\size normal
-SDCC 2.5.5
+SDCC 2.5.6
\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
\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
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
\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:
\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
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 CVS repository it's easiest to configure the cvs client
- to convert automatically for you.
+ 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.
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.
.
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
\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
\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
\series default
- Disable peep-hole optimization.
+ Disable peep-hole optimization with built-in rules.
\layout List
\labelwidthstring 00.00.0000
\end_inset
).
+ This is the
+\series bold
+default
+\series default
+ storage class for the Medium Memory model, e.g.:
\layout Verse
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
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.
+By default, SDCC generates code for a maskable interrupt, which uses a RETI
+ instruction to return from the interrupt.
To write an interrupt handler for the non-maskable interrupt, which needs
- an RETN instruction instead, add the
+ a RETN instruction instead, add the
\emph on
critical
\emph default
\newline
}
+\layout Standard
+
+However if you need to create a non-interruptable interrupt service routine
+ you would also require the
+\emph on
+critical
+\emph default
+ keyword.
+ To distinguish between this and an nmi_isr you must provide an interrupt
+ number.
\layout Section
Enabling and Disabling Interrupts
\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
\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">
<column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
\layout Standard
-this Symbol is always defined
+this Symbol is always defined.
+ Since version 2.5.6 it's this version number as an int (ex.
+ 256)
\end_inset
</cell>
</row>
\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}
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.
+ Sdcdb is currently not available on Win32 platforms.
\layout Section
Compiling for Debugging
The .eps File
\size footnotesize
-\begin_inset LatexCommand \url{http://cvs.sourceforge.net/viewcvs.py/*checkout*/sdcc/sdcc/doc/figures/ddd_example.eps}
+\begin_inset LatexCommand \url{http://svn.sourceforge.net/viewcvs.cgi/*checkout*/sdcc/trunk/sdcc/doc/figures/ddd_example.eps}
\end_inset
\end_inset
- area and cvs code repository
-\begin_inset LatexCommand \index{cvs code repository}
+ area and Subversion code repository
+\begin_inset LatexCommand \index{Subversion code repository}
\end_inset
ChangeLog
\layout Standard
-You can follow the status of the cvs version
+You can follow the status of the Subversion version
\begin_inset LatexCommand \index{version}
\end_inset
\end_inset
- in the cvs-repository
+ in the Subversion repository
\newline
\size footnotesize
-\begin_inset LatexCommand \htmlurl{http://cvs.sf.net/cgi-bin/viewcvs.cgi/*checkout*/sdcc/sdcc/ChangeLog?rev=HEAD&content-type=text/plain}
+\begin_inset LatexCommand \htmlurl{http://svn.sourceforge.net/viewcvs.cgi/*checkout*/sdcc/trunk/sdcc/ChangeLog}
\end_inset
sdcc/src/regression
\shape default
.
+\layout Section
+
+Use of SDCC in Education
+\layout Standard
+
+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
+
+.
+ If your rationales are to:
+\layout Enumerate
+
+give students a chance to understand the
+\emph on
+complete
+\emph default
+ steps of code generation
+\layout Enumerate
+
+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}
+
+\end_inset
+
+,
+\begin_inset LatexCommand \url[Oregano]{http://www.oregano.at/ip/ip01.htm}
+
+\end_inset
+
+), 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
+
+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}
+
+\end_inset
+
+, 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
+
+.
+
+\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}
+
+\end_inset
+
+.
+\layout Enumerate
+
+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
+
+not encourage students to use illegal copies of educational software
+\layout Enumerate
+
+be immune to licensing/availability/price changes of the chosen tool chain
+\layout Enumerate
+
+be able to change to a new target platform without having to adopt a new
+ tool chain
+\layout Enumerate
+
+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
+
+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
+
+then SDCC is probably among the first choices.
+ Well, probably SDCC might be the only choice.
\layout Chapter
\pagebreak_top
SDCC Technical Data
\emph default
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).
+ 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
\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
+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