functions following it.
- To enable the normal register saving for ISR functions use #pragma\SpecialChar ~
-exclude\SpecialChar ~
-none
-\begin_inset LatexCommand \index{\#pragma exclude}
+ - will not do loop invariant optimizations.
+ For more details see Loop Invariants in section
+\begin_inset LatexCommand \ref{sub:Loop-Optimizations}
\end_inset
about interrupts.
\layout Itemize
-callee_saves
-\begin_inset LatexCommand \index{\#pragma callee\_saves}
+nojtbound
+\begin_inset LatexCommand \index{\#pragma nojtbound}
\end_inset
+ - will not generate code for boundary value checking, when switch statements
+ are turned into jump-tables (dangerous).
+ For more details see section
+\begin_inset LatexCommand \ref{sub:'switch'-Statements}
-\begin_inset LatexCommand \index{function prologue}
+\end_inset
+
+.
+\layout Itemize
+
+noloopreverse
+\begin_inset LatexCommand \index{\#pragma noloopreverse}
\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
-\begin_inset LatexCommand \index{push/pop}
+ - Will not do loop reversal optimization
+\layout Itemize
+
+nooverlay
+\begin_inset LatexCommand \index{\#pragma nooverlay}
\end_inset
- when calling small functions from larger functions.
- 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.
- In the future the compiler (with inter procedural analysis) may be able
- to determine the appropriate scheme to use for each function call.
- If -
+ - the compiler will not overlay the parameters and local variables of a
+ function.
+\layout Itemize
+
+stackauto
+\begin_inset LatexCommand \index{\#pragma stackauto}
+
+\end_inset
+
+- See option -
\begin_inset ERT
status Collapsed
/
\end_inset
--callee-saves command line option is used, the function names specified
- in #pragma\SpecialChar ~
-callee_saves
-\begin_inset LatexCommand \index{\#pragma callee\_saves}
+-stack-auto
+\begin_inset LatexCommand \index{-\/-stack-auto}
\end_inset
- is appended to the list of functions specified in the command line.
+ and section
+\begin_inset LatexCommand \ref{sec:Parameters-and-Local-Variables}
+
+\end_inset
+
+ Parameters and Local Variables.
+\layout Itemize
+
+opt_code_speed
+\begin_inset LatexCommand \index{\#pragma opt\_code\_speed}
+
+\end_inset
+
+- The compiler will optimize code generation towards fast code, possibly
+ at the expense of code size.
+\layout Itemize
+
+opt_code_size
+\begin_inset LatexCommand \index{\#pragma opt\_code\_size}
+
+\end_inset
+
+- The compiler will optimize code generation towards compact code, possibly
+ at the expense of code speed.
+\layout Itemize
+
+opt_code_balanced
+\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).
+
+\layout Itemize
+
+std_sdcc89
+\begin_inset LatexCommand \index{\#pragma std\_sdcc89}
+
+\end_inset
+
+- Generally follow the C89 standard, but allow SDCC features that conflict
+ with the standard (default).
+\layout Itemize
+
+std_c89
+\begin_inset LatexCommand \index{\#pragma std\_c89}
+
+\end_inset
+
+- Follow the C89 standard and disable SDCC features that conflict with the
+ standard.
+\layout Itemize
+
+std_sdcc99
+\begin_inset LatexCommand \index{\#pragma std\_sdcc99}
+
+\end_inset
+
+- Generally follow the C99 standard, but allow SDCC features that conflict
+ with the standard (incomplete support).
+\layout Itemize
+
+std_c99
+\begin_inset LatexCommand \index{\#pragma std\_c99}
+
+\end_inset
+
+- Follow the C99 standard and disable SDCC features that conflict with the
+ standard (incomplete support).
+\layout Itemize
+
+codeseg <name>
+\begin_inset LatexCommand \index{\#pragma codeseg}
+
+\end_inset
+
+- Use this name (max.
+ 8 characters) for the code segment.
+\layout Itemize
+
+constseg <name>
+\begin_inset LatexCommand \index{\#pragma constseg}
+
+\end_inset
+
+- Use this name (max.
+ 8 characters) for the const segment.
\layout Standard
SDCPP supports the following #pragma directives:
\begin_inset Tabular
-<lyxtabular version="3" rows="10" columns="2">
+<lyxtabular version="3" rows="11" columns="2">
<features>
-<column alignment="center" valignment="top" leftline="true" width="0(null)">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0(null)">
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
<row topline="true" bottomline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
+SDCC_MODEL_MEDIUM
+\begin_inset LatexCommand \index{SDCC\_MODEL\_MEDIUM}
+
+\end_inset
+
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+when
+\emph on
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-model-medium
+\emph default
+ is used
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
SDCC_MODEL_LARGE
\begin_inset LatexCommand \index{SDCC\_MODEL\_LARGE}
\emph default
is where the chip designers decided to put it.
Needless to say that they didn't agree on a common name either.
- As pdata addressing is used in the startup code for the initialization
- of xdata variables a separate startup code should be used as described
- in section
+ So that the startup code can correctly initialize xdata variables, you
+ should define an sfr with the name _XPAGE
+\family typewriter
+
+\begin_inset LatexCommand \index{\_XPAGE (mcs51)}
+
+\end_inset
+
+
+\family default
+ at the appropriate location if the default, port P2, is not used for this.
+ Some examples are:
+\layout Verse
+
+
+\family typewriter
+sfr at 0x92 _XPAGE; /* Cypress EZ-USB family */
+\layout Verse
+
+
+\family typewriter
+sfr at 0xaf _XPAGE; /* some Silicon Labs (Cygnal) chips */
+\layout Verse
+
+
+\family typewriter
+sfr at 0xaa _XPAGE; /* some Silicon Labs (Cygnal) chips */
+\layout Standard
+
+For more exotic implementations further customizations may be needed.
+ See section
\begin_inset LatexCommand \ref{sub:Startup-Code}
\end_inset
-.
+ for other possibilities.
\layout Subsection
Other Features available by SFR
a patch to SDCC.
\layout Section
+DS400 port
+\layout Standard
+
+The DS80C400 microcontroller has a rich set of peripherals.
+ 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
+\size footnotesize
+
+\begin_inset LatexCommand \url{ftp://ftp.dalsemi.com/pub/tini/ds80c400/c_libraries/sdcc/index.html}
+
+\end_inset
+
+.
+
+\layout Section
+
The Z80 and gbz80 port
\layout Standard
T0IF = 0; /* Clear timer interrupt */
\newline
}
-\layout Standard
+\layout Subsection
Linking and assembling
-\newline
+\layout Standard
+
For assembling you can use either GPUTILS'
\begin_inset LatexCommand \index{gputils (pic tools)}
\end_inset
gpasm.exe or MPLAB's mpasmwin.exe.
+ GPUTILS is 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.
If you use MPLAB and an interrupt function then the linker script file
vectors section will need to be enlarged to link with mplink.
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-gplink -m -s $(PRJ).lkr -o $(PRJ).hex $(OBJS)
+gplink -m -s $(PRJ).lkr -o $(PRJ).hex $(OBJS) libsdcc.lib
\layout Standard
Here is a
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-mplink /v $(PRJ).lkr /m $(PRJ).map /o $(PRJ).hex $(OBJS)
-\layout Section
-
-The PIC16
-\begin_inset LatexCommand \index{PIC16}
+mplink /v $(PRJ).lkr /m $(PRJ).map /o $(PRJ).hex $(OBJS) libsdcc.lib
+\layout Standard
-\end_inset
+Please note that indentations within a
+\family typewriter
+ Makefile
+\family default
+ have to be done with a tabulator character.
+\layout Subsection
- port
+Command-line options
\layout Standard
-The PIC16
-\begin_inset LatexCommand \index{PIC16}
+Besides the switches common to all SDCC backends, the PIC14 port accepts
+ the following options (for an updated list see sdcc -
+\begin_inset ERT
+status Collapsed
-\end_inset
-
- port is the portion of SDCC that is responsible to produce code for the
- Microchip
-\begin_inset LatexCommand \index{Microchip}
+\layout Standard
+\backslash
+/
\end_inset
-(TM) microcontrollers with 16 bit core.
- Currently this family of microcontrollers contains the PIC18Fxxx and PIC18Fxxxx.
-\layout Subsection
-
-Global Options
-\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:
+-help):
\layout List
\labelwidthstring 00.00.0000
/
\end_inset
--stack-auto Auto variables that are function parameters, will be saved on
- stack by default.
-
-\emph on
-There is no need to specify this in the command line.
+-debug-extra emit debug info in assembly output
\layout List
\labelwidthstring 00.00.0000
/
\end_inset
--float-reent All floating point functions are reentrant by default.
-
-\emph on
-There is no need to specifiy this in the command line.
-\layout List
-\labelwidthstring 00.00.0000
+-no-pcode-opt disable (slightly faulty) optimization on pCode
+\layout Subsection
--
-\begin_inset ERT
-status Collapsed
+The library
+\layout Subsubsection
-\layout Standard
+error: missing definition for symbol
+\begin_inset Quotes sld
+\end_inset
-\backslash
-/
+__gptrget1
+\begin_inset Quotes srd
\end_inset
--callee-saves See -
-\begin_inset ERT
-status Collapsed
\layout Standard
-\backslash
-/
+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
+\family typewriter
+libsdcc.lib
+\family default
+ to the linker's arguments.
+ Make sure you also add an include path for the library (using the -I switch
+ to the linker)!
+\layout Subsubsection
+
+Processor mismatch in file
+\begin_inset Quotes sld
\end_inset
--all-callee-saves
-\layout List
-\labelwidthstring 00.00.0000
+XXX
+\begin_inset Quotes srd
+\end_inset
--
-\begin_inset ERT
-status Collapsed
+.
+\layout Standard
+This warning can usually be ignored due to the very good compatibility amongst
+ 14 bit PIC devices.
\layout Standard
-\backslash
-/
-\end_inset
+You might also consider recompiling the library for your specific device
+ by changing the ARCH=p16f877 (default target) entry in
+\family typewriter
+device/lib/pic/Makefile.in
+\family default
+ 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.
+\layout Subsection
--all-callee-saves All function arguments are passed on stack by default.
-
+Known bugs
+\layout Subsubsection
+
+initialized data
+\layout Standard
+
+Currently, data can only be initialized if it resides in the source file
+ together with
\emph on
-There is no need to specify this in the command line.
-\layout List
-\labelwidthstring 00.00.0000
+main()
+\emph default
+.
+ Data in other source files will silently
+\series bold
+not
+\series default
+ be initialized.
+\layout Section
--
-\begin_inset ERT
-status Collapsed
+The PIC16
+\begin_inset LatexCommand \index{PIC16}
+
+\end_inset
+ port
\layout Standard
-\backslash
-/
+The PIC16
+\begin_inset LatexCommand \index{PIC16}
+
\end_inset
--fommit-frame-pointer Frame pointer will be omitted when the function uses
- no local variables.
-\layout Subsection
+ port is the portion of SDCC that is responsible to produce code for the
+ Microchip
+\begin_inset LatexCommand \index{Microchip}
-PIC16 Port Specific Options
+\end_inset
+
+(TM) microcontrollers with 16 bit core.
+ Currently this family of microcontrollers contains the PIC18Fxxx and PIC18Fxxxx.
+ Currently supported devices are:
\layout Standard
+\align center
-The port specific options appear after the global options in the sdcc --help
- output.
-\layout Subsubsection
+\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
-General Options
\layout Standard
-General options enable certain port features and optimizations.
-\layout List
-\labelwidthstring 00.00.0000
-
--
-\begin_inset ERT
-status Collapsed
+18F242
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+18F248
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
--pgen-bank Instructs the port to insert BANKSEL directives before instructions
- that use the Bank Select Register (BSR).
-\layout List
-\labelwidthstring 00.00.0000
+\layout Standard
--
-\begin_inset ERT
-status Collapsed
+18F252
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+18F258
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
--pomit-config-words Instructs the port to omit the generation of the configurati
-on words.
-\layout List
-\labelwidthstring 00.00.0000
+\layout Standard
--
-\begin_inset ERT
-status Collapsed
+18F442
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+18F448
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
--pomit-ivt Instructs the port to omit the generation of the interrupt vectors
-\layout List
-\labelwidthstring 00.00.0000
+\layout Standard
--
-\begin_inset ERT
-status Collapsed
+18F452
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+18F458
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
--pleave-reset-vector Used in conjuction with the previous command, instructs
- the port NOT to omit the reset vector.
-\layout List
-\labelwidthstring 00.00.0000
+\layout Standard
--
-\begin_inset ERT
-status Collapsed
+18F1220
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+18F2220
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
--penable-stack Enables stack usage.
- All new development is done with stack enabled.
- This command line soon will be deprecated and stack will be enabled by
- default.
- For the time being it must be entered if one wants to have stack.
-\newline
-
-\series bold
-This option is deprecated.
- Stack is enabled by default in the port and there is no way to disable
- it.
- It is left here only for reference.
-\layout List
-\labelwidthstring 00.00.0000
+\layout Standard
--
-\begin_inset ERT
-status Collapsed
+18F2550
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+18F4331
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
--stack-model=[model] Used in conjuction with the command above.
- Defines the stack model to be used, valid stack models are :
-\begin_deeper
-\layout List
-\labelwidthstring 00.00.0000
+\layout Standard
+18F4455
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\emph on
-small
-\emph default
- Selects small stack model.
- 8 bit stack and frame pointers.
- Supports 256 bytes stack size.
-\layout List
-\labelwidthstring 00.00.0000
+\layout Standard
+18F6520
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\emph on
-large
-\emph default
- Selects large stack model.
- 16 bit stack and frame pointers.
- Supports 65536 bytes stack size.
-\end_deeper
-\layout List
-\labelwidthstring 00.00.0000
+\layout Standard
--
-\begin_inset ERT
-status Collapsed
+18F6620
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
-\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".
-\layout Subsubsection
-
-Debugging Options
-\layout Standard
-
-Debugging options enable extra debugging information in the output files.
-\layout List
-\labelwidthstring 00.00.0000
-
--
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
-
-\backslash
-/
-\end_inset
-
--debug-xtra Similar to --debug, but dumps more information.
-\layout List
-\labelwidthstring 00.00.0000
-
--
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
-
-\backslash
-/
-\end_inset
-
--debug-ralloc Force register allocator to dump <source>.d file with debugging
- information.
- <source> is the name of the file compiled.
-\layout List
-\labelwidthstring 00.00.0000
-
--
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
-
-\backslash
-/
+18F6680
\end_inset
-
--pcode-verbose Enable pcode debugging information in translation.
-\layout Subsection
-
-Preprocessor Macros
-\layout Standard
-
-PIC16 port defines the following preprocessor macros while translating a
- source.
-\layout Standard
-\align center
-
-\begin_inset Tabular
-<lyxtabular version="3" rows="2" columns="2">
-<features>
-<column alignment="center" valignment="top" leftline="true" width="0(null)">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0(null)">
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\begin_inset Text
\layout Standard
-Macro
+18F6720
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-Description
+18F8520
\end_inset
</cell>
</row>
\layout Standard
-pic18fxxxx
+18F8620
\end_inset
</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-MCU Identification.
-
-\emph on
-xxxx
-\emph default
- is the microcontrol identification number, i.e.
- 452, 6620, etc
+18F8680
\end_inset
</cell>
-</row>
-</lyxtabular>
-
-\end_inset
-
-
-\layout Subsection
-
-Directories
-\layout Standard
-
-PIC16 port uses the following directories for searching header files and
- libraries.
-\layout Standard
-\align center
-
-\begin_inset Tabular
-<lyxtabular version="3" rows="3" columns="4">
-<features>
-<column alignment="center" valignment="top" leftline="true" width="0(null)">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0(null)">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0(null)">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0(null)">
-<row topline="true" bottomline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-Directory
+18F8720
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-Description
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-Target
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-Command prefix
\end_inset
</cell>
</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
+</lyxtabular>
-PREFIX/sdcc/include/pic16
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-PIC16 specific headers
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+\layout Subsection
+Global Options
\layout Standard
-Compiler
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+PIC16 port supports the standard command line arguments as supposed, with
+ the exception of certain cases that will be mentioned in the following
+ list:
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
--I
+\backslash
+/
\end_inset
-</cell>
-</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+
+-callee-saves See -
+\begin_inset ERT
+status Collapsed
\layout Standard
-PREFIX/sdcc/lib/pic16
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-all-callee-saves
+\layout List
+\labelwidthstring 00.00.0000
-PIC16 specific libraries
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-Linker
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+
+-all-callee-saves All function arguments are passed on stack by default.
+
+\emph on
+There is no need to specify this in the command line.
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
--L
+\backslash
+/
\end_inset
-</cell>
-</row>
-</lyxtabular>
+
+-fommit-frame-pointer Frame pointer will be omitted when the function uses
+ no local variables.
+\layout Subsection
+
+Port Specific Options
+\begin_inset LatexCommand \index{Options PIC16}
\end_inset
-\layout Subsection
+\layout Standard
-Pragmas
+The port specific options appear after the global options in the sdcc --help
+ output.
+\layout Subsubsection
+
+General Options
\layout Standard
-PIC16 port currently supports the following pragmas:
+General options enable certain port features and optimizations.
\layout List
\labelwidthstring 00.00.0000
-stack pragma stack forces the code generator to initialize the stack & frame
- pointers at a specific address.
- This is an adhoc solution since gplink does not support yet stack.
- When the gplink issue is resolved the pragma will be deprecated
-\begin_inset Foot
-collapsed true
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-
-\emph on
-It is important to initialize the stack, otherwise strange things can happen.
- Stack is not initialized by default because there are some sources that
- do not require it.
- (like library sources)
+\backslash
+/
\end_inset
-.
-\newline
-If you omit setting the pragma the port emits a warning message before linking.
- If not initializing the stack is desired ignore the message.
-\layout LyX-Code
+-stack-model=[model] Used in conjuction with the command above.
+ Defines the stack model to be used, valid stack models are :
+\begin_deeper
+\layout List
+\labelwidthstring 00.00.0000
-Example:
-\layout LyX-Code
-\layout LyX-Code
+\emph on
+small
+\emph default
+ Selects small stack model.
+ 8 bit stack and frame pointers.
+ Supports 256 bytes stack size.
+\layout List
+\labelwidthstring 00.00.0000
-/* initializes stack at RAM address 0x5ff*/
-\layout LyX-Code
-#pragma stack 0x5ff
-\layout LyX-Code
+\emph on
+large
+\emph default
+ Selects large stack model.
+ 16 bit stack and frame pointers.
+ Supports 65536 bytes stack size.
+\end_deeper
+\layout List
+\labelwidthstring 00.00.0000
-\layout Subsection
+-
+\begin_inset ERT
+status Collapsed
-Header Files
\layout Standard
-There is one main header file that can be included to the source files using
- the pic16 port.
- That file is the
-\series bold
-pic18fregs.h
-\series default
-.
- This header file contains the definitions for the processor special registers,
- so it is necessery if the soruce accesses them.
- It can be included by adding the following line in the beginning of the
- file:
-\layout LyX-Code
-
-#include <pic18fregs.h>
-\layout Standard
+\backslash
+/
+\end_inset
-The specific microcontroller is selected within the pic18fregs.h automatically,
- so the same source can be used with a variety of devices.
-\layout Subsection
+-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".
+\layout List
+\labelwidthstring 00.00.0000
-Libraries
-\layout Standard
+-
+\begin_inset ERT
+status Collapsed
-The libraries that pic16 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
-\emph on
-xxxx
-\emph default
- is the microcontroller identification number.
- The specific library is selected automatically by the compiler at link
- stage according to the selected device.
\layout Standard
-Libraries are created with gplib which is part of the gputils package
-\begin_inset LatexCommand \url{http://gputils.sourceforge.net}
-
+\backslash
+/
\end_inset
-.
-\layout Subsection
-
-Memory Models
-\layout Standard
-
-The following memory models are supported by PIC16 port:
-\layout Itemize
+-ivt-loc <nnnn> positions the Interrupt Vector Table at location <nnnn>.
+ Useful for bootloaders.
+\layout List
+\labelwidthstring 00.00.0000
-small model
-\layout Itemize
+-
+\begin_inset ERT
+status Collapsed
-large model
\layout Standard
-Memory model affects the default size of pointers within the source.
- The sizes are shown in the next table:
-\layout Standard
-\align center
+\backslash
+/
+\end_inset
-\begin_inset Tabular
-<lyxtabular version="3" rows="3" columns="3">
-<features>
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0(null)">
-<column alignment="center" valignment="top" leftline="true" width="0(null)">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0(null)">
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+-asm= sets the full path and name of an external assembler to call.
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-Pointer sizes according to memory model
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-link= sets the full path and name of an external linker to call.
+\layout List
+\labelwidthstring 00.00.0000
-small model
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-large model
+\backslash
+/
\end_inset
-</cell>
-</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-mplab-comp MPLAB compatibility option.
+ Currently only suppresses special gpasm directives.
+\layout Subsubsection
-code pointers
-\end_inset
-</cell>
-<cell multicolumn="1" alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+Optimization Options
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-16-bits
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-optimize-goto Try to use (conditional) BRA instead of GOTO
+\layout List
+\labelwidthstring 00.00.0000
-24-bits
-\end_inset
-</cell>
-</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-data pointers
+\backslash
+/
\end_inset
-</cell>
-<cell multicolumn="1" alignment="center" valignment="top" topline="true" bottomline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-optimize-cmp Try to optimize some compares.
+\layout List
+\labelwidthstring 00.00.0000
-16-bits
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-16-bits
+\backslash
+/
\end_inset
-</cell>
-</row>
-</lyxtabular>
-\end_inset
+-optimize-df Analyze the dataflow of the generated code and improve it.
+\layout List
+\labelwidthstring 00.00.0000
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-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
-\series bold
-far
-\series default
- or
-\series bold
-near
-\series default
-.
- Far selects large memory model's pointers, while near selects small memory
- model's pointers.
-\layout Standard
+\backslash
+/
+\end_inset
-The standard device libraries (see 4.5.6) contain no reference to pointers,
- so they can be used with both memory models.
-\layout Subsection
+-obanksel=nn Set optimization level for inserting BANKSELs.
+\newline
-Stack
-\layout Standard
+\begin_deeper
+\layout List
+\labelwidthstring 00.00.0000
-The stack implementation for the PIC16 port uses two indirect registers,
- FSR1 and FSR2.
+0 no optimization
\layout List
\labelwidthstring 00.00.0000
-FSR1 is assigned as stack pointer
+1 checks previous used register and if it is the same then does not emit
+ BANKSEL, accounts only for labels.
\layout List
\labelwidthstring 00.00.0000
-FSR2 is assigned as frame pointer
-\layout Standard
+2 tries to check the location of (even different) symbols and removes BANKSELs
+ if they are in the same bank.
+
+\newline
-The following stack models are supported by PIC16 port
-\layout Itemize
+\emph on
+Important: There might be problems if the linker script has data sections
+ across bank borders!
+\end_deeper
+\layout Subsubsection
-small model
-\layout Itemize
+Linking Options
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
-large model
\layout Standard
+\backslash
+/
+\end_inset
-\noun on
-Small
-\noun default
- model means that only the FSRxL byte is used to access stack and frame,
- while
-\emph on
-\noun on
-large
-\emph default
-\noun default
- uses both FSRxL and FSRxH registers.
- The following table shows the stack/frame pointers sizes according to stack
- model and the maximum space they can address:
-\layout Standard
-\align center
+-nodefaultlibs do not link default libraries when linking
+\layout List
+\labelwidthstring 00.00.0000
-\begin_inset Tabular
-<lyxtabular version="3" rows="3" columns="3">
-<features>
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0(null)">
-<column alignment="center" valignment="top" leftline="true" width="0(null)">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0(null)">
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-Stack & Frame pointer sizes according to stack model
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-no-crt Don't link the default run-time modules
+\layout List
+\labelwidthstring 00.00.0000
-small
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-large
+\backslash
+/
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-use-crt= Use a custom run-time module instead of the defaults.
+\layout Subsubsection
-Stack pointer FSR1
+Debugging Options
+\layout Standard
+
+Debugging options enable extra debugging information in the output files.
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+
+-debug-xtra Similar to -
+\begin_inset ERT
+status Collapsed
\layout Standard
-8-bits
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+
+-debug
+\begin_inset LatexCommand \index{-\/-debug}
+
+\end_inset
+
+, but dumps more information.
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-16-bits
+\backslash
+/
\end_inset
-</cell>
-</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+
+-debug-ralloc Force register allocator to dump <source>.d file with debugging
+ information.
+ <source> is the name of the file compiled.
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-Frame pointer FSR2
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+
+-pcode-verbose Enable pcode debugging information in translation.
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-8-bits
+\backslash
+/
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+
+-denable-peeps Force the usage of peepholes.
+ Use with care.
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
\layout Standard
-16-bits
+\backslash
+/
\end_inset
-</cell>
-</row>
-</lyxtabular>
+-gstack Trace push/pops for stack pointer overflow
+\layout List
+\labelwidthstring 00.00.0000
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
\end_inset
+-call-tree dump call tree in .calltree file
+\layout Subsection
+
+Enviromental Variables
+\layout Standard
+
+There is a number of enviromental variables that can be used when running
+ SDCC to enable certain optimizations or force a specific program behaviour.
+ these variables are primarily for debugging purposes so they can be enabled/dis
+abled at will.
+\layout Standard
+
+Currently there is only two such variables available:
+\layout List
+\labelwidthstring 00.00.0000
+
+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).
+
+\layout List
+\labelwidthstring 00.00.0000
+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.
\layout Subsection
-Function return values
+Preprocessor Macros
\layout Standard
-Return values from functions are placed to the appropriate registers following
- a modified Microchip policy optimized for SDCC.
- The following table shows these registers:
+PIC16 port defines the following preprocessor macros while translating a
+ source.
\layout Standard
\align center
\begin_inset Tabular
<lyxtabular version="3" rows="6" columns="2">
<features>
-<column alignment="center" valignment="top" leftline="true" width="0(null)">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0(null)">
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
<row topline="true" bottomline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-size
+Macro
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-destination register
+Description
\end_inset
</cell>
</row>
\layout Standard
-8 bits
+SDCC_pic16
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-WREG
+Port identification
\end_inset
</cell>
</row>
\layout Standard
-16 bits
+_
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+_pic16
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-PRODL:WREG
+Port identification (same as above)
\end_inset
</cell>
</row>
\layout Standard
-24 bits
+pic18fxxxx
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-PRODH:PRODL:WREG
+MCU Identification.
+
+\emph on
+xxxx
+\emph default
+ is the microcontrol identification number, i.e.
+ 452, 6620, etc
\end_inset
</cell>
</row>
\layout Standard
-32 bits
+_
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+_18Fxxxx
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-FSR0L:PRODH:PRODL:WREG
+MCU Identification (same as above)
\end_inset
</cell>
</row>
\layout Standard
->32 bits
+STACK_MODEL_nnn
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-on stack, FSR0 points to the beginning
+nnn = SMALL or LARGE respectively according to the stack model used
\end_inset
</cell>
</row>
\end_inset
-\layout Subsection
+\layout Standard
-Interrupts
+In addition the following macros are defined when calling assembler:
\layout Standard
+\align center
-When entering an interrupt, currently the PIC16 port automatically saves
- the following registers:
-\layout Itemize
+\begin_inset Tabular
+<lyxtabular version="3" rows="4" columns="2">
+<features>
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-WREG
-\layout Itemize
+\layout Standard
-STATUS
-\layout Itemize
+Macro
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-BSR
-\layout Itemize
+\layout Standard
-PROD (PRODL and PRODH)
-\layout Itemize
+Description
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-FSR0 (FSR0L and FSR0H)
\layout Standard
-These registers are restored upon return from the interrupt routine
-\begin_inset Foot
-collapsed false
+__18Fxxxx
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-NOTE that when the _naked attribute is specified for an interrupt routine,
- then NO registers are stored or restored.
+MCU Identification.
+
+\emph on
+xxxx
+\emph default
+ is the microcontrol identification number, i.e.
+ 452, 6620, etc
\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-.
\layout Standard
-Currently interrupt enable flags are left unaffected when entering an interrupt
- routine.
- This may change in the future.
-\layout Chapter
+SDCC_MODEL_nnn
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-Debugging with SDCDB
-\begin_inset LatexCommand \label{cha:Debugging-with-SDCDB}
+\layout Standard
+nnn = SMALL or LARGE respectively according to the memory model used for
+ SDCC
\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\begin_inset LatexCommand \index{sdcdb (debugger)}
-
+STACK_MODEL_nnn
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-
\layout Standard
-SDCC is distributed with a source level debugger
-\begin_inset LatexCommand \index{Debugger}
+nnn = SMALL or LARGE respectively according to the stack model used
+\end_inset
+</cell>
+</row>
+</lyxtabular>
\end_inset
-.
- The debugger uses a command line interface, the command repertoire of the
- debugger has been kept as close to gdb
-\begin_inset LatexCommand \index{gdb}
+
+\layout Subsection
+
+Directories
+\layout Standard
+
+PIC16
+\begin_inset LatexCommand \index{PIC16}
\end_inset
- (the GNU debugger) as possible.
- The configuration and build process is part of the standard compiler installati
-on, which also builds and installs the debugger in the target directory
- specified during configuration.
- The debugger allows you debug BOTH at the C source and at the ASM source
- level.
- Sdcdb is available on Unix platforms only.
-\layout Section
+ port uses the following directories for searching header files and libraries.
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="3" columns="4">
+<features>
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<column alignment="center" valignment="top" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-Compiling for Debugging
\layout Standard
-The \SpecialChar \-
-\SpecialChar \-
-debug option must be specified for all files for which debug information
- is to be generated.
- The complier generates a .adb file for each of these files.
- The linker creates the .cdb
-\begin_inset LatexCommand \index{<file>.cdb}
+Directory
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+Description
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- file from the .adb
-\begin_inset LatexCommand \index{<file>.adb}
+\layout Standard
+Target
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
- files and the address information.
- This .cdb is used by the debugger.
-\layout Section
+\layout Standard
+
+Command prefix
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-How the Debugger Works
\layout Standard
-When the -
-\begin_inset ERT
-status Collapsed
+PREFIX/sdcc/include/pic16
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
\layout Standard
-\backslash
-/
+PIC16 specific headers
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
--debug option is specified the compiler generates extra symbol information
- some of which are put into the assembler source and some are put into the
- .adb file.
- Then the linker creates the .cdb file from the individual .adb files with
- the address information for the symbols.
- The debugger reads the symbolic information generated by the compiler &
- the address information generated by the linker.
- It uses the SIMULATOR (Daniel's S51) to execute the program, the program
- execution is controlled by the debugger.
- When a command is issued for the debugger, it translates it into appropriate
- commands for the simulator.
-\layout Section
+\layout Standard
+
+Compiler
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-Starting the Debugger
\layout Standard
-The debugger can be started using the following command line.
- (Assume the file you are debugging has the file name foo).
-\newline
+-I
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-\newline
+\layout Standard
-\family sans
-\series bold
-sdcdb foo
-\newline
+PREFIX/sdcc/lib/pic16
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\family default
-\series default
+\layout Standard
-\newline
-The debugger will look for the following files.
-\layout Itemize
+PIC16 specific libraries
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-foo.c - the source file.
-\layout Itemize
+\layout Standard
-foo.cdb - the debugger symbol information file.
-\layout Itemize
+Linker
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-foo.ihx - the Intel hex format
-\begin_inset LatexCommand \index{Intel hex format}
+\layout Standard
+-L
\end_inset
+</cell>
+</row>
+</lyxtabular>
- object file.
-\layout Section
+\end_inset
-Command Line Options.
-\layout Itemize
--
-\begin_inset ERT
-status Collapsed
+\layout Subsection
-\layout Standard
+Pragmas
+\begin_inset LatexCommand \label{sub:PIC16_Pragmas}
-\backslash
-/
\end_inset
--directory=<source file directory> this option can used to specify the directory
- search list.
- The debugger will look into the directory list specified for source, cdb
- & ihx files.
- The items in the directory list must be separated by ':', e.g.
- if the source files can be in the directories /home/src1 and /home/src2,
- the -
-\begin_inset ERT
-status Collapsed
\layout Standard
-\backslash
-/
-\end_inset
+PIC16 port currently supports the following pragmas:
+\layout List
+\labelwidthstring 00.00.0000
--directory option should be -
-\begin_inset ERT
-status Collapsed
+stack pragma stack 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
+ in the linker script or gplink is not instructed to create a stack section.
+\newline
+The stack pragma should be used only once in a project.
+ Multiple pragmas may result in indeterminate behaviour of the program.
+\begin_inset Foot
+collapsed false
\layout Standard
-\backslash
-/
+The old format (ie.
+ #pragma stack 0x5ff) is deprecated and will cause the stack pointer to
+ cross page boundaries (or even exceed the available data RAM) and crash
+ the program.
+ Make sure that stack does not cross page boundaries when using the SMALL
+ stack model.
\end_inset
--directory=/home/src1:/home/src2.
- Note there can be no spaces in the option.
-
-\layout Itemize
--cd <directory> - change to the <directory>.
-\layout Itemize
+\newline
+The format is as follows:
+\layout LyX-Code
--fullname - used by GUI front ends.
-\layout Itemize
+#pragma stack bottom_address [stack_size]
+\layout Standard
--cpu <cpu-type> - this argument is passed to the simulator please see the
- simulator docs for details.
-\layout Itemize
--X <Clock frequency > this options is passed to the simulator please see
- the simulator docs for details.
-\layout Itemize
+\emph on
+bottom_address
+\emph default
+ is the lower bound of the stack section.
+ The stack pointer initially will point at address (bottom_address+stack_size-1).
+\layout LyX-Code
--s <serial port file> passed to simulator see the simulator docs for details.
-\layout Itemize
+Example:
+\layout LyX-Code
--S <serial in,out> passed to simulator see the simulator docs for details.
-\layout Itemize
+\layout LyX-Code
--k <port number> passed to simulator see the simulator docs for details.
-\layout Section
+/* initializes stack of 100 bytes at RAM address 0x200 */
+\layout LyX-Code
-Debugger Commands.
+#pragma stack 0x200 100
\layout Standard
-As mentioned earlier the command interface for the debugger has been deliberatel
-y kept as close the GNU debugger gdb, as possible.
- This will help the integration with existing graphical user interfaces
- (like ddd, xxgdb or xemacs) existing for the GNU debugger.
- If you use a graphical user interface for the debugger you can skip the
- next sections.
-\layout Subsubsection*
+If the stack_size field is omitted then a stack is created with the default
+ size of 64.
+ This size might be enough for most programs, but its not enough for operations
+ with deep function nesting or excessive stack usage.
+\layout List
+\labelwidthstring 00.00.0000
-break [line | file:line | function | file:function]
-\layout Standard
+wparam
+\emph on
+This pragma is deprecated.
+ Its use will cause a warning message to be issued.
+\emph default
-Set breakpoint at specified line or function:
\newline
-\newline
+\layout List
+\labelwidthstring 00.00.0000
-\family sans
-\series bold
-sdcdb>break 100
-\newline
-sdcdb>break foo.c:100
-\newline
-sdcdb>break funcfoo
-\newline
-sdcdb>break foo.c:funcfoo
-\layout Subsubsection*
+code place a function symbol at static FLASH address
+\layout LyX-Code
-clear [line | file:line | function | file:function ]
-\layout Standard
+Example:
+\layout LyX-Code
-Clear breakpoint at specified line or function:
-\newline
+\layout LyX-Code
-\newline
+/* place function test_func at 0x4000 */
+\layout LyX-Code
-\family sans
-\series bold
-sdcdb>clear 100
-\newline
-sdcdb>clear foo.c:100
-\newline
-sdcdb>clear funcfoo
+#pragma code test_func 0x4000
+\layout LyX-Code
+
+\layout List
+\labelwidthstring 00.00.0000
+
+library instructs the linker to use a library module.
\newline
-sdcdb>clear foo.c:funcfoo
-\layout Subsubsection*
+Usage:
+\layout LyX-Code
-continue
+#pragma library module_name
\layout Standard
-Continue program being debugged, after breakpoint.
-\layout Subsubsection*
-finish
+\emph on
+module_name
+\emph default
+ can be any library or object file (including its path).
+ Note that there are four reserved keywords which have special meaning.
+ These are:
\layout Standard
+\align center
-Execute till the end of the current function.
-\layout Subsubsection*
+\begin_inset Tabular
+<lyxtabular version="3" rows="6" columns="3">
+<features>
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="block" valignment="top" leftline="true" width="20page%">
+<column alignment="left" valignment="top" leftline="true" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-delete [n]
\layout Standard
-Delete breakpoint number 'n'.
- If used without any option clear ALL user defined break points.
-\layout Subsubsection*
+Keyword
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-info [break | stack | frame | registers ]
-\layout Itemize
+\layout Standard
-info break - list all breakpoints
-\layout Itemize
+Description
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-info stack - show the function call stack.
-\layout Itemize
+\layout Standard
-info frame - show information about the current execution frame.
-\layout Itemize
+Module to link
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-info registers - show content of all registers.
-\layout Subsubsection*
+\layout Standard
+
+
+\series bold
+ignore
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-step
\layout Standard
-Step program until it reaches a different source line.
- Note: pressing <return> repeats the last command.
-\layout Subsubsection*
+ignore all library pragmas
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-next
\layout Standard
-Step program, proceeding through subroutine calls.
-\layout Subsubsection*
-run
+\emph on
+(none)
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
\layout Standard
-Start debugged program.
-\layout Subsubsection*
-ptype variable
+\series bold
+c
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
\layout Standard
-Print type information of the variable.
-\layout Subsubsection*
+link the C library
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-print variable
\layout Standard
-print value of variable.
-\layout Subsubsection*
-file filename
+\emph on
+libc18f
+\emph default
+.lib
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
\layout Standard
-load the given file name.
- Note this is an alternate method of loading file for debugging.
-\layout Subsubsection*
-frame
+\series bold
+math
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
\layout Standard
-print information about current frame.
-\layout Subsubsection*
+link the Math libarary
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-set srcmode
\layout Standard
-Toggle between C source & assembly source.
-\layout Subsubsection*
-! simulator command
+\emph on
+libm18f
+\emph default
+.lib
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
\layout Standard
-Send the string following '!' to the simulator, the simulator response is
- displayed.
- Note the debugger does not interpret the command being sent to the simulator,
- so if a command like 'go' is sent the debugger can loose its execution
- context and may display incorrect values.
-\layout Subsubsection*
-quit
+\series bold
+io
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
\layout Standard
-"Watch me now.
- Iam going Down.
- My name is Bobby Brown"
-\layout Section
+link the I/O library
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-Interfacing with XEmacs
-\begin_inset LatexCommand \index{XEmacs}
+\layout Standard
+
+\emph on
+libio18f*
+\emph default
+.lib
\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+\layout Standard
-\begin_inset LatexCommand \index{Emacs}
+\series bold
+debug
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
-.
\layout Standard
-Two files (in emacs lisp) are provided for the interfacing with XEmacs,
- sdcdb.el and sdcdbsrc.el.
- These two files can be found in the $(prefix)/bin directory after the installat
-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):
-\newline
+link the debug library
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-\newline
+\layout Standard
-\family typewriter
-(load-file sdcdbsrc.el)
-\family default
-\newline
+\emph on
+libdebug
+\emph default
+.lib
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
-\newline
-.xemacs is a lisp file so the () around the command is REQUIRED.
- 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:
-\newline
\newline
+* is the device number, i.e.
+ 452 for PIC18F452 MCU.
+\layout Standard
-\family sans
-\series bold
-ESC-x sdcdbsrc
-\family default
-\series default
+This feature allows for linking with specific libraries withoug having to
+ explicit name them in the command line.
+ Note that the
+\noun on
+ignore
+\noun default
+ keyword will reject all modules specified by the library pragma.
+\layout List
+\labelwidthstring 00.00.0000
-\newline
+udata pragma udata instructs the compiler to emit code so that linker will
+ place a variable at a specific memory bank
+\layout LyX-Code
-\newline
-You will prompted to enter the file name to be debugged.
-
-\newline
+Example:
+\layout LyX-Code
-\newline
-The command line options that are passed to the simulator directly are bound
- to default values in the file sdcdbsrc.el.
- The variables are listed below, these values maybe changed as required.
-\layout Itemize
+\layout LyX-Code
-sdcdbsrc-cpu-type '51
-\layout Itemize
+/* places variable foo at bank2 */
+\layout LyX-Code
-sdcdbsrc-frequency '11059200
-\layout Itemize
+#pragma udata bank2 foo
+\layout LyX-Code
-sdcdbsrc-serial nil
+char foo;
\layout Standard
-The following is a list of key mapping for the debugger interface.
-\layout Standard
+In order for this pragma to work extra SECTION directives should be added
+ in the .lkr script.
+ In the following example a sample .lkr file is shown:
+\layout LyX-Code
-\SpecialChar ~
+\layout LyX-Code
-\family typewriter
+// Sample linker script for the PIC18F452 processor
+\layout LyX-Code
-\newline
-;; Current Listing ::
-\newline
-;;key\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-binding\SpecialChar ~
+LIBPATH .
+\layout LyX-Code
+
+CODEPAGE NAME=vectors START=0x0 END=0x29 PROTECTED
+\layout LyX-Code
+
+CODEPAGE NAME=page START=0x2A END=0x7FFF
+\layout LyX-Code
+
+CODEPAGE NAME=idlocs START=0x200000 END=0x200007 PROTECTED
+\layout LyX-Code
+
+CODEPAGE NAME=config START=0x300000 END=0x30000D PROTECTED
+\layout LyX-Code
+
+CODEPAGE NAME=devid START=0x3FFFFE END=0x3FFFFF PROTECTED
+\layout LyX-Code
+
+CODEPAGE NAME=eedata START=0xF00000 END=0xF000FF PROTECTED
+\layout LyX-Code
+
+ACCESSBANK NAME=accessram START=0x0 END=0x7F
+\layout LyX-Code
+
+\layout LyX-Code
+
+DATABANK NAME=gpr0 START=0x80 END=0xFF
+\layout LyX-Code
+
+DATABANK NAME=gpr1 START=0x100 END=0x1FF
+\layout LyX-Code
+
+DATABANK NAME=gpr2 START=0x200 END=0x2FF
+\layout LyX-Code
+
+DATABANK NAME=gpr3 START=0x300 END=0x3FF
+\layout LyX-Code
+
+DATABANK NAME=gpr4 START=0x400 END=0x4FF
+\layout LyX-Code
+
+DATABANK NAME=gpr5 START=0x500 END=0x5FF
+\layout LyX-Code
+
+ACCESSBANK NAME=accesssfr START=0xF80 END=0xFFF PROTECTED
+\layout LyX-Code
+
+\layout LyX-Code
+
+SECTION NAME=CONFIG ROM=config
+\layout LyX-Code
+
+\layout LyX-Code
+
+SECTION NAME=bank0 RAM=gpr0 # these SECTION directives
+\layout LyX-Code
+
+SECTION NAME=bank1 RAM=gpr1 # should be added to link
+\layout LyX-Code
+
+SECTION NAME=bank2 RAM=gpr2 # section name 'bank?' with
+\layout LyX-Code
+
+SECTION NAME=bank3 RAM=gpr3 # a specific DATABANK name
+\layout LyX-Code
+
+SECTION NAME=bank4 RAM=gpr4
+\layout LyX-Code
+
+SECTION NAME=bank5 RAM=gpr5
+\layout Standard
+
+The linker will recognise the section name set in the pragma statement and
+ will position the variable at the memory bank set with the RAM field at
+ the SECTION line in the linker script file.
+\layout Subsection
+
+Header Files
+\begin_inset LatexCommand \label{sub:PIC16_Header-Files}
+
+\end_inset
+
+
+\layout Standard
+
+There is one main header file that can be included to the source files using
+ the pic16 port.
+ That file is the
+\series bold
+pic18fregs.h
+\series default
+.
+ This header file contains the definitions for the processor special registers,
+ so it is necessary if the source accesses them.
+ It can be included by adding the following line in the beginning of the
+ file:
+\layout LyX-Code
+
+#include <pic18fregs.h>
+\layout Standard
+
+The specific microcontroller is selected within the pic18fregs.h automatically,
+ so the same source can be used with a variety of devices.
+\layout Subsection
+
+Libraries
+\layout Standard
+
+The libraries that PIC16
+\begin_inset LatexCommand \index{PIC16}
+
+\end_inset
+
+ 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
+\emph on
+xxxx
+\emph default
+ is the microcontroller identification number.
+ The specific library is selected automatically by the compiler at link
+ stage according to the selected device.
+\layout Standard
+
+Libraries are created with gplib which is part of the gputils package
+\begin_inset LatexCommand \url{http://sourceforge.net/projects/gputils}
+
+\end_inset
+
+.
+\layout Subsubsection*
+
+Building the libraries
+\layout Standard
+
+Before using SDCC/pic16 there are some libraries that need to be compiled.
+ This process is not done automatically by SDCC since not all users use
+ SDCC for pic16 projects.
+ So each user should compile the libraries separately.
+\layout Standard
+
+The steps to compile the pic16 libraries under Linux are:
+\layout LyX-Code
+
+cd device/lib/pic16
+\layout LyX-Code
+
+./configure
+\layout LyX-Code
+
+make
+\layout LyX-Code
+
+cd ..
+\layout LyX-Code
+
+make model-pic16
+\layout LyX-Code
+
+su -c 'make install' # install the libraries, you need the root password
+\layout Standard
+
+If you need to install the headers too, do:
+\layout LyX-Code
+
+cd device/include
+\layout LyX-Code
+
+su -c 'make install' # install the headers, you need the root password
+\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
+\emph on
+every
+\emph default
+ supported device.
+ This way building will take quite a lot of time.
+ Users are advised to edit the
+\series bold
+device/lib/pic16/pics.build
+\series default
+ file and then execute:
+\layout LyX-Code
+
+make lib-io
+\layout Subsection
+
+Memory Models
+\layout Standard
+
+The following memory models are supported by the PIC16 port:
+\layout Itemize
+
+small model
+\layout Itemize
+
+large model
+\layout Standard
+
+Memory model affects the default size of pointers within the source.
+ The sizes are shown in the next table:
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="3" columns="3">
+<features>
+<column alignment="center" valignment="top" leftline="true" rightline="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" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Pointer sizes according to memory model
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+small model
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+large model
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+code pointers
+\end_inset
+</cell>
+<cell multicolumn="1" alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+16-bits
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+24-bits
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+data pointers
+\end_inset
+</cell>
+<cell multicolumn="1" alignment="center" valignment="top" topline="true" bottomline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+16-bits
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+16-bits
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\layout Standard
+
+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
+\series bold
+far
+\series default
+ or
+\series bold
+near
+\series default
+.
+ Far selects large memory model's pointers, while near selects small memory
+ model's pointers.
+\layout Standard
+
+The standard device libraries (see
+\begin_inset LatexCommand \ref{sub:PIC16_Header-Files}
+
+\end_inset
+
+) contain no reference to pointers, so they can be used with both memory
+ models.
+\layout Subsection
+
+Stack
+\layout Standard
+
+The stack implementation for the PIC16 port uses two indirect registers,
+ FSR1 and FSR2.
+\layout List
+\labelwidthstring 00.00.0000
+
+FSR1 is assigned as stack pointer
+\layout List
+\labelwidthstring 00.00.0000
+
+FSR2 is assigned as frame pointer
+\layout Standard
+
+The following stack models are supported by the PIC16 port
+\layout Itemize
+
+
+\noun on
+small
+\noun default
+ model
+\layout Itemize
+
+
+\noun on
+large
+\noun default
+ model
+\layout Standard
+
+
+\noun on
+Small
+\noun default
+ model means that only the FSRxL byte is used to access stack and frame,
+ while
+\emph on
+\noun on
+large
+\emph default
+\noun default
+ uses both FSRxL and FSRxH registers.
+ The following table shows the stack/frame pointers sizes according to stack
+ model and the maximum space they can address:
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="3" columns="3">
+<features>
+<column alignment="center" valignment="top" leftline="true" rightline="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" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Stack & Frame pointer sizes according to stack model
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+small
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+large
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Stack pointer FSR1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+8-bits
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+16-bits
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Frame pointer FSR2
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+8-bits
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+16-bits
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\layout Standard
+
+
+\noun on
+Large
+\noun default
+stack model is currently not working properly throughout the code generator.
+ So its use is not advised.
+ Also there are some other points that need special care:
+\newline
+
+\layout Enumerate
+
+Do not create stack sections with size more than one physical bank (that
+ is 256 bytes)
+\layout Enumerate
+
+Stack sections should no cross physical bank limits (i.e.
+ #pragma stack 0x50 0x100)
+\layout Standard
+
+These limitations are caused by the fact that only FSRxL is modified when
+ using SMALL stack model, so no more than 256 bytes of stack can be used.
+ This problem will disappear after LARGE model is fully implemented.
+\layout Subsection
+
+Functions
+\layout Standard
+
+In addition to the standard SDCC function keywords, PIC16 port makes available
+ two more:
+\layout List
+\labelwidthstring 00.00.0000
+
+wparam Use the WREG to pass one byte of the first function argument.
+ This improves speed but you may not use this for functions with arguments
+ that are called via function pointers, otherwise the first byte of the
+ first parameter will get lost.
+ Usage:
+\layout LyX-Code
+
+void func_wparam(int a) wparam
+\layout LyX-Code
+
+{
+\layout LyX-Code
+
+ /* WREG hold the lower part of a */
+\layout LyX-Code
+
+ /* the high part of a is stored in FSR2+2 (or +3 for large stack model)
+ */
+\layout LyX-Code
+
+...
+\layout LyX-Code
+
+}
+\layout Standard
+
+This keyword replaces the deprecated wparam pragma.
+\layout List
+\labelwidthstring 00.00.0000
+
+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
+\emph on
+shadowregs
+\emph default
+ before the
+\emph on
+interrupt
+\emph default
+ keyword in the function's header.
+\layout LyX-Code
+
+void isr_shadow(void) shadowregs interrupt 1
+\layout LyX-Code
+
+{
+\layout LyX-Code
+
+...
+\layout LyX-Code
+
+}
+\layout Standard
+
+
+\emph on
+shadowregs
+\emph default
+ instructs the code generator not to store/restore WREG, STATUS, BSR when
+ entering/exiting the ISR.
+\layout Subsection
+
+Function return values
+\layout Standard
+
+Return values from functions are placed to the appropriate registers following
+ a modified Microchip policy optimized for SDCC.
+ The following table shows these registers:
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="6" columns="2">
+<features>
+<column alignment="center" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+size
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+destination register
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+8 bits
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+WREG
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+16 bits
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+PRODL:WREG
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+24 bits
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+PRODH:PRODL:WREG
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+32 bits
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+FSR0L:PRODH:PRODL:WREG
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+>32 bits
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+on stack, FSR0 points to the beginning
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\layout Subsection
+
+Interrupts
+\layout Standard
+
+An interrupt servive routine (ISR) is declared using the
+\emph on
+interrupt
+\emph default
+ keyword.
+\layout LyX-Code
+
+void isr(void) interrupt
+\emph on
+n
+\layout LyX-Code
+
+{
+\layout LyX-Code
+
+...
+\layout LyX-Code
+
+}
+\layout Standard
+
+
+\emph on
+n
+\emph default
+ is the interrupt number, which for PIC18F devices can be:
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="4" columns="3">
+<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" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\emph on
+n
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Interrupt Vector
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Interrupt Vector Address
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+RESET vector
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0x000000
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+HIGH priority interrupts
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0x000008
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+2
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+LOW priority interrupts
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0x000018
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\layout Standard
+
+When generating assembly code for ISR the code generator places a
+\noun on
+goto
+\noun default
+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
+\emph on
+interrupt entry point
+\emph default
+ function.
+ 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
+\series bold
+not
+\series default
+ generated.
+ The whole interrupt functions is therefore placed at the Interrupt Vector
+ 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
+ behaviour if that interrupt is raised.
+\begin_inset Foot
+collapsed false
+
+\layout Standard
+
+This is not a problem when
+\layout Enumerate
+
+this is a HIGH interrupt ISR and LOW interrupts are
+\emph on
+disabled
+\emph default
+ or not used.
+\layout Enumerate
+
+when the ISR is small enough not to reach the next interrupt´s vector address.
+\end_inset
+
+
+\layout Standard
+
+
+\emph on
+n
+\emph default
+ is possible to be omitted.
+ This way a function is generated similar to an ISR, but it is not assigned
+ to any interrupt.
+\layout Standard
+
+When entering an interrupt, currently the PIC16
+\begin_inset LatexCommand \index{PIC16}
+
+\end_inset
+
+ port automatically saves the following registers:
+\layout Itemize
+
+WREG
+\layout Itemize
+
+STATUS
+\layout Itemize
+
+BSR
+\layout Itemize
+
+PROD (PRODL and PRODH)
+\layout Itemize
+
+FSR0 (FSR0L and FSR0H)
+\layout Standard
+
+These registers are restored upon return from the interrupt routine.
+\begin_inset Foot
+collapsed false
+
+\layout Standard
+
+NOTE that when the _naked attribute is specified for an interrupt routine,
+ then NO registers are stored or restored.
+\end_inset
+
+
+\layout Subsection
+
+Generic Pointers
+\layout Standard
+
+Generic pointers are implemented in PIC16 port as 3-byte (24-bit) types.
+ There are 3 types of generic pointers currently implemented data, code
+ and eeprom pointers.
+ They are differentiated by the value of the 7th and 6th bits of the upper
+ byte:
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="5" columns="5">
+<features>
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<column alignment="center" valignment="top" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<column alignment="center" valignment="top" width="0">
+<column alignment="left" valignment="top" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+pointer type
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+7th bit
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+6th bit
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+rest of the pointer
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+descrption
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+data
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family typewriter
+\shape slanted
+\emph on
+uuuuuu uuuuxxxx xxxxxxxx
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+a 12-bit data pointer in data RAM memory
+\end_inset
+</cell>
+</row>
+<row bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+code
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family typewriter
+\shape slanted
+\emph on
+uxxxxx xxxxxxxx xxxxxxxx
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+a 21-bit code pointer in FLASH memory
+\end_inset
+</cell>
+</row>
+<row bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+eeprom
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family typewriter
+\shape slanted
+\emph on
+uuuuuu uuuuuuxx xxxxxxxx
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+a 10-bit eeprom pointer in EEPROM memory
+\end_inset
+</cell>
+</row>
+<row bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+(unimplemented)
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family typewriter
+\shape slanted
+\emph on
+xxxxxx xxxxxxxx xxxxxxxx
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+unimplemented pointer type
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\layout Standard
+
+Generic pointer are read and written with a set of library functions which
+ read/write 1, 2, 3, 4 bytes.
+\layout Subsection
+
+PIC16 C Libraries
+\layout Subsubsection
+
+Standard I/O Streams
+\layout Standard
+
+In the
+\emph on
+stdio.h
+\emph default
+ the type FILE is defined as:
+\layout LyX-Code
+
+typedef char * FILE;
+\layout Standard
+
+This type is the stream type implemented I/O in the PIC18F devices.
+ Also the standard input and output streams are declared in stdio.h:
+\layout LyX-Code
+
+extern FILE * stdin;
+\layout LyX-Code
+
+extern FILE * stdout;
+\layout Standard
+
+The FILE type is actually a generic pointer which defines one more type
+ of generic pointers, the
+\emph on
+stream
+\emph default
+pointer.
+ This new type has the format:
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="2" columns="7">
+<features>
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<column alignment="center" valignment="top" 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">
+<column alignment="center" valignment="top" width="0">
+<column alignment="left" valignment="top" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+pointer type
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+<7:6>
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+<5>
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+<4>
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+<3:0>
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+rest of the pointer
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+descrption
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+stream
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+00
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+0
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+nnnn
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family typewriter
+\shape slanted
+\emph on
+uuuuuuuu uuuuuuuu
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+upper byte high nubble is 0x2n, the rest are zeroes
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\layout Standard
+
+Currently implemented there are 3 types of streams defined:
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="4" columns="4">
+<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" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+stream type
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+value
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+module
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+description
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+STREAM_USART
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family typewriter
+0x200000UL
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+USART
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Writes/Reads characters via the USART peripheral
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+STREAM_MSSP
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family typewriter
+0x210000UL
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+MSSP
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Writes/Reads characters via the MSSP peripheral
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+STREAM_USER
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family typewriter
+0x2f0000UL
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+(none)
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Writes/Reads characters via used defined functions
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\layout Standard
+
+The stream identifiers are declared as macros in the stdio.h header.
+\layout Standard
+
+In the libc library there exist the functions that are used to write to
+ each of the above streams.
+ These are
+\layout List
+\labelwidthstring 00.00.0000
+
+_
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+_stream_usart_putchar writes a character at the USART stream
+\layout List
+\labelwidthstring 00.00.0000
+
+_
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+_stream_mssp_putchar writes a character at the MSSP stream
+\layout List
+\labelwidthstring 00.00.0000
+
+putchar dummy function.
+ This writes a character to a user specified manner.
+\layout Standard
+
+In order to increase performance
+\emph on
+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
+ is the name of the variable that holds the character to print.
+ An example follows:
+\layout LyX-Code
+
+#include <pic18fregs.h>
+\newline
+#include <stdio.h>
+\newline
+
+\newline
+PUTCHAR( c )
+\layout LyX-Code
+
+{
+\layout LyX-Code
+
+ PORTA = c; /* dump character c to PORTA */
+\layout LyX-Code
+
+}
+\newline
+
+\newline
+void main(void)
+\layout LyX-Code
+
+{
+\layout LyX-Code
+
+ stdout = STREAM_USER; /* this is not necessery, since stdout points
+\layout LyX-Code
+
+ * by default to STREAM_USER */
+\layout LyX-Code
+
+ printf (¨This is a printf test
+\backslash
+n¨);
+\layout LyX-Code
+
+}
+\layout LyX-Code
+
+\layout Subsubsection
+
+Printing functions
+\layout Standard
+
+PIC16 contains an implementation of the printf-family of functions.
+ There exist the following functions:
+\layout LyX-Code
+
+extern unsigned int sprintf(char *buf, char *fmt, ...);
+\layout LyX-Code
+
+extern unsigned int vsprintf(char *buf, char *fmt, va_list ap);
+\layout LyX-Code
+
+\layout LyX-Code
+
+extern unsigned int printf(char *fmt, ...);
+\layout LyX-Code
+
+extern unsigned int vprintf(char *fmt, va_lista ap);
+\layout LyX-Code
+
+\layout LyX-Code
+
+extern unsigned int fprintf(FILE *fp, char *fmt, ...);
+\layout LyX-Code
+
+extern unsigned int vfprintf(FILE *fp, char *fmt, va_list ap);
+\layout Standard
+
+For sprintf and vsprintf
+\emph on
+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
+\emph on
+fp
+\emph default
+ should be a stream pointer (i.e.
+ stdout, STREAM_MSSP, etc...).
+\layout Subsubsection
+
+Signals
+\layout Standard
+
+The PIC18F family of microcontrollers supports a number of interrupt sources.
+ A list of these interrupts is shown in the following table:
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="11" columns="4">
+<features>
+<column alignment="left" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<column alignment="left" valignment="top" leftline="true" width="0">
+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+signal name
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+description
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+signal name
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+descritpion
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_RB
+\end_inset
+</cell>
+<cell multicolumn="1" alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+PORTB change interrupt
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_EE
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+EEPROM/FLASH write complete interrupt
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_INT0
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+INT0 external interrupt
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_BCOL
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Bus collision interrupt
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_INT1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+INT1 external interrupt
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_LVD
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Low voltage detect interrupt
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_INT2
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+INT2 external interrupt
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_PSP
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Parallel slave port interrupt
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_CCP1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+CCP1 module interrupt
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_AD
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+AD convertion complete interrupt
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_CCP2
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+CCP2 module interrupt
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_RC
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+USART receive interrupt
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_TMR0
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+TMR0 overflow interrupt
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_TX
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+USART transmit interrupt
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_TMR1
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+TMR1 overflow interrupt
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_MSSP
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SSP receive/transmit interrupt
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_TMR2
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+TMR2 matches PR2 interrupt
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+SIG_TMR3
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+TMR3 overflow interrupt
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+\end_inset
+</cell>
+</row>
+</lyxtabular>
+
+\end_inset
+
+
+\layout Standard
+
+The prototypes for these names are defined in the header file
+\emph on
+signal.h
+\emph default
+ .
+\layout Standard
+
+In order to simplify signal handling, a number of macros is provided:
+\layout List
+\labelwidthstring 00.00.0000
+
+DEF_INTHIGH(name) begin the definition of the interrupt dispatch table for
+ high priority interrupts.
+
+\emph on
+name
+\emph default
+ is the function name to use.
+\layout List
+\labelwidthstring 00.00.0000
+
+DEF_INTLOW(name) begin the definition of the interrupt dispatch table fo
+ low priority interrupt.
+
+\emph on
+name
+\emph default
+ is the function name to use.
+\layout List
+\labelwidthstring 00.00.0000
+
+DEF_HANDLER(sig,handler) define a handler for signal
+\emph on
+sig.
+\layout List
+\labelwidthstring 00.00.0000
+
+END_DEF end the declaration of the dispatch table.
+\layout Standard
+
+Additionally there are two more macros to simplify the declaration of the
+ signal handler:
+\layout List
+\labelwidthstring 00.00.0000
+
+
+\series medium
+SIGHANDLER(handler)
+\series default
+this declares the function prototype for the
+\emph on
+handler
+\emph default
+ function.
+\layout List
+\labelwidthstring 00.00.0000
+
+SIGHANDLERNAKED(handler) same as SIGHANDLER() but declares a naked function.
+\layout Standard
+
+An example of using the macros above is shown below:
+\layout LyX-Code
+
+#include <pic18fregs.h>
+\layout LyX-Code
+
+#include <signal.h>
+\newline
+
+\newline
+DEF_INTHIGH(high_int)
+\layout LyX-Code
+
+DEF_HANDLER(SIG_TMR0, _tmr0_handler)
+\layout LyX-Code
+
+DEF_HANDLER(SIG_BCOL, _bcol_handler)
+\layout LyX-Code
+
+END_DEF
+\newline
+
+\newline
+SIGHANDLER(_tmr0_handler)
+\layout LyX-Code
+
+{
+\layout LyX-Code
+
+ /* action to be taken when timer 0 overflows */
+\layout LyX-Code
+
+}
+\newline
+
+\newline
+SIGHANDLERNAKED(_bcol_handler)
+\layout LyX-Code
+
+{
+\layout LyX-Code
+
+ _asm
+\layout LyX-Code
+
+ /* action to be taken when bus collision occurs */
+\layout LyX-Code
+
+ retfie
+\layout LyX-Code
+
+ _endasm;
+\layout LyX-Code
+
+}
+\layout Standard
+
+
+\series bold
+NOTES:
+\series default
+ Special care should be taken when using the above scheme:
+\layout Itemize
+
+do not place a colon (;) at the end of the DEF_* and END_DEF macros.
+\layout Itemize
+
+when declaring SIGHANDLERNAKED handler never forget to use
+\emph on
+retfie
+\emph default
+ for proper returning.
+\layout Subsection
+
+PIC16 Port -- Tips
+\layout Standard
+
+Here you can find some general tips for compiling programs with SDCC/pic16.
+\layout Subsubsection
+
+Stack size
+\layout Standard
+
+The default stack size (that is 64 bytes) probably is enough for many programs.
+ One must take care that when there are many levels of function nesting,
+ or there is excessive usage of stack, its size should be extended.
+ An example of such a case is the printf/sprintf family of functions.
+ If you encounter problems like not being able to print integers, then you
+ need to set the stack size around the maximum (256 for small stack model).
+ The following diagram shows what happens when calling printf to print an
+ integer:
+\layout LyX-Code
+
+printf () --> ltoa () --> ultoa () --> divschar ()
+\layout Standard
+
+It is should be understood that stack is easily consumed when calling complicate
+d functions.
+ Using command line arguments like -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-fommit-frame-pointer might reduce stack usage by not creating unnecessery
+ stack frames.
+ Other ways to reduce stack usage may exist.
+\layout Chapter
+
+Debugging with SDCDB
+\begin_inset LatexCommand \label{cha:Debugging-with-SDCDB}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{sdcdb (debugger)}
+
+\end_inset
+
+
+\layout Standard
+
+SDCC is distributed with a source level debugger
+\begin_inset LatexCommand \index{Debugger}
+
+\end_inset
+
+.
+ The debugger uses a command line interface, the command repertoire of the
+ debugger has been kept as close to gdb
+\begin_inset LatexCommand \index{gdb}
+
+\end_inset
+
+ (the GNU debugger) as possible.
+ The configuration and build process is part of the standard compiler installati
+on, which also builds and installs the debugger in the target directory
+ specified during configuration.
+ The debugger allows you debug BOTH at the C source and at the ASM source
+ level.
+ Sdcdb is currently not available on Win32 platforms.
+\layout Section
+
+Compiling for Debugging
+\layout Standard
+
+The -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-debug
+\begin_inset LatexCommand \index{-\/-debug}
+
+\end_inset
+
+ option must be specified for all files for which debug information is to
+ be generated.
+ The complier generates a .adb file for each of these files.
+ The linker creates the .cdb
+\begin_inset LatexCommand \index{<file>.cdb}
+
+\end_inset
+
+ file from the .adb
+\begin_inset LatexCommand \index{<file>.adb}
+
+\end_inset
+
+ files and the address information.
+ This .cdb is used by the debugger.
+\layout Section
+
+How the Debugger Works
+\layout Standard
+
+When the -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-debug option is specified the compiler generates extra symbol information
+ some of which are put into the assembler source and some are put into the
+ .adb file.
+ Then the linker creates the .cdb file from the individual .adb files with
+ the address information for the symbols.
+ The debugger reads the symbolic information generated by the compiler &
+ the address information generated by the linker.
+ It uses the SIMULATOR (Daniel's S51) to execute the program, the program
+ execution is controlled by the debugger.
+ When a command is issued for the debugger, it translates it into appropriate
+ commands for the simulator.
+\layout Section
+
+Starting the Debugger
+\layout Standard
+
+The debugger can be started using the following command line.
+ (Assume the file you are debugging has the file name foo).
+\newline
+
+\newline
+
+\family sans
+\series bold
+sdcdb foo
+\newline
+
+\family default
+\series default
+
+\newline
+The debugger will look for the following files.
+\layout Itemize
+
+foo.c - the source file.
+\layout Itemize
+
+foo.cdb - the debugger symbol information file.
+\layout Itemize
+
+foo.ihx - the Intel hex format
+\begin_inset LatexCommand \index{Intel hex format}
+
+\end_inset
+
+ object file.
+\layout Section
+
+Command Line Options
+\layout Itemize
+
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-directory=<source file directory> this option can used to specify the directory
+ search list.
+ The debugger will look into the directory list specified for source, cdb
+ & ihx files.
+ The items in the directory list must be separated by ':', e.g.
+ if the source files can be in the directories /home/src1 and /home/src2,
+ the -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-directory option should be -
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-directory=/home/src1:/home/src2.
+ Note there can be no spaces in the option.
+
+\layout Itemize
+
+-cd <directory> - change to the <directory>.
+\layout Itemize
+
+-fullname - used by GUI front ends.
+\layout Itemize
+
+-cpu <cpu-type> - this argument is passed to the simulator please see the
+ simulator docs for details.
+\layout Itemize
+
+-X <Clock frequency > this options is passed to the simulator please see
+ the simulator docs for details.
+\layout Itemize
+
+-s <serial port file> passed to simulator see the simulator docs for details.
+\layout Itemize
+
+-S <serial in,out> passed to simulator see the simulator docs for details.
+\layout Itemize
+
+-k <port number> passed to simulator see the simulator docs for details.
+\layout Section
+
+Debugger Commands
+\layout Standard
+
+As mentioned earlier the command interface for the debugger has been deliberatel
+y kept as close the GNU debugger gdb, as possible.
+ This will help the integration with existing graphical user interfaces
+ (like ddd, xxgdb or xemacs) existing for the GNU debugger.
+ If you use a graphical user interface for the debugger you can skip this
+ section.
+\layout Subsubsection*
+
+break [line | file:line | function | file:function]
+\layout Standard
+
+Set breakpoint at specified line or function:
+\newline
+
+\newline
+
+\family sans
+\series bold
+sdcdb>break 100
+\newline
+sdcdb>break foo.c:100
+\newline
+sdcdb>break funcfoo
+\newline
+sdcdb>break foo.c:funcfoo
+\layout Subsubsection*
+
+clear [line | file:line | function | file:function ]
+\layout Standard
+
+Clear breakpoint at specified line or function:
+\newline
+
+\newline
+
+\family sans
+\series bold
+sdcdb>clear 100
+\newline
+sdcdb>clear foo.c:100
+\newline
+sdcdb>clear funcfoo
+\newline
+sdcdb>clear foo.c:funcfoo
+\layout Subsubsection*
+
+continue
+\layout Standard
+
+Continue program being debugged, after breakpoint.
+\layout Subsubsection*
+
+finish
+\layout Standard
+
+Execute till the end of the current function.
+\layout Subsubsection*
+
+delete [n]
+\layout Standard
+
+Delete breakpoint number 'n'.
+ If used without any option clear ALL user defined break points.
+\layout Subsubsection*
+
+info [break | stack | frame | registers ]
+\layout Itemize
+
+info break - list all breakpoints
+\layout Itemize
+
+info stack - show the function call stack.
+\layout Itemize
+
+info frame - show information about the current execution frame.
+\layout Itemize
+
+info registers - show content of all registers.
+\layout Subsubsection*
+
+step
+\layout Standard
+
+Step program until it reaches a different source line.
+ Note: pressing <return> repeats the last command.
+\layout Subsubsection*
+
+next
+\layout Standard
+
+Step program, proceeding through subroutine calls.
+\layout Subsubsection*
+
+run
+\layout Standard
+
+Start debugged program.
+\layout Subsubsection*
+
+ptype variable
+\layout Standard
+
+Print type information of the variable.
+\layout Subsubsection*
+
+print variable
+\layout Standard
+
+print value of variable.
+\layout Subsubsection*
+
+file filename
+\layout Standard
+
+load the given file name.
+ Note this is an alternate method of loading file for debugging.
+\layout Subsubsection*
+
+frame
+\layout Standard
+
+print information about current frame.
+\layout Subsubsection*
+
+set srcmode
+\layout Standard
+
+Toggle between C source & assembly source.
+\layout Subsubsection*
+
+! simulator command
+\layout Standard
+
+Send the string following '!' to the simulator, the simulator response is
+ displayed.
+ Note the debugger does not interpret the command being sent to the simulator,
+ so if a command like 'go' is sent the debugger can loose its execution
+ context and may display incorrect values.
+\layout Subsubsection*
+
+quit
+\layout Standard
+
+"Watch me now.
+ Iam going Down.
+ My name is Bobby Brown"
+\layout Section
+
+Interfacing with DDD
+\layout Comment
+
+The screenshot was converted from png to eps with:
+\begin_inset Quotes sld
+\end_inset
+
+bmeps -c -e8f -p3 ddd_example.png >ddd_example.eps
+\begin_inset Quotes srd
+\end_inset
+
+ which produces a pretty compact eps file which is free from compression
+ artifacts.
+\layout Comment
+
+The screenshot was included in sdccman.lyx cvs version 1.120 but later removed
+ as this broke the build system on Sourceforge (pdf-file was broken).
+\layout Standard
+
+The .eps File
+\size footnotesize
+
+\begin_inset LatexCommand \url{http://cvs.sourceforge.net/viewcvs.py/*checkout*/sdcc/sdcc/doc/figures/ddd_example.eps}
+
+\end_inset
+
+
+\size default
+ shows a screenshot of a debugging session with DDD
+\begin_inset LatexCommand \index{DDD (debugger)}
+
+\end_inset
+
+ (Unix only) on a simulated 8032.
+ 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
+\family sans
+\series bold
+
+\newline
+
+\newline
+sdcc -
+\family default
+\series default
+
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+
+\family sans
+\series bold
+-debug ddd_example.c
+\family default
+\series default
+
+\family sans
+\series bold
+
+\newline
+
+\family default
+\series default
+
+\newline
+and DDD was invoked with
+\family sans
+\series bold
+
+\newline
+
+\newline
+ddd -debugger 'sdcdb -cpu 8032 ddd_example'
+\layout Section
+
+Interfacing with XEmacs
+\begin_inset LatexCommand \index{XEmacs}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Emacs}
+
+\end_inset
+
+
+\layout Standard
+
+Two files (in emacs lisp) are provided for the interfacing with XEmacs,
+ sdcdb.el and sdcdbsrc.el.
+ These two files can be found in the $(prefix)/bin directory after the installat
+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):
+\newline
+
+\newline
+
+\family typewriter
+(load-file sdcdbsrc.el)
+\family default
+
+\newline
+
+\newline
+.xemacs is a lisp file so the () around the command is REQUIRED.
+ 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:
+\newline
+
+\newline
+
+\family sans
+\series bold
+ESC-x sdcdbsrc
+\family default
+\series default
+
+\newline
+
+\newline
+You will prompted to enter the file name to be debugged.
+
+\newline
+
+\newline
+The command line options that are passed to the simulator directly are bound
+ to default values in the file sdcdbsrc.el.
+ The variables are listed below, these values maybe changed as required.
+\layout Itemize
+
+sdcdbsrc-cpu-type '51
+\layout Itemize
+
+sdcdbsrc-frequency '11059200
+\layout Itemize
+
+sdcdbsrc-serial nil
+\layout Standard
+
+The following is a list of key mapping for the debugger interface.
+\layout Standard
+
+\SpecialChar ~
+
+\family typewriter
+
+\newline
+;;\SpecialChar ~
+Current Listing ::
+\newline
+;;key\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+binding\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-\SpecialChar ~
-------\SpecialChar ~
+-------\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
---------
+-------
\newline
;;
\newline
-;; n\SpecialChar ~
+;;\SpecialChar ~
+n\SpecialChar ~
+\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- sdcdb-next-from-src\SpecialChar ~
+sdcdb-next-from-src\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
SDCDB next command
\newline
-;; b\SpecialChar ~
+;;\SpecialChar ~
+b\SpecialChar ~
+\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- sdcdb-back-from-src\SpecialChar ~
+sdcdb-back-from-src\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
SDCDB back command
\newline
-;; c\SpecialChar ~
+;;\SpecialChar ~
+c\SpecialChar ~
+\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- sdcdb-cont-from-src\SpecialChar ~
+sdcdb-cont-from-src\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
SDCDB continue command
\newline
-;; s\SpecialChar ~
+;;\SpecialChar ~
+s\SpecialChar ~
+\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- sdcdb-step-from-src\SpecialChar ~
+sdcdb-step-from-src\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
SDCDB step command
\newline
-;; ?\SpecialChar ~
+;;\SpecialChar ~
+?\SpecialChar ~
+\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- sdcdb-whatis-c-sexp\SpecialChar ~
+sdcdb-whatis-c-sexp\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- buffer point
+\SpecialChar ~
+buffer point
\newline
-;; x\SpecialChar ~
+;;\SpecialChar ~
+x\SpecialChar ~
+\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- sdcdbsrc-delete\SpecialChar ~
+sdcdbsrc-delete\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+\SpecialChar ~
given or delete arg (C-u arg x)
\newline
-;; m\SpecialChar ~
+;;\SpecialChar ~
+m\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- sdcdbsrc-frame\SpecialChar ~
+\SpecialChar ~
+sdcdbsrc-frame\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
buffer point
\newline
-;; !\SpecialChar ~
+;;\SpecialChar ~
+!\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- sdcdbsrc-goto-sdcdb\SpecialChar ~
+\SpecialChar ~
+sdcdbsrc-goto-sdcdb\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
Goto the SDCDB output buffer
\newline
-;; p\SpecialChar ~
+;;\SpecialChar ~
+p\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- sdcdb-print-c-sexp\SpecialChar ~
+\SpecialChar ~
+sdcdb-print-c-sexp\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- buffer point
+\SpecialChar ~
+buffer point
\newline
-;; g\SpecialChar ~
+;;\SpecialChar ~
+g\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- sdcdbsrc-goto-sdcdb\SpecialChar ~
+\SpecialChar ~
+sdcdbsrc-goto-sdcdb\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
Goto the SDCDB output buffer
\newline
-;; t\SpecialChar ~
+;;\SpecialChar ~
+t\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- sdcdbsrc-mode\SpecialChar ~
+\SpecialChar ~
+sdcdbsrc-mode\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
Toggles Sdcdbsrc mode (turns it off)
\newline
-;;
+;;
+\newline
+;;\SpecialChar ~
+C-c\SpecialChar ~
+C-f\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+sdcdb-finish-from-src\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+SDCDB finish command
+\newline
+;;
+\newline
+;;\SpecialChar ~
+C-x\SpecialChar ~
+SPC\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+sdcdb-break\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+Set break for line with point
+\newline
+;;\SpecialChar ~
+ESC\SpecialChar ~
+t\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+sdcdbsrc-mode\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+Toggle Sdcdbsrc mode
+\newline
+;;\SpecialChar ~
+ESC\SpecialChar ~
+m\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+sdcdbsrc-srcmode\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+Toggle list mode
+\newline
+;;
+\newline
+
+\layout Chapter
+\pagebreak_top
+TIPS
+\layout Standard
+
+Here are a few guidelines that will help the compiler generate more efficient
+ code, some of the tips are specific to this compiler others are generally
+ good programming practice.
+\layout Itemize
+
+Use the smallest data type to represent your data-value.
+ If it is known in advance that the value is going to be less than 256 then
+ use an 'unsigned char' instead of a 'short' or 'int'.
+ Please note, that ANSI C requires both signed and unsigned chars to be
+ promoted to 'signed int' before doing any operation.
+ This promotion
+\begin_inset LatexCommand \index{type promotion}
+
+\end_inset
+
+ can be omitted, if the result is the same.
+ The effect of the promotion rules together with the sign-extension is often
+ surprising:
+\begin_deeper
+\layout Verse
+
+
+\family typewriter
+unsigned char uc = 0xfe;
+\newline
+if (uc * uc < 0) /* this is true! */
+\newline
+{
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+....
+\newline
+}
+\layout Standard
+
+
+\family typewriter
+uc * uc
+\family default
+ is evaluated as
+\family typewriter
+(int) uc * (int) uc = (int) 0xfe * (int) 0xfe = (int) 0xfc04 = -1024
+\family default
+.
+
+\newline
+Another one:
+\layout Verse
+
+
+\family typewriter
+(unsigned char) -12 / (signed char) -3 = ...
+\layout Standard
+
+No, the result is not 4:
+\layout Verse
+
+
+\family typewriter
+(int) (unsigned char) -12 / (int) (signed char) -3 =
+\newline
+(int) (unsigned char) 0xf4 / (int) (signed char) 0xfd =
+\newline
+(int) 0x00f4 / (int) 0xfffd =
+\newline
+(int) 0x00f4 / (int) 0xfffd =
+\newline
+(int) 244 / (int) -3 =
+\newline
+(int) -81 = (int) 0xffaf;
+\layout Standard
+
+Don't complain, that gcc gives you a different result.
+ gcc uses 32 bit ints, while SDCC uses 16 bit ints.
+ Therefore the results are different.
+\newline
+From
+\begin_inset Quotes sld
+\end_inset
+
+comp.lang.c FAQ
+\begin_inset Quotes srd
+\end_inset
+
+:
+\layout Quote
+
+If well-defined overflow characteristics are important and negative values
+ are not, or if you want to steer clear of sign-extension problems when
+ manipulating bits or bytes, use one of the corresponding unsigned types.
+ (Beware when mixing signed and unsigned values in expressions, though.)
+\newline
+Although character types (especially unsigned char) can be used as "tiny"
+ integers, doing so is sometimes more trouble than it's worth, due to unpredicta
+ble sign extension and increased code size.
+\end_deeper
+\layout Itemize
+
+Use unsigned when it is known in advance that the value is not going to
+ be negative.
+ This helps especially if you are doing division or multiplication, bit-shifting
+ or are using an array index.
+\layout Itemize
+
+NEVER jump into a LOOP.
+\layout Itemize
+
+Declare the variables to be local
+\begin_inset LatexCommand \index{local variables}
+
+\end_inset
+
+ whenever possible, especially loop control variables (induction).
+\layout Itemize
+
+Since the compiler does not always do implicit integral promotion, the programme
+r should do an explicit cast when integral promotion is required.
+\layout Itemize
+
+Reducing the size of division, multiplication & modulus operations can reduce
+ code size substantially.
+ Take the following code for example.
+\begin_deeper
+\layout Verse
+
+
+\family typewriter
+foobar(unsigned int p1, unsigned char ch)
+\newline
+{
\newline
-;; C-c C-f\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
\SpecialChar ~
- sdcdb-finish-from-src\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+unsigned char ch1 = p1 % ch ;
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-SDCDB finish command
+....
\newline
-;;
+}
+\layout Standard
+
+For the modulus operation the variable ch will be promoted to unsigned int
+ first then the modulus operation will be performed (this will lead to a
+ call to support routine _moduint()), and the result will be casted to a
+ char.
+ If the code is changed to
+\layout Verse
+
+
+\family typewriter
+foobar(unsigned int p1, unsigned char ch)
\newline
-;; C-x SPC\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- sdcdb-break\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-Set break for line with point
+{
\newline
-;; ESC t\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- sdcdbsrc-mode\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-Toggle Sdcdbsrc mode
+unsigned char ch1 = (unsigned char)p1 % ch ;
\newline
-;; ESC m\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- sdcdbsrc-srcmode\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
- Toggle list mode
+....
\newline
-;;
+}
+\layout Standard
+
+It would substantially reduce the code generated (future versions of the
+ compiler will be smart enough to detect such optimization opportunities).
+\end_deeper
+\layout Itemize
+
+Have a look at the assembly listing to get a
+\begin_inset Quotes sld
+\end_inset
+
+feeling
+\begin_inset Quotes srd
+\end_inset
+
+ for the code generation.
+\layout Section
+
+Tools
+\begin_inset LatexCommand \index{Tools}
+
+\end_inset
+
+ included in the distribution
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="12" columns="3">
+<features>
+<column alignment="center" valignment="top" leftline="true" width="0pt">
+<column alignment="center" valignment="top" leftline="true" width="0pt">
+<column alignment="left" valignment="top" leftline="true" rightline="true" width="0pt">
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Name
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Purpose
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Directory
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+uCsim
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Simulator for various architectures
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+sdcc/sim/ucsim
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+keil2sdcc.pl
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+header file conversion
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+sdcc/support/scripts
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+mh2h.c
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+header file conversion
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+sdcc/support/scripts
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+as-gbz80
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Assembler
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+sdcc/bin
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+as-z80
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Assembler
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+sdcc/bin
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+asx8051
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Assembler
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+sdcc/bin
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+sdcdb
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Simulator
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+sdcc/bin
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+aslink
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Linker
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+sdcc/bin
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+link-z80
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Linker
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+sdcc/bin
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+link-gbz80
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+Linker
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\family roman
+\series medium
+\shape up
+\size normal
+\emph off
+\bar no
+\noun off
+\color none
+sdcc/bin
+\end_inset
+</cell>
+</row>
+<row topline="true" bottomline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+packihx
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+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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+\layout Standard
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+ihx packer
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+\layout Standard
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+
+\end_inset
+
+
\newline
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+Documentation
+\begin_inset LatexCommand \index{Documentation}
+
+\end_inset
+
+ included in the distribution
+\layout Standard
+\align center
+
+\begin_inset Tabular
+<lyxtabular version="3" rows="10" columns="2">
+<features>
+<column alignment="left" valignment="top" leftline="true" width="0">
+<column alignment="left" valignment="top" leftline="true" rightline="true" width="0pt">
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+Subject / Title
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+
+\layout Standard
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+Where to get / filename
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+
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+SDCC Compiler User Guide
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+You're reading it right now
+\end_inset
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+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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+
+\layout Standard
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+Changelog of SDCC
+\end_inset
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+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
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+sdcc/Changelog
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+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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+ASXXXX
+\begin_inset LatexCommand \index{asXXXX (as-gbz80, as-hc08, asx8051, as-z80)}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Assembler documentation}
+
+\end_inset
+
+ Assemblers and ASLINK
+\begin_inset LatexCommand \index{aslink}
+
+\end_inset
+
+
+\begin_inset LatexCommand \index{Linker documentation}
+
+\end_inset
+
+ Relocating Linker
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
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+\layout Standard
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+sdcc/as/doc/asxhtm.html
+\end_inset
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+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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+\layout Standard
+
+SDCC regression test
+\begin_inset LatexCommand \index{Regression test}
+
+\end_inset
+
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
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+\layout Standard
+
+Notes on debugging with sdcdb
+\begin_inset LatexCommand \index{sdcdb (debugger)}
+
+\end_inset
+
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
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+Software simulator for microcontrollers
+\end_inset
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+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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\layout Standard
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+Temporary notes on the pic16
+\begin_inset LatexCommand \index{PIC16}
-Use the smallest data type to represent your data-value.
- If it is known in advance that the value is going to be less than 256 then
- use an 'unsigned char' instead of a 'short' or 'int'.
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- This promotion can be omitted, if the result is the same.
- The effect of the promotion rules together with the sign-extension is often
- supprising:
-\begin_deeper
-\layout Verse
+\end_inset
+ port
+\end_inset
+</cell>
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+sdcc/src/pic16/NOTES
+\end_inset
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+\layout Standard
+
+SDCC internal documentation (debugging file format)
+\end_inset
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+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
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-
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+
+\end_inset
+
+
\newline
-Another one:
-\layout Verse
+\layout Section
+
+Related open source tools
+\begin_inset LatexCommand \index{Related tools}
+
+\end_inset
+
+
+\layout Standard
+\align center
+
+\begin_inset Tabular
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+<features>
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+\layout Standard
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+Name
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+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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+
+\layout Standard
+
+Purpose
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+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
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+\layout Standard
+
+Where to get
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+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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+\layout Standard
+
+gpsim
+\begin_inset LatexCommand \index{gpsim (pic simulator)}
+
+\end_inset
+
+
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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+
+\layout Standard
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+PIC simulator
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+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\begin_inset LatexCommand \url{http://www.dattalo.com/gnupic/gpsim.html}
+
+\end_inset
+
+
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+gputils
+\begin_inset LatexCommand \index{gputils (pic tools)}
+
+\end_inset
+
+
+\end_inset
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+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+GNU PIC utilities
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+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
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+
+\layout Standard
+
+
+\begin_inset LatexCommand \url{http://sourceforge.net/projects/gputils}
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+\end_inset
+
+
+\end_inset
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+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+flP5
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+PIC programmer
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
+
+\layout Standard
+
+
+\begin_inset LatexCommand \url{http://freshmeat.net/projects/flp5/}
+
+\end_inset
+
+
+\end_inset
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+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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+
+\layout Standard
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+indent
+\begin_inset LatexCommand \index{indent (source formatting tool)}
+
+\end_inset
+
+
+\end_inset
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+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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+Formats C source - Master of the white spaces
+\end_inset
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+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
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-(int) 0x00f4 / (int) 0xfffd =
-\newline
-(int) 244 / (int) -3 =
-\newline
-(int) -81 = (int) 0xffaf;
-\layout Standard
+\begin_inset LatexCommand \url{http://directory.fsf.org/GNU/indent.html}
-Don't complain, that gcc gives you a different result.
- gcc uses 32 bit ints, while SDCC uses 16 bit ints.
- Therefore the results are different.
-\newline
-From
-\begin_inset Quotes sld
\end_inset
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-\begin_inset Quotes srd
-\end_inset
-:
-\layout Quote
+\end_inset
+</cell>
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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-If well-defined overflow characteristics are important and negative values
- are not, or if you want to steer clear of sign-extension problems when
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-\newline
-Although character types (especially unsigned char) can be used as "tiny"
- integers, doing so is sometimes more trouble than it's worth, due to unpredicta
-ble sign extension and increased code size.
-\end_deeper
-\layout Itemize
+\layout Standard
-Use unsigned when it is known in advance that the value is not going to
- be negative.
- This helps especially if you are doing division or multiplication, bit-shifting
- or are using an array index.
-\layout Itemize
+srecord
+\begin_inset LatexCommand \index{srecord (bin, hex, ... tool)}
-NEVER jump into a LOOP.
-\layout Itemize
+\end_inset
-Declare the variables to be local
-\begin_inset LatexCommand \index{local variables}
\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
- whenever possible, especially loop control variables (induction).
-\layout Itemize
+\layout Standard
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-\layout Itemize
+Object file conversion, checksumming, ...
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+\begin_inset Text
-Reducing the size of division, multiplication & modulus operations can reduce
- code size substantially.
- Take the following code for example.
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-\layout Verse
+\layout Standard
-\family typewriter
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-{
-\newline
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-\SpecialChar ~
-\SpecialChar ~
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-unsigned char ch1 = p1 % ch ;
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-....
-\newline
-}
-\layout Standard
+\begin_inset LatexCommand \url{http://sourceforge.net/projects/srecord}
-For the modulus operation the variable ch will be promoted to unsigned int
- first then the modulus operation will be performed (this will lead to a
- call to support routine _moduint()), and the result will be casted to a
- char.
- If the code is changed to
-\layout Verse
+\end_inset
-\family typewriter
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-\newline
-{
-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
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-\newline
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-\SpecialChar ~
-....
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+\end_inset
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+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
+
\layout Standard
-It would substantially reduce the code generated (future versions of the
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-\end_deeper
-\layout Itemize
+objdump
+\begin_inset LatexCommand \index{objdump (tool)}
-Have a look at the assembly listing to get a
-\begin_inset Quotes sld
\end_inset
-feeling
-\begin_inset Quotes srd
-\end_inset
- for the code generation.
-\layout Section
+\end_inset
+</cell>
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+\begin_inset Text
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-\begin_inset LatexCommand \index{Tools}
+\layout Standard
+Object file conversion, ...
\end_inset
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+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
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- included in the distribution
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-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0pt">
-<row topline="true" bottomline="true">
+Part of binutils (should be there anyway)
+\end_inset
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+</row>
+<row topline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-Name
+doxygen
+\begin_inset LatexCommand \index{doxygen (source documentation tool)}
+
+\end_inset
+
+
\end_inset
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<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-Purpose
+Source code documentation system
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-Directory
+
+\begin_inset LatexCommand \url{http://www.doxygen.org}
+
+\end_inset
+
+
\end_inset
</cell>
</row>
\layout Standard
-uCsim
+kdevelop
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-Simulator for various architectures
+IDE (has anyone tried integrating SDCC & sdcdb? Unix only)
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-sdcc/sim/ucsim
+
+\begin_inset LatexCommand \url{http://www.kdevelop.org}
+
+\end_inset
+
+
\end_inset
</cell>
</row>
\layout Standard
-keil2sdcc.pl
+splint
+\begin_inset LatexCommand \index{splint (syntax checking tool)}
+
+\end_inset
+
+
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-header file conversion
+Statically checks c sources (see
+\begin_inset LatexCommand \ref{lyx:more-pedantic-SPLINT}
+
+\end_inset
+
+)
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-sdcc/support/scripts
+
+\begin_inset LatexCommand \url{http://www.splint.org}
+
+\end_inset
+
+
\end_inset
</cell>
</row>
-<row topline="true">
+<row topline="true" bottomline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-mh2h.c
+ddd
+\begin_inset LatexCommand \index{ddd (debugger)}
+
+\end_inset
+
+
\end_inset
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<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-header file conversion
+Debugger, serves nicely as GUI to sdcdb
+\begin_inset LatexCommand \index{sdcdb (debugger)}
+
+\end_inset
+
+ (Unix only)
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-sdcc/support/scripts
+
+\begin_inset LatexCommand \url{http://www.gnu.org/software/ddd/}
+
+\end_inset
+
+
+\end_inset
+</cell>
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+
+\end_inset
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+
+\newline
+
+\layout Section
+
+Related documentation / recommended reading
+\layout Standard
+\align center
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+\begin_inset Tabular
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+<column alignment="center" valignment="top" leftline="true" rightline="true" width="0pt">
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+\layout Standard
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+Name
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\begin_inset Text
\layout Standard
-as-gbz80
+Subject / Title
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</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
+<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\begin_inset Text
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-Assembler
+Where to get
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</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
+</row>
+<row topline="true">
+<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
\bar no
\noun off
\color none
-sdcc/bin
+c-refcard.pdf
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-</row>
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<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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\layout Standard
-as-z80
-\end_inset
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-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+C Reference Card
+\begin_inset LatexCommand \index{C Reference card}
-\layout Standard
+\end_inset
-Assembler
+, 2 pages
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-sdcc/bin
+\begin_inset LatexCommand \url{http://refcards.com/refcards/c/index.html}
+
+\end_inset
+
+
\end_inset
</cell>
</row>
\layout Standard
-asx8051
+c-faq
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-Assembler
+C-FAQ-list
\end_inset
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<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-\family roman
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-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-sdcc/bin
+\begin_inset LatexCommand \url{http://www.eskimo.com/~scs/C-faq/top.html}
+
+\end_inset
+
+
\end_inset
</cell>
</row>
\layout Standard
-sdcdb
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-Simulator
+Latest datasheet of the target CPU
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-sdcc/bin
+vendor
\end_inset
</cell>
</row>
\layout Standard
-aslink
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-Linker
+Revision history of datasheet
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-sdcc/bin
+vendor
\end_inset
</cell>
</row>
-<row topline="true">
+<row topline="true" bottomline="true">
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\begin_inset Text
\layout Standard
-link-z80
+S.
+ S.
+ Muchnick
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
\layout Standard
-Linker
+Advanced Compiler Design and Implementation
\end_inset
</cell>
<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
\layout Standard
-
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-sdcc/bin
+bookstore (very dedicated, probably read other books first)
\end_inset
</cell>
</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+</lyxtabular>
+
+\end_inset
+
+
+\newline
+\layout Section
+
+Some Questions
\layout Standard
-link-gbz80
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+Some questions answered, some pointers given - it might be time to in turn
+ ask
+\emph on
+you
+\emph default
+ some questions:
+\layout Itemize
+
+can you solve your project with the selected microcontroller? Would you
+ find out early or rather late that your target is too small/slow/whatever?
+ Can you switch to a slightly better device if it doesn't fit?
+\layout Itemize
+
+should you solve the problem with an 8 bit CPU? Or would a 16/32 bit CPU
+ and/or another programming language be more adequate? Would an operating
+ system on the target device help?
+\layout Itemize
+
+if you solved the problem, will the marketing department be happy?
+\layout Itemize
+
+if the marketing department is happy, will customers be happy?
+\layout Itemize
+
+if you're the project manager, marketing department and maybe even the customer
+ in one person, have you tried to see the project from the outside?
+\layout Itemize
+
+is the project done if you think it is done? Or is just that other interface/pro
+tocol/feature/configuration/option missing? How about website, manual(s),
+ internationali(z|s)ation, packaging, labels, 2nd source for components,
+ electromagnetic compatability/interference, documentation for production,
+ production test software, update mechanism, patent issues?
+\layout Itemize
+is your project adequately positioned in that magic triangle: fame, fortune,
+ fun?
\layout Standard
-Linker
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+Maybe not all answers to these questions are known and some answers may
+ even be
+\emph on
+no
+\emph default
+, nevertheless knowing these questions may help you to avoid burnout
+\begin_inset Foot
+collapsed false
\layout Standard
+burnout is bad for electronic devices, programmers and motorcycle tyres
+\end_inset
+
+.
+ Chances are you didn't want to hear some of them...
+\layout Chapter
+
+Support
+\begin_inset LatexCommand \index{Support}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-sdcc/bin
\end_inset
-</cell>
-</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+
\layout Standard
-packihx
+SDCC has grown to be a large project.
+ The compiler alone (without the preprocessor, assembler and linker) is
+ well over 100,000 lines of code (blank stripped).
+ The open source nature of this project is a key to its continued growth
+ and support.
+ You gain the benefit and support of many active software developers and
+ end users.
+ Is SDCC perfect? No, that's why we need your help.
+ The developers take pride in fixing reported bugs.
+ 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.
+
+\layout Standard
+
+The SDCC project is hosted on the SDCC sourceforge site at
+\begin_inset LatexCommand \htmlurl{http://sourceforge.net/projects/sdcc}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+.
+ You'll find the complete set of mailing lists
+\begin_inset LatexCommand \index{Mailing list(s)}
-ihx packer
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+, forums, bug reporting system, patch submission
+\begin_inset LatexCommand \index{Patch submission}
+\end_inset
+
+ system, download
+\begin_inset LatexCommand \index{download}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-sdcc/bin
\end_inset
-</cell>
-</row>
-</lyxtabular>
+
+ area and Subversion code repository
+\begin_inset LatexCommand \index{cvs code repository}
\end_inset
+ there.
+\layout Section
+
+Reporting Bugs
+\begin_inset LatexCommand \index{Bug reporting}
-\newline
+\end_inset
-\layout Section
-Documentation
-\begin_inset LatexCommand \index{Documentation}
+\begin_inset LatexCommand \index{Reporting bugs}
\end_inset
- included in the distribution
-\layout Standard
-\align center
-\begin_inset Tabular
-<lyxtabular version="3" rows="10" columns="2">
-<features>
-<column alignment="left" valignment="top" leftline="true" width="0(null)">
-<column alignment="left" valignment="top" leftline="true" rightline="true" width="0pt">
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\layout Standard
+The recommended way of reporting bugs is using the infrastructure of the
+ sourceforge site.
+ You can follow the status of bug reports there and have an overview about
+ the known bugs.
\layout Standard
-Subject / Title
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+Bug reports are automatically forwarded to the developer mailing list and
+ will be fixed ASAP.
+ When reporting a bug, it is very useful to include a small test program
+ (the smaller the better) which reproduces the problem.
+ If you can isolate the problem by looking at the generated assembly code,
+ this can be very helpful.
+ Compiling your program with the -
+\begin_inset ERT
+status Collapsed
\layout Standard
-Where to get / filename
+\backslash
+/
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+-dumpall
+\begin_inset LatexCommand \index{-\/-dumpall}
-SDCC Compiler User Guide
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ option can sometimes be useful in locating optimization problems.
+ When reporting a bug please maker sure you:
+\layout Enumerate
-You're reading it right now
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+Attach the code you are compiling with SDCC.
+
+\layout Enumerate
-\layout Standard
+Specify the exact command you use to run SDCC, or attach your Makefile.
+
+\layout Enumerate
-Changelog of SDCC
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+Specify the SDCC version (type "
+\family sans
+\series bold
+sdcc -v
+\family default
+\series default
+"), your platform, and operating system.
+
+\layout Enumerate
-\layout Standard
+Provide an exact copy of any error message or incorrect output.
+
+\layout Enumerate
-sdcc/Changelog
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+Put something meaningful in the subject of your message.
+\layout Standard
+Please attempt to include these 5 important parts, as applicable, in all
+ requests for support or when reporting any problems or bugs with SDCC.
+ Though this will make your message lengthy, it will greatly improve your
+ 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!
\layout Standard
-ASXXXX Assemblers and ASLINK Relocating Linker
+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:
+\begin_inset LatexCommand \htmlurl{http://sourceforge.net/tracker/?group_id=599&atid=100599}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+.
+\layout Section
+
+Requesting Features
+\begin_inset LatexCommand \label{sub:Requesting-Features}
-sdcc/as/doc/asxhtm.html
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-SDCC regression test
-\begin_inset LatexCommand \index{Regression test}
+\begin_inset LatexCommand \index{Feature request}
\end_inset
+\begin_inset LatexCommand \index{Requesting features}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+
\layout Standard
-sdcc/doc/test_suite_spec.pdf
+Like bug reports feature requests are forwarded to the developer mailing
+ list.
+ This is the link for requesting features:
+\begin_inset LatexCommand \htmlurl{http://sourceforge.net/tracker/?group_id=599&atid=350599}
+
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+.
+\layout Section
+
+Submitting patches
\layout Standard
-Various notes
+Like bug reports contributed patches are forwarded to the developer mailing
+ list.
+ This is the link for submitting patches
+\begin_inset LatexCommand \index{Patch submission}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+:
+\begin_inset LatexCommand \url{http://sourceforge.net/tracker/?group_id=599&atid=300599}
-sdcc/doc/*
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+.
\layout Standard
-Notes on debugging with sdcdb
-\begin_inset LatexCommand \index{sdcdb (debugger)}
+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
+\family sans
+\series bold
+\begin_inset Quotes sld
\end_inset
-
+diff -Naur unmodified_directory modified_directory >my_changes.patch
+\begin_inset Quotes srd
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-
-sdcc/debugger/README
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+\family default
+\series default
+ will be fine, otherwise
+\family sans
+\series bold
-Software simulator for microcontrollers
+\begin_inset Quotes sld
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+diff -u sourcefile.c.orig sourcefile.c >my_changes.patch
+\begin_inset Quotes srd
+\end_inset
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-sdcc/sim/ucsim/doc
-\family default
\series default
-\shape default
-\size default
-\emph default
-\bar default
-\noun default
-\color default
-/index.html
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+
+\family default
+will do.
+\layout Section
+Getting Help
\layout Standard
-Temporary notes on the pic16
-\begin_inset LatexCommand \index{PIC16}
+These links should take you directly to the
+\begin_inset LatexCommand \url[Mailing lists]{http://sourceforge.net/mail/?group_id=599}
\end_inset
- port
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+
+\begin_inset Foot
+collapsed false
\layout Standard
-sdcc/src/pic16/NOTES
+Traffic on sdcc-devel and sdcc-user is about 100 mails/month each not counting
+ automated messages (mid 2003)
+\end_inset
+
+ and the
+\begin_inset LatexCommand \url[Forums]{http://sourceforge.net/forum/?group_id=599}
+
\end_inset
-</cell>
-</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+, lists
+\begin_inset LatexCommand \index{Mailing list(s)}
-SDCC internal documentation (debugging file format)
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+ and forums are archived and searchable so if you are lucky someone already
+ had a similar problem.
+ While mails to the lists themselves are delivered promptly their web front
+ end on sourceforge sometimes shows a severe time lag (up to several weeks),
+ if you're seriously using SDCC please consider subscribing to the lists.
+\layout Section
+
+ChangeLog
\layout Standard
-sdcc/doc/
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-cdbfileformat.pd
-\family default
-\series default
-\shape default
-\size default
-\emph default
-\bar default
-\noun default
-\color default
-f
-\end_inset
-</cell>
-</row>
-</lyxtabular>
+You can follow the status of the Subversion version
+\begin_inset LatexCommand \index{version}
\end_inset
+ of SDCC by watching the Changelog
+\begin_inset LatexCommand \index{Changelog}
+
+\end_inset
+ in the cvs-repository
\newline
-\layout Section
+\size footnotesize
-Related open source tools
-\begin_inset LatexCommand \index{Related tools}
+\begin_inset LatexCommand \htmlurl{http://svn.sourceforge.net/viewcvs.cgi/*checkout*/sdcc/trunk/sdcc/ChangeLog}
\end_inset
+.
+\layout Section
+
+Release policy
+\begin_inset LatexCommand \index{Release policy}
-\layout Standard
-\align center
+\end_inset
-\begin_inset Tabular
-<lyxtabular version="3" rows="11" columns="3">
-<features>
-<column alignment="center" valignment="top" leftline="true" width="0pt">
-<column alignment="block" valignment="top" leftline="true" width="30line%">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0pt">
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
\layout Standard
-Name
+Historically there often were long delays between official releases and
+ the sourceforge download area tends to get not updated at all.
+ Excuses in the past might have referred to problems with live range analysis,
+ 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
+\begin_inset LatexCommand \htmlurl[snap]{http://sdcc.sourceforge.net/snap.php}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+, and you can always build the very last version (hopefully with many bugs
+ fixed, and features added) from the source code available at
+\begin_inset LatexCommand \htmlurl[Source]{http://sdcc.sourceforge.net/snap.php#Source}
-Purpose
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+.
+\layout Section
+
+Examples
+\begin_inset LatexCommand \index{Examples}
-Where to get
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+
\layout Standard
-gpsim
-\begin_inset LatexCommand \index{gpsim (pic simulator)}
+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
+\begin_inset LatexCommand \url{http://sdccokr.dl9sec.de/}
\end_inset
+
+\emph default
+web site or at
+\begin_inset LatexCommand \url{http://www.pjrc.com/tech/8051/}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+.
+\layout Comment
+
+I did insert a reference to Paul's web site here although it seems rather
+ dedicated to a specific 8032 board (I think it's okay because it f.e.
+ shows LCD/Harddisc interface and has a free 8051 monitor.
+ Independent 8032 board vendors face hard competition of heavily subsidized
+ development boards anyway).
+\layout Comment
+
+Maybe we should include some links to real world applications.
+ Preferably pointer to pointers (one for each architecture) so this stays
+ manageable here?
+\layout Section
+
+Quality control
+\begin_inset LatexCommand \index{Quality control}
-PIC simulator
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+
\layout Standard
+The compiler is passed through nightly compile and build checks.
+ The so called
+\shape italic
+regression tests
+\shape default
-\begin_inset LatexCommand \url{http://www.dattalo.com/gnupic/gpsim.html}
+\begin_inset LatexCommand \index{Regression test}
\end_inset
+ check that SDCC itself compiles flawlessly on several platforms and checks
+ the quality of the code generated by SDCC by running the code through simulator
+s.
+ There is a separate document
+\shape italic
+test_suite.pdf
+\begin_inset LatexCommand \index{Test suite}
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+
+\shape default
+ about this.
\layout Standard
-gputils
-\begin_inset LatexCommand \index{gputils (pic tools)}
+You'll find the test code in the directory
+\shape italic
+sdcc/support/regression
+\shape default
+.
+ You can run these tests manually by running
+\family sans
+make
+\family default
+ in this directory (or f.e.
+
+\family sans
+\series bold
+
+\begin_inset Quotes sld
+\end_inset
+make test-mcs51
+\begin_inset Quotes srd
\end_inset
+\family default
+\series default
+ if you don't want to run the complete tests).
+ The test code might also be interesting if you want to look for examples
+\begin_inset LatexCommand \index{Examples}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ checking corner cases of SDCC or if you plan to submit patches
+\begin_inset LatexCommand \index{Patch submission}
-GNU PIC utilities
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+.
\layout Standard
+The pic port uses a different set of regression tests, you'll find them
+ in the directory
+\shape italic
+sdcc/src/regression
+\shape default
+.
+\layout Section
-\begin_inset LatexCommand \url{http://gputils.sourceforge.net/}
+Use of SDCC in Education
+\layout Standard
-\end_inset
+In short:
+\emph on
+highly
+\emph default
+ encouraged
+\begin_inset Foot
+collapsed false
+\layout Standard
+the phrase "use in education" might evoke the association "
+\emph on
+only
+\emph default
+ fit for use in education".
+ This connotation is not intended but nevertheless risked as the licensing
+ of SDCC makes it difficult to offer educational discounts
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+.
+ If your rationales are to:
+\layout Enumerate
-flP5
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+give students a chance to understand the
+\emph on
+complete
+\emph default
+ steps of code generation
+\layout Enumerate
-\layout Standard
+have a curriculum that can be extended for years.
+ Then you could use an fpga board as target and your curriculum will seamlessly
+ extend from logic synthesis (
+\begin_inset LatexCommand \url[http://www.opencores.org]{opencores.org}
-PIC programmer
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+,
+\begin_inset LatexCommand \url[Oregano]{http://www.oregano.at/ip/ip01.htm}
+\end_inset
-\begin_inset LatexCommand \url{http://digilander.libero.it/fbradasc/FLP5.html}
+), over assembly programming, to C to FPGA compilers (
+\begin_inset LatexCommand \url[FPGAC]{http://sf.net/projects/fpgac}
\end_inset
+) and to C.
+\layout Enumerate
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+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
+\begin_inset LatexCommand \url[SourceForge]{http://www.sf.net}
-\layout Standard
+\end_inset
-indent
-\begin_inset LatexCommand \index{indent (source formatting tool)}
+, following some
+\begin_inset LatexCommand \url[netiquette]{http://en.wikipedia.org/wiki/Netiquette}
\end_inset
+, understanding BSD/LGPL/GPL/Proprietary licensing, growth models of Open
+ Source Software, CPU simulation, compiler regression tests
+\begin_inset LatexCommand \index{Regression test}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+.
+
+\newline
+And if there should be a shortage of ideas then you can always point students
+ to the ever-growing feature request list
+\begin_inset LatexCommand \htmlurl{http://sourceforge.net/tracker/?group_id=599&atid=350599}
-Formats C source - Master of the white spaces
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
+.
+\layout Enumerate
-\begin_inset LatexCommand \url{http://home.hccnet.nl/d.ingamells/beautify.html}
+not tie students to a specific host platform and instead allow them to use
+ a host platform of
+\emph on
+their
+\emph default
+ choice (among them Alpha, i386, i386_64, MacOs, Mips, Sparc, Windows and
+ eventually
+\begin_inset LatexCommand \url[OLPC]{http://wiki.laptop.org/wiki/One_Laptop_per_Child}
\end_inset
+)
+\layout Enumerate
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+not encourage students to use illegal copies of educational software
+\layout Enumerate
-\layout Standard
+be immune to licensing/availability/price changes of the chosen tool chain
+\layout Enumerate
-srecord
-\begin_inset LatexCommand \index{srecord (tool)}
+be able to change to a new target platform without having to adopt a new
+ tool chain
+\layout Enumerate
-\end_inset
+have complete control over and insight into the tool chain
+\layout Enumerate
+make your students aware about the pros and cons of open source software
+ development
+\layout Enumerate
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+give back to the public as you are probably at least partially publically
+ funded
+\layout Enumerate
+give students a chance to publically prove their skills and to possibly
+ see a world wide impact
\layout Standard
-Object file conversion, checksumming, ...
+then SDCC is probably among the first choices.
+ Well, probably SDCC might be the only choice.
+\layout Chapter
+\pagebreak_top
+SDCC Technical Data
+\layout Section
+
+Optimizations
+\begin_inset LatexCommand \index{Optimizations}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+
\layout Standard
+SDCC performs a host of standard optimizations in addition to some MCU specific
+ optimizations.
+
+\layout Subsection
-\begin_inset LatexCommand \url{http://srecord.sourceforge.net/}
+Sub-expression Elimination
+\begin_inset LatexCommand \index{Subexpression elimination}
\end_inset
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
\layout Standard
-objdump
-\begin_inset LatexCommand \index{objdump (tool)}
+The compiler does local and
+\emph on
+g
+\emph default
+lobal
+\emph on
+c
+\emph default
+ommon
+\emph on
+s
+\emph default
+ubexpression
+\emph on
+e
+\emph default
+limination, e.g.:
+\layout Verse
-\end_inset
+\family typewriter
+i = x + y + 1;
+\newline
+j = x + y;
+\layout Standard
+
+will be translated to
+\layout Verse
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\family typewriter
+iTemp = x + y;
+\newline
+i = iTemp + 1;
+\newline
+j = iTemp;
\layout Standard
-Object file conversion, ...
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+Some subexpressions are not as obvious as the above example, e.g.:
+\layout Verse
+
+\family typewriter
+a->b[i].c = 10;
+\newline
+a->b[i].d = 11;
\layout Standard
-Part of binutils (should be there anyway)
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+In this case the address arithmetic a->b[i] will be computed only once;
+ the equivalent code in C would be.
+\layout Verse
+
+\family typewriter
+iTemp = a->b[i];
+\newline
+iTemp.c = 10;
+\newline
+iTemp.d = 11;
\layout Standard
-doxygen
-\begin_inset LatexCommand \index{doxygen (source documentation tool)}
+The compiler will try to keep these temporary variables in registers.
+\layout Subsection
+
+Dead-Code Elimination
+\begin_inset LatexCommand \index{Dead-code elimination}
\end_inset
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\layout Verse
-\layout Standard
-Source code documentation system
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+\family typewriter
+int global;
+\newline
+\newline
+void f () {
+\newline
+\SpecialChar ~
+\SpecialChar ~
+int i;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+i = 1; \SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* dead store */
+\newline
+\SpecialChar ~
+\SpecialChar ~
+global = 1;\SpecialChar ~
+/* dead store */
+\newline
+\SpecialChar ~
+\SpecialChar ~
+global = 2;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+return;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+global = 3;\SpecialChar ~
+/* unreachable */
+\newline
+}
\layout Standard
+will be changed to
+\layout Verse
-\begin_inset LatexCommand \url{http://www.doxygen.org}
-\end_inset
+\family typewriter
+int global;
+\newline
+
+\newline
+void f () {
+\newline
+\SpecialChar ~
+\SpecialChar ~
+global = 2;
+\newline
+}
+\layout Subsection
+Copy-Propagation
+\begin_inset LatexCommand \index{Copy propagation}
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-kdevelop
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\layout Verse
+
+\family typewriter
+int f() {
+\newline
+\SpecialChar ~
+\SpecialChar ~
+int i, j;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+i = 10;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+j = i;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+return j;
+\newline
+}
\layout Standard
-IDE (has anyone tried integrating SDCC & sdcdb? Unix only)
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+will be changed to
+\layout Verse
+
+\family typewriter
+int f() {
+\newline
+\SpecialChar ~
+\SpecialChar ~
+int i, j;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+i = 10;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+j = 10;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+return 10;
+\newline
+}
\layout Standard
+Note: the dead stores created by this copy propagation will be eliminated
+ by dead-code elimination.
+\layout Subsection
-\begin_inset LatexCommand \url{http://www.kdevelop.org}
+Loop Optimizations
+\begin_inset LatexCommand \index{Loop optimization}
\end_inset
+\begin_inset LatexCommand \label{sub:Loop-Optimizations}
+
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+
\layout Standard
-splint
-\begin_inset LatexCommand \index{splint (syntax checking tool)}
+Two types of loop optimizations are done by SDCC
+\emph on
+loop invariant
+\emph default
+ lifting and
+\emph on
+ strength reduction
+\emph default
+ of loop induction variables.
+ In addition to the strength reduction the optimizer marks the induction
+ variables and the register allocator tries to keep the induction variables
+ in registers for the duration of the loop.
+ Because of this preference of the register allocator
+\begin_inset LatexCommand \index{Register allocation}
\end_inset
+, loop induction optimization causes an increase in register pressure, which
+ may cause unwanted spilling of other temporary variables into the stack
+\begin_inset LatexCommand \index{stack}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-Statically checks c sources
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+ / data space.
+ The compiler will generate a warning message when it is forced to allocate
+ extra space either on the stack or data space.
+ If this extra space allocation is undesirable then induction optimization
+ can be eliminated either for the entire source file (with -
+\begin_inset ERT
+status Collapsed
\layout Standard
-
-\begin_inset LatexCommand \url{http://www.splint.org}
-
+\backslash
+/
\end_inset
+-noinduction option) or for a given function only using #pragma\SpecialChar ~
+noinduction
+\begin_inset LatexCommand \index{\#pragma noinduction}
\end_inset
-</cell>
-</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-
-ddd
-\begin_inset LatexCommand \index{ddd (debugger)}
-\end_inset
+.
+\newline
+\newline
+Loop Invariant:
+\layout Verse
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\family typewriter
+for (i = 0 ; i < 100 ; i ++)
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+f += k + l;
\layout Standard
-Debugger, serves nicely as GUI to sdcdb
-\begin_inset LatexCommand \index{sdcdb (debugger)}
-
-\end_inset
+changed to
+\layout Verse
- (Unix only)
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+\family typewriter
+itemp = k + l;
+\newline
+for (i = 0; i < 100; i++)
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+f += itemp;
\layout Standard
+As mentioned previously some loop invariants are not as apparent, all static
+ address computations are also moved out of the loop.
+\newline
-\begin_inset LatexCommand \url{http://www.gnu.org/software/ddd/}
-
-\end_inset
-
+\newline
+Strength Reduction
+\begin_inset LatexCommand \index{Strength reduction}
\end_inset
-</cell>
-</row>
-</lyxtabular>
-\end_inset
+, this optimization substitutes an expression by a cheaper expression:
+\layout Verse
+\family typewriter
+for (i=0;i < 100; i++)
\newline
-
-\layout Section
-
-Related documentation / recommended reading
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ar[i*5] = i*3;
\layout Standard
-\align center
-
-\begin_inset Tabular
-<lyxtabular version="3" rows="6" columns="3">
-<features>
-<column alignment="center" valignment="top" leftline="true" width="0pt">
-<column alignment="block" valignment="top" leftline="true" width="30line%">
-<column alignment="center" valignment="top" leftline="true" rightline="true" width="0pt">
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+changed to
+\layout Verse
-Name
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\family typewriter
+itemp1 = 0;
+\newline
+itemp2 = 0;
+\newline
+for (i=0;i< 100;i++) {
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ar[itemp1] = itemp2;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+itemp1 += 5;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+itemp2 += 3;
+\newline
+}
\layout Standard
-Subject / Title
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
+The more expensive multiplication
+\begin_inset LatexCommand \index{Multiplication}
-Where to get
\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+ is changed to a less expensive addition.
+\layout Subsection
+Loop Reversing
+\begin_inset LatexCommand \index{Loop reversing}
-\family roman
-\series medium
-\shape up
-\size normal
-\emph off
-\bar no
-\noun off
-\color none
-c-refcard.pdf
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-C Reference Card
-\begin_inset LatexCommand \index{C Reference card}
+\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
+\begin_inset Quotes eld
\end_inset
-, 2 pages
+decrement and jump if not zero
+\begin_inset Quotes erd
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-
-\begin_inset LatexCommand \url{http://www.refcards.com/about/c.html}
-
-\end_inset
+ instruction.
+ SDCC checks for the following criterion to determine if a loop is reversible
+ (note: more sophisticated compilers use data-dependency analysis to make
+ this determination, SDCC uses a more simple minded analysis).
+\layout Itemize
+The 'for' loop is of the form
+\newline
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+\newline
-\layout Standard
+\family typewriter
+for(<symbol> = <expression>; <sym> [< | <=] <expression>; [<sym>++ | <sym>
+ += 1])
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+<for body>
+\layout Itemize
-c-faq
+The <for body> does not contain
+\begin_inset Quotes eld
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+continue
+\begin_inset Quotes erd
+\end_inset
-C-FAQ-list
+ or 'break
+\begin_inset Quotes erd
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+.
+\layout Itemize
+All goto's are contained within the loop.
+\layout Itemize
-\begin_inset LatexCommand \url{http://www.eskimo.com/~scs/C-faq/top.html}
+No function calls within the loop.
+\layout Itemize
-\end_inset
+The loop control variable <sym> is not assigned any value within the loop
+\layout Itemize
+The loop control variable does NOT participate in any arithmetic operation
+ within the loop.
+\layout Itemize
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+There are NO switch statements in the loop.
+\layout Subsection
+Algebraic Simplifications
\layout Standard
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
+SDCC does numerous algebraic simplifications, the following is a small sub-set
+ of these optimizations.
+\layout Verse
-Latest datasheet of the target CPU
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+\family typewriter
+i = j + 0;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ /* changed to: */\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ i = j;
+\newline
+i /= 2;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ /* changed to: */\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ i >>= 1;
+\newline
+i = j - j;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ /* changed to: */\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ i = 0;
+\newline
+i = j / 1;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ /* changed to: */\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ i = j;
\layout Standard
-vendor
-\end_inset
-</cell>
-</row>
-<row topline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
+Note the subexpressions
+\begin_inset LatexCommand \index{Subexpression}
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-
-\layout Standard
-Revision history of datasheet
-\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
+ given above are generally introduced by macro expansions or as a result
+ of copy/constant propagation.
+\layout Subsection
-\layout Standard
+'switch' Statements
+\begin_inset LatexCommand \label{sub:'switch'-Statements}
-vendor
\end_inset
-</cell>
-</row>
-<row topline="true" bottomline="true">
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
-\layout Standard
-S.
- S.
- Muchnick
+\begin_inset LatexCommand \index{switch statement}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
-\begin_inset Text
+
\layout Standard
-Advanced Compiler Design and Implementation
+SDCC can optimize switch statements to jump tables
+\begin_inset LatexCommand \index{jump tables}
+
\end_inset
-</cell>
-<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
-\begin_inset Text
-\layout Standard
+.
+ It makes the decision based on an estimate of the generated code size.
+ SDCC is quite liberal in the requirements for jump table generation:
+\layout Itemize
-bookstore (very dedicated, probably read other books first)
-\end_inset
-</cell>
-</row>
-</lyxtabular>
+The labels need not be in order, and the starting number need not be one
+ or zero, the case labels are in numerical sequence or not too many case
+ labels are missing.
+\begin_deeper
+\layout Verse
-\end_inset
+\family typewriter
+switch(i) {\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
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+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+switch (i) {
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 4: ...\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
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+\SpecialChar ~
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+\SpecialChar ~
+\SpecialChar ~
+case 0: ...
+
+\newline
+\SpecialChar ~
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+\SpecialChar ~
+case 5: ...\SpecialChar ~
+\SpecialChar ~
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+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 1: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 3: ...\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
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+\SpecialChar ~
\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 6: ...\SpecialChar ~
+\SpecialChar ~
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+case 3: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 7: ...\SpecialChar ~
+\SpecialChar ~
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+\SpecialChar ~
+case 4: ...
+
+\newline
+\SpecialChar ~
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+\SpecialChar ~
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+case 5: ...
+
+\newline
+\SpecialChar ~
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+\SpecialChar ~
+case 9: ...\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 6: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 10: ...\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 7: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 11: ...\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+case 8: ...
+
+\newline
+}\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+}
+\layout Standard
-\layout Section
-
-Some Questions
-\layout Standard
-
-Some questions answered, some pointers given - it might be time to in turn
- ask
-\emph on
-you
-\emph default
- some questions:
-\layout Itemize
-
-can you solve your project with the selected microcontroller? Would you
- find out early or rather late that your target is too small/slow/whatever?
- Can you switch to a slightly better device if it doesn't fit?
-\layout Itemize
-
-should you solve the problem with an 8 bit CPU? Or would a 16/32 bit CPU
- and/or another programming language be more adequate? Would an operating
- system on the target device help?
-\layout Itemize
-
-if you solved the problem, will the marketing department be happy?
-\layout Itemize
-
-if the marketing department is happy, will customers be happy?
+Both the above switch statements will be implemented using a jump-table.
+ The example to the right side is slightly more efficient as the check for
+ the lower boundary of the jump-table is not needed.
+\end_deeper
\layout Itemize
-if you're the project manager, marketing department and maybe even the customer
- in one person, have you tried to see the project from the outside?
+The number of case labels is not larger than supported by the target architectur
+e.
\layout Itemize
-is the project done if you think it is done? Or is just that other interface/pro
-tocol/feature/configuration/option missing? How about website, manual(s),
- internationali(z|s)ation, packaging, labels, 2nd source for components,
- electromagnetic compatability/interference, documentation for production,
- production test software, update mechanism, patent issues?
+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.
+
\layout Itemize
-is your project adequately positioned in that magic triangle: fame, fortune,
- fun?
-\layout Standard
-
-Maybe not all answers to these questions are known and some answers may
- even be
-\emph on
-no
-\emph default
-, nevertheless knowing these questions may help you to avoid burnout
-\begin_inset Foot
-collapsed false
-
+If the starting number is not zero and a check for the lower boundary of
+ the jump-table can thus be eliminated SDCC might insert dummy cases 0,
+ ...
+ .
\layout Standard
-burnout is bad for electronic devices, programmers and motorcycle tyres
-\end_inset
-
-.
- Chances are you didn't want to hear some of them...
-\layout Chapter
-
-Support
-\begin_inset LatexCommand \index{Support}
-
-\end_inset
-
+Switch statements which have large gaps in the numeric sequence or those
+ that have too many case labels can be split into more than one switch statement
+ for efficient code generation, e.g.:
+\layout Verse
-\layout Standard
-SDCC has grown to be a large project.
- The compiler alone (without the preprocessor, assembler and linker) is
- well over 100,000 lines of code (blank stripped).
- The open source nature of this project is a key to its continued growth
- and support.
- You gain the benefit and support of many active software developers and
- end users.
- Is SDCC perfect? No, that's why we need your help.
- The developers take pride in fixing reported bugs.
- 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.
+\family typewriter
+switch (i) {
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 1: ...
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 2: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 3: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 4: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 5: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 6: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 7: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 101: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 102: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 103: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 104: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 105: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 106: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 107: ...
+
+\newline
+}
\layout Standard
-The SDCC project is hosted on the SDCC sourceforge site at
-\begin_inset LatexCommand \htmlurl{http://sourceforge.net/projects/sdcc}
-
-\end_inset
-
-.
- You'll find the complete set of mailing lists
-\begin_inset LatexCommand \index{Mailing list}
-
-\end_inset
-
-, forums, bug reporting system, patch submission
-\begin_inset LatexCommand \index{Patch submission}
-
-\end_inset
-
- system, download
-\begin_inset LatexCommand \index{download}
-
-\end_inset
-
- area and cvs code repository
-\begin_inset LatexCommand \index{cvs code repository}
-
-\end_inset
-
- there.
-\layout Section
-
-Reporting Bugs
-\begin_inset LatexCommand \index{Bug reporting}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{Reporting bugs}
-
-\end_inset
-
-
-\layout Standard
-
-The recommended way of reporting bugs is using the infrastructure of the
- sourceforge site.
- You can follow the status of bug reports there and have an overview about
- the known bugs.
-\layout Standard
+If the above switch statement is broken down into two switch statements
+\layout Verse
-Bug reports are automatically forwarded to the developer mailing list and
- will be fixed ASAP.
- When reporting a bug, it is very useful to include a small test program
- (the smaller the better) which reproduces the problem.
- If you can isolate the problem by looking at the generated assembly code,
- this can be very helpful.
- Compiling your program with the -
-\begin_inset ERT
-status Collapsed
+\family typewriter
+switch (i) {
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 1: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 2: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 3: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 4: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 5: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 6: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 7: ...
+
+\newline
+}
\layout Standard
-\backslash
-/
-\end_inset
-
--dumpall
-\begin_inset LatexCommand \index{-\/-dumpall}
-
-\end_inset
+and
+\layout Verse
- option can sometimes be useful in locating optimization problems.
- When reporting a bug please maker sure you:
-\layout Enumerate
-Attach the code you are compiling with SDCC.
+\family typewriter
+switch (i) {
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 101: ...
-\layout Enumerate
-
-Specify the exact command you use to run SDCC, or attach your Makefile.
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 102: ...
-\layout Enumerate
-
-Specify the SDCC version (type "
-\family sans
-\series bold
-sdcc -v
-\family default
-\series default
-"), your platform, and operating system.
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 103: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 104: ...
-\layout Enumerate
-
-Provide an exact copy of any error message or incorrect output.
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 105: ...
-\layout Enumerate
-
-Put something meaningful in the subject of your message.
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 106: ...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+case 107: ...
+
+\newline
+}
\layout Standard
-Please attempt to include these 5 important parts, as applicable, in all
- requests for support or when reporting any problems or bugs with SDCC.
- Though this will make your message lengthy, it will greatly improve your
- 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!
+then both the switch statements will be implemented using jump-tables whereas
+ the unmodified switch statement will not be.
+\layout Comment
+
+There might be reasons which SDCC cannot know about to either favour or
+ not favour jump tables.
+ If the target system has to be as quick for the last switch case as for
+ the first (pro jump table), or if the switch argument is known to be zero
+ in the majority of the cases (contra jump table).
\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:
-\begin_inset LatexCommand \htmlurl{http://sourceforge.net/tracker/?group_id=599&atid=100599}
+The pragma nojtbound
+\begin_inset LatexCommand \index{\#pragma nojtbound}
\end_inset
-.
-\layout Section
-
-Requesting Features
-\begin_inset LatexCommand \label{sub:Requesting-Features}
+ can be used to turn off checking the
+\emph on
+j
+\emph default
+ump
+\emph on
+t
+\emph default
+able
+\emph on
+bound
+\emph default
+aries.
+ It has no effect if a default label is supplied.
+ Use of this pragma is dangerous: if the switch
+\begin_inset LatexCommand \index{switch statement}
\end_inset
+ argument is not matched by a case statement the processor will happily
+ jump into Nirvana.
+\layout Subsection
-\begin_inset LatexCommand \index{Feature request}
+Bit-shifting Operations
+\begin_inset LatexCommand \index{Bit shifting}
\end_inset
+.
+\layout Standard
-\begin_inset LatexCommand \index{Requesting features}
-
-\end_inset
+Bit shifting is one of the most frequently used operation in embedded programmin
+g.
+ SDCC tries to implement bit-shift operations in the most efficient way
+ possible, e.g.:
+\layout Verse
+\family typewriter
+unsigned char i;
+\newline
+...
+
+\newline
+i >>= 4;
+\newline
+...
\layout Standard
-Like bug reports feature requests are forwarded to the developer mailing
- list.
- This is the link for requesting features:
-\begin_inset LatexCommand \htmlurl{http://sourceforge.net/tracker/?group_id=599&atid=350599}
-
-\end_inset
+generates the following code:
+\layout Verse
-.
-\layout Section
-Submitting patches
+\family typewriter
+mov\SpecialChar ~
+ a,_i
+\newline
+swap a
+\newline
+anl\SpecialChar ~
+ a,#0x0f
+\newline
+mov\SpecialChar ~
+ _i,a
\layout Standard
-Like bug reports contributed patches are forwarded to the developer mailing
- list.
- This is the link for submitting patches
-\begin_inset LatexCommand \index{Patch submission}
+In general SDCC will never setup a loop if the shift count is known.
+ Another example:
+\layout Verse
-\end_inset
-:
-\begin_inset LatexCommand \url{http://sourceforge.net/tracker/?group_id=599&atid=300599}
+\family typewriter
+unsigned int i;
+\newline
+...
+
+\newline
+i >>= 9;
+\newline
+...
+\layout Standard
-\end_inset
+will generate:
+\layout Verse
-.
-\layout Standard
-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
-\family sans
-\series bold
+mov\SpecialChar ~
+\SpecialChar ~
+a,(_i + 1)
+\newline
+mov\SpecialChar ~
+\SpecialChar ~
+(_i + 1),#0x00
+\newline
+clr\SpecialChar ~
+\SpecialChar ~
+c
+\newline
+rrc\SpecialChar ~
+\SpecialChar ~
+a
+\newline
+mov\SpecialChar ~
+\SpecialChar ~
+_i,a
+\layout Subsection
-\begin_inset Quotes sld
-\end_inset
+Bit-rotation
+\begin_inset LatexCommand \index{Bit rotation}
-diff -Naur unmodified_directory modified_directory >my_changes.patch
-\begin_inset Quotes srd
\end_inset
-\family default
-\series default
- will be fine, otherwise
-\family sans
-\series bold
+\layout Standard
-\begin_inset Quotes sld
-\end_inset
+A special case of the bit-shift operation is bit rotation
+\begin_inset LatexCommand \index{rotating bits}
-diff -u sourcefile.c.orig sourcefile.c >my_changes.patch
-\begin_inset Quotes srd
\end_inset
+, SDCC recognizes the following expression to be a left bit-rotation:
+\layout Verse
+
+\family typewriter
+\series bold
+unsigned
\series default
+\SpecialChar ~
+\SpecialChar ~
+char i;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+/* unsigned is needed for rotation */
+\newline
+...
+\newline
+i = ((i << 1) | (i >> 7));
\family default
-will do.
-\layout Section
-
-Getting Help
-\layout Standard
-
-These links should take you directly to the
-\begin_inset LatexCommand \url[Mailing lists]{http://sourceforge.net/mail/?group_id=599}
-
-\end_inset
+\newline
-\begin_inset Foot
-collapsed false
-
-\layout Standard
-
-Traffic on sdcc-devel and sdcc-user is about 100 mails/month each not counting
- automated messages (mid 2003)
-\end_inset
-
- and the
-\begin_inset LatexCommand \url[Forums]{http://sourceforge.net/forum/?group_id=599}
-
-\end_inset
-
-, lists and forums are archived and searchable so if you are lucky someone
- already had a similar problem.
-\layout Section
-
-ChangeLog
+\family typewriter
+...
\layout Standard
-You can follow the status of the cvs version
-\begin_inset LatexCommand \index{version}
-
-\end_inset
-
- of SDCC by watching the Changelog
-\begin_inset LatexCommand \index{Changelog}
+will generate the following code:
+\layout Verse
-\end_inset
- in the cvs-repository
+\family typewriter
+mov\SpecialChar ~
+\SpecialChar ~
+a,_i
\newline
+rl\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+a
+\newline
+mov\SpecialChar ~
+\SpecialChar ~
+_i,a
+\layout Standard
-\size footnotesize
-
-\begin_inset LatexCommand \htmlurl{http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/*checkout*/sdcc/sdcc/ChangeLog?rev=HEAD&content-type=text/plain}
-
-\end_inset
-
-.
-\layout Section
-
-Release policy
-\begin_inset LatexCommand \index{Release policy}
+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.:
+\layout Verse
-\end_inset
+\family typewriter
+i = ((i >> 7) | (i << 1)); /* left-bit rotation */
+\layout Subsection
+Nibble and Byte Swapping
\layout Standard
-Historically there often were long delays between official releases and
- the sourceforge download area tends to get not updated at all.
- Excuses in the past might have referred to problems with live range analysis,
- 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
-\begin_inset LatexCommand \htmlurl[snap]{http://sdcc.sourceforge.net/snap.php}
+Other special cases of the bit-shift operations are nibble or byte swapping
+\begin_inset LatexCommand \index{swapping nibbles/bytes}
\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
-\begin_inset LatexCommand \htmlurl[Source]{http://sdcc.sourceforge.net/snap.php#Source}
-
-\end_inset
+, SDCC recognizes the following expressions:
+\layout Verse
-.
-\layout Section
-Examples
-\begin_inset LatexCommand \index{Examples}
+\family typewriter
+\series bold
+unsigned
+\series default
+\SpecialChar ~
+\SpecialChar ~
+char i;
+\newline
-\end_inset
+\series bold
+unsigned
+\series default
+\SpecialChar ~
+\SpecialChar ~
+int j;
+\newline
+...
+
+\newline
+i = ((i << 4) | (i >> 4));
+\family default
+\newline
+\family typewriter
+j = ((j << 8) | (j >> 8));
\layout Standard
-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
-\begin_inset LatexCommand \url{http://www.qsl.net/dl9sec/SDCC_OKR.html}
+and generates a swap instruction for the nibble swapping
+\begin_inset LatexCommand \index{Nibble swapping}
\end_inset
-
-\emph default
-web site or at
-\begin_inset LatexCommand \url{http://www.pjrc.com/tech/8051/}
+ or move instructions for the byte swapping
+\begin_inset LatexCommand \index{Byte swapping}
\end_inset
.
-\layout Comment
-
-I did insert a reference to Paul's web site here although it seems rather
- dedicated to a specific 8032 board (I think it's okay because it f.e.
- shows LCD/Harddisc interface and has a free 8051 monitor.
- Independent 8032 board vendors face hard competition of heavily subsidized
- development boards anyway).
-\layout Comment
-
-Maybe we should include some links to real world applications.
- Preferably pointer to pointers (one for each architecture) so this stays
- manageable here?
-\layout Section
-
-Quality control
-\begin_inset LatexCommand \index{Quality control}
-
+ The
+\begin_inset Quotes sld
\end_inset
+j
+\begin_inset Quotes srd
+\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
+\emph on
+signed
+\emph default
+ integer you have to cast to
+\family typewriter
+(unsigned int)
+\family default
+ first.
\layout Standard
-The compiler is passed through nightly compile and build checks.
- The so called
-\shape italic
-regression tests
-\shape default
+Note that SDCC stores numbers in little-endian
+\begin_inset Foot
+collapsed false
-\begin_inset LatexCommand \index{Regression test}
+\layout Standard
-\end_inset
+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
+\emph on
+dptr
+\emph default
- check that SDCC itself compiles flawlessly on several platforms and checks
- the quality of the code generated by SDCC by running the code through simulator
-s.
- There is a separate document
-\shape italic
-test_suite.pdf
-\begin_inset LatexCommand \index{Test suite}
+\begin_inset LatexCommand \index{DPTR}
\end_inset
-
-\shape default
- about this.
-\layout Standard
-
-You'll find the test code in the directory
-\shape italic
-sdcc/support/regression
-\shape default
-.
- You can run these tests manually by running
-\family sans
-make
-\family default
- in this directory (or f.e.
+-datapointer
+\emph on
-\family sans
-\series bold
-
-\begin_inset Quotes sld
-\end_inset
-
-make test-mcs51
-\begin_inset Quotes srd
+\emph default
+so little-endian is the more efficient byte order.
\end_inset
-\family default
-\series default
- if you don't want to run the complete tests).
- The test code might also be interesting if you want to look for examples
-\begin_inset LatexCommand \index{Examples}
-
-\end_inset
-
- checking corner cases of SDCC or if you plan to submit patches
-\begin_inset LatexCommand \index{Patch submission}
+\begin_inset LatexCommand \index{little-endian}
\end_inset
-.
-\layout Standard
-
-The pic port uses a different set of regression tests, you'll find them
- in the directory
-\shape italic
-sdcc/src/regression
-\shape default
-.
-\layout Chapter
-\pagebreak_top
-SDCC Technical Data
-\layout Section
-Optimizations
-\begin_inset LatexCommand \index{Optimizations}
+\begin_inset LatexCommand \index{Endianness}
\end_inset
+ format (i.e.
+ lowest order first).
+\layout Subsection
-\layout Standard
+Highest Order Bit
+\begin_inset LatexCommand \index{Highest Order Bit}
-SDCC performs a host of standard optimizations in addition to some MCU specific
- optimizations.
-
-\layout Subsection
+\end_inset
-Sub-expression Elimination
-\begin_inset LatexCommand \index{Subexpression elimination}
+ / Any Order Bit
+\begin_inset LatexCommand \index{Any Order Bit}
\end_inset
\layout Standard
-The compiler does local and
-\emph on
-g
-\emph default
-lobal
-\emph on
-c
-\emph default
-ommon
-\emph on
-s
-\emph default
-ubexpression
-\emph on
-e
-\emph default
-limination, e.g.:
+It is frequently required to obtain the highest order bit of an integral
+ type (long, int, short or char types).
+ Also obtaining any other order bit is not uncommon.
+ SDCC recognizes the following expressions to yield the highest order bit
+ and generates optimized code for it, e.g.:
\layout Verse
\family typewriter
-i = x + y + 1;
+unsigned int gint;
+\newline
+
+\newline
+foo () {
+\newline
+\SpecialChar ~
+\SpecialChar ~
+unsigned char hob1, aob1;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+bit hob2, hob3, aob2, aob3;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+...
+
+\newline
+\SpecialChar ~
+\SpecialChar ~
+hob1 = (gint >> 15) & 1;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+hob2 = (gint >> 15) & 1;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+hob3 = gint & 0x8000;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+aob1 = (gint >> 9) & 1;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+aob2 = (gint >> 8) & 1;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+aob3 = gint & 0x0800;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+..
+
\newline
-j = x + y;
+}
\layout Standard
-will be translated to
+will generate the following code:
\layout Verse
\family typewriter
-iTemp = x + y;
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 61 ;\SpecialChar ~
+ hob.c 7
\newline
-i = iTemp + 1;
+000A E5*01\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 62\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ a,(_gint + 1)
\newline
-j = iTemp;
-\layout Standard
-
-Some subexpressions are not as obvious as the above example, e.g.:
-\layout Verse
-
-
-\family typewriter
-a->b[i].c = 10;
+000C 23\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 63\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ rl\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ a
\newline
-a->b[i].d = 11;
-\layout Standard
-
-In this case the address arithmetic a->b[i] will be computed only once;
- the equivalent code in C would be.
-\layout Verse
-
-
-\family typewriter
-iTemp = a->b[i];
+000D 54 01\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 64\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ anl\SpecialChar ~
+\SpecialChar ~
+ a,#0x01
\newline
-iTemp.c = 10;
+000F F5*02\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 65\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ _foo_hob1_1_1,a
\newline
-iTemp.d = 11;
-\layout Standard
-
-The compiler will try to keep these temporary variables in registers.
-\layout Subsection
-
-Dead-Code Elimination
-\begin_inset LatexCommand \index{Dead-code elimination}
-
-\end_inset
-
-
-\layout Verse
-
-
-\family typewriter
-int global;
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 66 ;\SpecialChar ~
+ hob.c 8
\newline
-
+0011 E5*01\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 67\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ a,(_gint + 1)
\newline
-void f () {
+0013 33\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 68\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ rlc\SpecialChar ~
+\SpecialChar ~
+ a
\newline
+0014 92*00\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-int i;
-\newline
\SpecialChar ~
\SpecialChar ~
-i = 1; \SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-/* dead store */
-\newline
\SpecialChar ~
\SpecialChar ~
-global = 1;\SpecialChar ~
-/* dead store */
-\newline
\SpecialChar ~
\SpecialChar ~
-global = 2;
-\newline
\SpecialChar ~
\SpecialChar ~
-return;
-\newline
+ 69\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-global = 3;\SpecialChar ~
-/* unreachable */
-\newline
-}
-\layout Standard
-
-will be changed to
-\layout Verse
-
-
-\family typewriter
-int global;
-\newline
-
-\newline
-void f () {
-\newline
\SpecialChar ~
\SpecialChar ~
-global = 2;
-\newline
\SpecialChar ~
\SpecialChar ~
-return;
-\newline
-}
-\layout Subsection
-
-Copy-Propagation
-\begin_inset LatexCommand \index{Copy propagation}
-
-\end_inset
-
-
-\layout Verse
-
-
-\family typewriter
-int f() {
-\newline
\SpecialChar ~
+ mov\SpecialChar ~
\SpecialChar ~
-int i, j;
+ _foo_hob2_1_1,c
\newline
\SpecialChar ~
\SpecialChar ~
-i = 10;
-\newline
\SpecialChar ~
\SpecialChar ~
-j = i;
-\newline
\SpecialChar ~
\SpecialChar ~
-return j;
-\newline
-}
-\layout Standard
-
-will be changed to
-\layout Verse
-
-
-\family typewriter
-int f() {
-\newline
\SpecialChar ~
\SpecialChar ~
-int i, j;
-\newline
\SpecialChar ~
\SpecialChar ~
-i = 10;
-\newline
\SpecialChar ~
\SpecialChar ~
-j = 10;
-\newline
\SpecialChar ~
\SpecialChar ~
-return 10;
-\newline
-}
-\layout Standard
-
-Note: the dead stores created by this copy propagation will be eliminated
- by dead-code elimination.
-\layout Subsection
-
-Loop Optimizations
-\begin_inset LatexCommand \index{Loop optimization}
-
-\end_inset
-
-
-\layout Standard
-
-Two types of loop optimizations are done by SDCC loop invariant lifting
- and strength reduction of loop induction variables.
- In addition to the strength reduction the optimizer marks the induction
- variables and the register allocator tries to keep the induction variables
- in registers for the duration of the loop.
- Because of this preference of the register allocator
-\begin_inset LatexCommand \index{Register allocation}
-
-\end_inset
-
-, loop induction optimization causes an increase in register pressure, which
- may cause unwanted spilling of other temporary variables into the stack
-\begin_inset LatexCommand \index{stack}
-
-\end_inset
-
- / data space.
- The compiler will generate a warning message when it is forced to allocate
- extra space either on the stack or data space.
- If this extra space allocation is undesirable then induction optimization
- can be eliminated either for the entire source file (with -
-\begin_inset ERT
-status Collapsed
-
-\layout Standard
-
-\backslash
-/
-\end_inset
-
--noinduction option) or for a given function only using #pragma\SpecialChar ~
-noinduction
-\begin_inset LatexCommand \index{\#pragma noinduction}
-
-\end_inset
-
-.
-\newline
-
-\newline
-Loop Invariant:
-\layout Verse
-
-
-\family typewriter
-for (i = 0 ; i < 100 ; i ++)
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-f += k + l;
-\layout Standard
-
-changed to
-\layout Verse
-
-
-\family typewriter
-itemp = k + l;
-\newline
-for (i = 0; i < 100; i++)
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-f += itemp;
-\layout Standard
-
-As mentioned previously some loop invariants are not as apparent, all static
- address computations are also moved out of the loop.
-\newline
-
-\newline
-Strength Reduction
-\begin_inset LatexCommand \index{Strength reduction}
-
-\end_inset
-
-, this optimization substitutes an expression by a cheaper expression:
-\layout Verse
-
-
-\family typewriter
-for (i=0;i < 100; i++)
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 66 ;\SpecialChar ~
+ hob.c 9
\newline
+0016 E5*01\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-ar[i*5] = i*3;
-\layout Standard
-
-changed to
-\layout Verse
-
-
-\family typewriter
-itemp1 = 0;
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 67\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ a,(_gint + 1)
\newline
-itemp2 = 0;
+0018 33\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 68\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ rlc\SpecialChar ~
+\SpecialChar ~
+ a
\newline
-for (i=0;i< 100;i++) {
+0019 92*01\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 69\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ _foo_hob3_1_1,c
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-ar[itemp1] = itemp2;
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-itemp1 += 5;
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-itemp2 += 3;
-\newline
-}
-\layout Standard
-
-The more expensive multiplication
-\begin_inset LatexCommand \index{Multiplication}
-
-\end_inset
-
- is changed to a less expensive addition.
-\layout Subsection
-
-Loop Reversing
-\begin_inset LatexCommand \index{Loop reversing}
-
-\end_inset
-
-
-\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
-\begin_inset Quotes eld
-\end_inset
-
-decrement and jump if not zero
-\begin_inset Quotes erd
-\end_inset
-
- instruction.
- SDCC checks for the following criterion to determine if a loop is reversible
- (note: more sophisticated compilers use data-dependency analysis to make
- this determination, SDCC uses a more simple minded analysis).
-\layout Itemize
-
-The 'for' loop is of the form
-\newline
-
-\newline
-
-\family typewriter
-for(<symbol> = <expression>; <sym> [< | <=] <expression>; [<sym>++ | <sym>
- += 1])
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-<for body>
-\layout Itemize
-
-The <for body> does not contain
-\begin_inset Quotes eld
-\end_inset
-
-continue
-\begin_inset Quotes erd
-\end_inset
-
- or 'break
-\begin_inset Quotes erd
-\end_inset
-
-.
-\layout Itemize
-
-All goto's are contained within the loop.
-\layout Itemize
-
-No function calls within the loop.
-\layout Itemize
-
-The loop control variable <sym> is not assigned any value within the loop
-\layout Itemize
-
-The loop control variable does NOT participate in any arithmetic operation
- within the loop.
-\layout Itemize
-
-There are NO switch statements in the loop.
-\layout Subsection
-
-Algebraic Simplifications
-\layout Standard
-
-SDCC does numerous algebraic simplifications, the following is a small sub-set
- of these optimizations.
-\layout Verse
-
-
-\family typewriter
-i = j + 0;\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- /* changed to: */\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- i = j;
-\newline
-i /= 2;\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 70 ;\SpecialChar ~
+ hob.c 10
+\newline
+001B E5*01\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- /* changed to: */\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- i >>= 1;
-\newline
-i = j - j;\SpecialChar ~
+ 71\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- /* changed to: */\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- i = 0;
-\newline
-i = j / 1;\SpecialChar ~
\SpecialChar ~
+ mov\SpecialChar ~
\SpecialChar ~
+ a,(_gint + 1)
+\newline
+001D 03\SpecialChar ~
\SpecialChar ~
- /* changed to: */\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- i = j;
-\layout Standard
-
-Note the subexpressions
-\begin_inset LatexCommand \index{Subexpression}
-
-\end_inset
-
- given above are generally introduced by macro expansions or as a result
- of copy/constant propagation.
-\layout Subsection
-
-'switch' Statements
-\begin_inset LatexCommand \label{sub:'switch'-Statements}
-
-\end_inset
-
-
-\begin_inset LatexCommand \index{switch statement}
-
-\end_inset
-
-
-\layout Standard
-
-SDCC changes switch statements to jump tables
-\begin_inset LatexCommand \index{jump tables}
-
-\end_inset
-
- when the following conditions are true.
-
-\layout Itemize
-
-The case labels are in numerical sequence, the labels need not be in order,
- and the starting number need not be one or zero.
-\begin_deeper
-\layout Verse
-
-
-\family typewriter
-switch(i) {\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 72\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ rr\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ a
+\newline
+001E 54 01\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-switch (i) {
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 4: ...\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 73\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ anl\SpecialChar ~
\SpecialChar ~
+ a,#0x01
+\newline
+0020 F5*03\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 0: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 5: ...\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 74\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ mov\SpecialChar ~
\SpecialChar ~
+ _foo_aob1_1_1,a
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 1: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 3: ...\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 75 ;\SpecialChar ~
+ hob.c 11
+\newline
+0022 E5*01\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 76\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 2: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 6: ...\SpecialChar ~
+ mov\SpecialChar ~
\SpecialChar ~
+ a,(_gint + 1)
+\newline
+0024 13\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 77\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 3: ...
-
+ rrc\SpecialChar ~
+\SpecialChar ~
+ a
\newline
-}\SpecialChar ~
+0025 92*02\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 78\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ mov\SpecialChar ~
\SpecialChar ~
+ _foo_aob2_1_1,c
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-}
-\layout Standard
-
-Both the above switch statements will be implemented using a jump-table.
- The example to the right side is slightly more efficient as the check for
- the lower boundary of the jump-table is not needed.
-\end_deeper
-\layout Itemize
-
-The number of case labels is at least three, since it takes two conditional
- statements to handle the boundary conditions.
-\layout Itemize
-
-The number of case labels is less than 84, since each label takes 3 bytes
- and a jump-table can be utmost 256 bytes long.
-\layout Standard
-
-Switch statements which have gaps in the numeric sequence or those that
- have more that 84 case labels can be split into more than one switch statement
- for efficient code generation, e.g.:
-\layout Verse
-
-
-\family typewriter
-switch (i) {
-\newline
\SpecialChar ~
\SpecialChar ~
-case 1: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 2: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 3: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 4: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 9: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 10: ...
-
+ 79 ;\SpecialChar ~
+ hob.c 12
\newline
+0027 E5*01\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 11: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 12: ...
-
-\newline
-}
-\layout Standard
-
-If the above switch statement is broken down into two switch statements
-\layout Verse
-
-
-\family typewriter
-switch (i) {
-\newline
\SpecialChar ~
\SpecialChar ~
-case 1: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 2: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 3: ...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 4: ...
-
-\newline
-}
-\layout Standard
-
-and
-\layout Verse
-
-
-\family typewriter
-switch (i) {
-\newline
\SpecialChar ~
\SpecialChar ~
-case 9:\SpecialChar ~
+ 80\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
\SpecialChar ~
-...
-
-\newline
\SpecialChar ~
\SpecialChar ~
-case 10:\SpecialChar ~
-...
-
-\newline
\SpecialChar ~
+ mov\SpecialChar ~
\SpecialChar ~
-case 11:\SpecialChar ~
-...
-
+ a,(_gint + 1)
\newline
+0029 A2 E3\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-case 12:\SpecialChar ~
-...
-
-\newline
-}
-\layout Standard
-
-then both the switch statements will be implemented using jump-tables whereas
- the unmodified switch statement will not be.
- You might also consider inserting dummy cases 0 and 5 to 8 in this example.
-
-\newline
-The pragma nojtbound
-\begin_inset LatexCommand \index{\#pragma nojtbound}
-
-\end_inset
-
- can be used to turn off checking the
-\emph on
-j
-\emph default
-ump
-\emph on
-t
-\emph default
-able
-\emph on
-bound
-\emph default
-aries.
- It has no effect if a default label is supplied.
- Use of this pragma is dangerous: if the switch argument is not matched
- by a case statement the processor will happily jump into Nirvana.
-\layout Subsection
-
-Bit-shifting Operations
-\begin_inset LatexCommand \index{Bit shifting}
-
-\end_inset
-
-.
-\layout Standard
-
-Bit shifting is one of the most frequently used operation in embedded programmin
-g.
- SDCC tries to implement bit-shift operations in the most efficient way
- possible, e.g.:
-\layout Verse
-
-
-\family typewriter
-unsigned char i;
-\newline
-...
-
-\newline
-i >>= 4;
-\newline
-...
-\layout Standard
-
-generates the following code:
-\layout Verse
-
-
-\family typewriter
-mov\SpecialChar ~
- a,_i
-\newline
-swap a
-\newline
-anl\SpecialChar ~
- a,#0x0f
-\newline
-mov\SpecialChar ~
- _i,a
-\layout Standard
-
-In general SDCC will never setup a loop if the shift count is known.
- Another example:
-\layout Verse
-
-
-\family typewriter
-unsigned int i;
-\newline
-...
-
-\newline
-i >>= 9;
-\newline
-...
-\layout Standard
-
-will generate:
-\layout Verse
-
-
-\family typewriter
-mov\SpecialChar ~
\SpecialChar ~
-a,(_i + 1)
-\newline
-mov\SpecialChar ~
\SpecialChar ~
-(_i + 1),#0x00
-\newline
-clr\SpecialChar ~
\SpecialChar ~
-c
-\newline
-rrc\SpecialChar ~
\SpecialChar ~
-a
-\newline
-mov\SpecialChar ~
\SpecialChar ~
-_i,a
-\layout Subsection
-
-Bit-rotation
-\begin_inset LatexCommand \index{Bit rotation}
-
-\end_inset
-
-
-\layout Standard
-
-A special case of the bit-shift operation is bit rotation
-\begin_inset LatexCommand \index{rotating bits}
-
-\end_inset
-
-, SDCC recognizes the following expression to be a left bit-rotation:
-\layout Verse
-
-
-\family typewriter
-\series bold
-unsigned
-\series default
\SpecialChar ~
\SpecialChar ~
-char i;\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 81\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
-/* unsigned is needed for rotation */
-\newline
-...
-
-\newline
-i = ((i << 1) | (i >> 7));
-\family default
-
-\newline
-
-\family typewriter
-...
-\layout Standard
-
-will generate the following code:
-\layout Verse
-
-
-\family typewriter
-mov\SpecialChar ~
\SpecialChar ~
-a,_i
-\newline
-rl\SpecialChar ~
\SpecialChar ~
+ mov\SpecialChar ~
\SpecialChar ~
-a
+ c,acc[3]
\newline
-mov\SpecialChar ~
+002B 92*03\SpecialChar ~
\SpecialChar ~
-_i,a
-\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.:
-\layout Verse
-
-
-\family typewriter
-i = ((i >> 7) | (i << 1)); /* left-bit rotation */
-\layout Subsection
-
-Nibble and Byte Swapping
-\layout Standard
-
-Other special cases of the bit-shift operations are nibble or byte swapping
-\begin_inset LatexCommand \index{swapping nibbles/bytes}
-
-\end_inset
-
-, SDCC recognizes the following expressions:
-\layout Verse
-
-
-\family typewriter
-\series bold
-unsigned
-\series default
\SpecialChar ~
\SpecialChar ~
-char i;
-\newline
-
-\series bold
-unsigned
-\series default
\SpecialChar ~
\SpecialChar ~
-int j;
-\newline
-...
-
-\newline
-i = ((i << 4) | (i >> 4));
-\family default
-
-\newline
-
-\family typewriter
-j = ((j << 8) | (j >> 8));
-\layout Standard
-
-and generates a swap instruction for the nibble swapping
-\begin_inset LatexCommand \index{Nibble swapping}
-
-\end_inset
-
- or move instructions for the byte swapping
-\begin_inset LatexCommand \index{Byte swapping}
-
-\end_inset
-
-.
- The
-\begin_inset Quotes sld
-\end_inset
-
-j
-\begin_inset Quotes srd
-\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
-\emph on
-signed
-\emph default
- integer you have to cast to
-\family typewriter
-(unsigned int)
-\family default
- first.
-\layout Standard
-
-Note that SDCC stores numbers in little-endian
-\begin_inset Foot
-collapsed false
-
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 82\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ _foo_aob3_1_1,c
\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
-\emph on
-dptr
-\emph default
-
-\begin_inset LatexCommand \index{DPTR}
-
-\end_inset
-
--datapointer
+Other variations of these cases however will
\emph on
-
+not
\emph default
-so little-endian is the more efficient byte order.
-\end_inset
-
+ be recognized.
+ They are standard C expressions, so I heartily recommend these be the only
+ way to get the highest order bit, (it is portable).
+ Of course it will be recognized even if it is embedded in other expressions,
+ e.g.:
+\layout Verse
-\begin_inset LatexCommand \index{little-endian}
-\end_inset
+\family typewriter
+xyz = gint + ((gint >> 15) & 1);
+\layout Standard
+will still be recognized.
+\layout Subsection
-\begin_inset LatexCommand \index{Endianness}
+Higher Order Byte
+\begin_inset LatexCommand \index{Higher Order Byte}
\end_inset
- format (i.e.
- lowest order first).
-\layout Subsection
-
-Highest Order Bit
-\begin_inset LatexCommand \index{Highest Order Bit}
+ / Higher Order Word
+\begin_inset LatexCommand \index{Higher Order Word}
\end_inset
\layout Standard
-It is frequently required to obtain the highest order bit of an integral
- type (long, int, short or char types).
- SDCC recognizes the following expression to yield the highest order bit
- and generates optimized code for it, e.g.:
+It is also frequently required to obtain a higher order byte or word of
+ a larger integral type (long, int or short types).
+ SDCC recognizes the following expressions to yield the higher order byte
+ or word and generates optimized code for it, e.g.:
\layout Verse
\family typewriter
unsigned int gint;
\newline
+unsigned long int glong;
+\newline
\newline
foo () {
\newline
\SpecialChar ~
\SpecialChar ~
-unsigned char hob;
+unsigned char hob1, hob2;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+unsigned int how1, how2;
\newline
\SpecialChar ~
\SpecialChar ~
\newline
\SpecialChar ~
\SpecialChar ~
-hob = (gint >> 15) & 1;
+hob1 = (gint >> 8) & 0xFF;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+hob2 = glong >> 24;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+how1 = (glong >> 16) & 0xFFFF;
+\newline
+\SpecialChar ~
+\SpecialChar ~
+how2 = glong >> 8;
\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- 61 ;\SpecialChar ~
- hob.c 7
+ 91 ;\SpecialChar ~
+ hob.c 15
\newline
-000A E5*01\SpecialChar ~
+0037 85*01*06\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+\SpecialChar ~
+ 92\SpecialChar ~
+\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- 62\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ mov\SpecialChar ~
\SpecialChar ~
+ _foo_hob1_1_1,(_gint + 1)
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- mov\SpecialChar ~
\SpecialChar ~
- a,(_gint + 1)
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 93 ;\SpecialChar ~
+ hob.c 16
\newline
-000C 23\SpecialChar ~
+003A 85*05*07\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ 94\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- 63\SpecialChar ~
\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ _foo_hob2_1_1,(_glong + 3)
+\newline
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- rl\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- a
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 95 ;\SpecialChar ~
+ hob.c 17
\newline
-000D 54 01\SpecialChar ~
+003D 85*04*08\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+\SpecialChar ~
+ 96\SpecialChar ~
+\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- 64\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+ mov\SpecialChar ~
\SpecialChar ~
+ _foo_how1_1_1,(_glong + 2)
+\newline
+0040 85*05*09\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- anl\SpecialChar ~
\SpecialChar ~
- a,#0x01
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 97\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ (_foo_how1_1_1 + 1),(_glong + 3)
\newline
-000F F5*02\SpecialChar ~
+0043 85*03*0A\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
+\SpecialChar ~
+ 98\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ mov\SpecialChar ~
+\SpecialChar ~
+ _foo_how2_1_1,(_glong + 1)
+\newline
+0046 85*04*0B\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
- 65\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+\SpecialChar ~
+ 99\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
\SpecialChar ~
mov\SpecialChar ~
\SpecialChar ~
- _foo_hob_1_1,a
+ (_foo_how2_1_1 + 1),(_glong + 2)
\layout Standard
-Variations of this case however will
+Again, variations of these cases may
\emph on
not
\emph default
be recognized.
- It is a standard C expression, so I heartily recommend this be the only
- way to get the highest order bit, (it is portable).
+ They are standard C expressions, so I heartily recommend these be the only
+ way to get the higher order byte/word, (it is portable).
Of course it will be recognized even if it is embedded in other expressions,
e.g.:
\layout Verse
\family typewriter
-xyz = gint + ((gint >> 15) & 1);
+xyz = gint + ((gint >> 8) & 0xFF);
\layout Standard
will still be recognized.
copt
\emph default
a peep-hole optimizer by Christopher W.
- Fraser (cwfraser@microsoft.com).
+ Fraser (cwfraser\SpecialChar ~
+@\SpecialChar ~
+microsoft.com).
A default set of rules are compiled into the compiler, additional rules
may be added with the
\emph on
\emph default
).
E.g.
- some variants of the 8051 MCU allow only
+ some variants of the 8051 MCU
+\begin_inset LatexCommand \index{MCS51 variants}
+
+\end_inset
+
+ allow only
\family typewriter
ajmp
\family default
Deviations from the compliance:
\layout Itemize
-functions are not always reentrant
+functions are not reentrant
\begin_inset LatexCommand \index{reentrant}
\end_inset
-.
+ unless explicitly declared as such or the
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-stack-auto
+\begin_inset LatexCommand \index{-\/-stack-auto}
+
+\end_inset
+
+
+\series default
+ command line option is specified.
\layout Itemize
-structures cannot be assigned values directly, cannot be passed as function
- parameters or assigned to each other and cannot be a return value from
- a function, e.g.:
+structures and unions cannot be assigned values directly, cannot be passed
+ as function parameters or assigned to each other and cannot be a return
+ value from a function, e.g.:
\begin_deeper
\layout Verse
\end_deeper
\layout Itemize
+initialization of structure arrays must be fully braced.
+\begin_deeper
+\layout Verse
+
+
+\family typewriter
+struct s { char x } a[] = {1, 2}; /* invalid in SDCC */
+\newline
+struct s { char x } a[] = {{1}, {2}}; /* OK */
+\end_deeper
+\layout Itemize
+
'long long
\begin_inset LatexCommand \index{long long (not supported)}
not supported.
\layout Itemize
-No support for setjmp
-\begin_inset LatexCommand \index{setjmp (not supported)}
-
-\end_inset
-
- and longjmp
-\begin_inset LatexCommand \index{longjmp (not supported)}
-
-\end_inset
-
- (for now).
-\layout Itemize
-
Old K&R style
\begin_inset LatexCommand \index{K\&R style}
\end_deeper
\layout Itemize
-functions declared as pointers
-\begin_inset LatexCommand \index{Pointer (to function)}
+Most enhancements in C99 are not supported, f.e.:
+\begin_deeper
+\layout Verse
+
+
+\family typewriter
+\series bold
+inline
+\series default
+ int increment (int a) { return a+1; } /* is invalid in SDCC although allowed
+ in C99 */
+\newline
+for (
+\series bold
+int
+\series default
+ i=0; i<10; i++) /* is invalid in SDCC although allowed in C99 */
+\end_deeper
+\layout Itemize
+
+Certain words that are valid identifiers in the standard may be reserved
+ words in SDCC unless the
+\series bold
+-
+\begin_inset ERT
+status Collapsed
+
+\layout Standard
+
+\backslash
+/
+\end_inset
+
+-std-c89
+\begin_inset LatexCommand \index{-\/-std-c89}
\end_inset
+ or -
+\begin_inset ERT
+status Collapsed
-\begin_inset LatexCommand \index{function pointers}
+\layout Standard
+\backslash
+/
\end_inset
- must be dereferenced during the call.
-\begin_deeper
-\layout Verse
+-std-c99
+\begin_inset LatexCommand \index{-\/-std-c99}
+\end_inset
-\family typewriter
-int (*foo)();
-\newline
-...
-
-\newline
-/* has to be called like this */
-\newline
-(*foo)(); /* ANSI standard allows calls to be made like 'foo()' */
-\end_deeper
+
+\series default
+ command line options are used.
+ These may include (depending on the selected processor): 'at', 'banked',
+ 'bit', 'code', 'critical', 'data', 'eeprom', 'far', 'flash', 'idata', 'interrup
+t', 'near', 'nonbanked', 'pdata', 'reentrant', 'sbit', 'sfr', 'shadowregs',
+ 'sram', 'using', 'wparam', 'xdata', '_overlay', '_asm', '_endasm', and
+ '_naked'.
+ Compliant equivalents of these keywords are always available in a form
+ that begin with two underscores
+\begin_inset LatexCommand \index{\_\_ (prefix for extended keywords)}
+
+\end_inset
+
+, f.e.
+ '__data' instead of 'data'.
\layout Section
Cyclomatic Complexity
\shape italic
This is an excerpt from an article published in Circuit Cellar Magazine
- in august 2000.
+ in
+\series bold
+August 2000
+\series default
+.
It's a little outdated (the compiler is much more efficient now and user/develo
per friendly), but pretty well exposes the guts of it all.
\shape default
\series bold
\shape italic
\color red
-<Where is Figure II ?>
+<Where is Figure II?>
+\layout Comment
+
+In the original article Figure II was announced to be downloadable on
+\shape italic
+Circuit Cellar
+\shape default
+'s web site.
+ Unfortunately it never seemed to have shown up there, so: where is Figure
+ II?
\layout Paragraph*
ICode Example
projects / fw / sdcc / blobdiff