1 #LyX 1.3 created this file. For more info see http://www.lyx.org/
5 \pdfoptionpdfminorversion=3
7 pdftitle={SDCC Compiler User Guide},
8 pdfauthor={SDCC development team},
9 pdfsubject={installation, user manual},
10 pdfkeywords={8032 8051 ansi c compiler CPU DS390
11 embedded GPL HC08 manual mcs51 microcontroller PIC Z80},
13 linkcolor=blue] {hyperref}
17 \emergencystretch=30pt
22 \inputencoding default
25 \paperfontsize default
27 \papersize letterpaper
32 \use_numerical_citations 0
33 \paperorientation portrait
40 \paragraph_separation indent
42 \quotes_language swedish
50 Please note: double dashed longoptions (e.g.
51 --version) are written this way: -
65 three consecutive dashes simply result in a long resp.
69 Architecture specific stuff (like memory models, code examples) should maybe
73 into seperate sections/chapters/appendices (it is hard to document PIC or
77 a 8051 centered document) - for now simply add.
80 SDCC Compiler User Guide
94 The above strings enclosed in $ are automatically updated by cvs
98 \begin_inset LatexCommand \tableofcontents{}
131 ompiler) is an open source, retargettable, optimizing ANSI-C compiler by
136 designed for 8 bit Microprocessors.
137 The current version targets Intel MCS51 based Microprocessors (8031, 8032,
139 \begin_inset LatexCommand \index{8031, 8032, 8051, 8052, mcs51 CPU}
143 , etc.), Dallas DS80C390 variants, Freescale (formerly Motorola) HC08 and
144 Zilog Z80 based MCUs.
145 It can be retargetted for other microprocessors, support for Microchip
146 PIC, Atmel AVR is under development.
147 The entire source code for the compiler is distributed under GPL.
149 \begin_inset LatexCommand \index{asXXXX (as-gbz80, as-hc08, asx8051, as-z80)}
154 \begin_inset LatexCommand \index{aslink}
158 , an open source retargettable assembler & linker.
159 SDCC has extensive language extensions suitable for utilizing various microcont
160 rollers and underlying hardware effectively.
165 In addition to the MCU specific optimizations SDCC also does a host of standard
169 global sub expression elimination,
172 loop optimizations (loop invariant, strength reduction of induction variables
176 constant folding & propagation,
182 dead code elimination
192 For the back-end SDCC uses a global register allocation scheme which should
193 be well suited for other 8 bit MCUs.
198 The peep hole optimizer uses a rule based substitution mechanism which is
204 Supported data-types are:
207 char (8 bits, 1 byte),
210 short and int (16 bits, 2 bytes),
213 long (32 bit, 4 bytes)
220 The compiler also allows
222 inline assembler code
224 to be embedded anywhere in a function.
225 In addition, routines developed in assembly can also be called.
229 SDCC also provides an option (-
239 -cyclomatic) to report the relative complexity of a function.
240 These functions can then be further optimized, or hand coded in assembly
246 SDCC also comes with a companion source level debugger SDCDB, the debugger
247 currently uses ucSim a freeware simulator for 8051 and other micro-controllers.
252 The latest version can be downloaded from
253 \begin_inset LatexCommand \url{http://sdcc.sourceforge.net/snap.php}
263 Please note: the compiler will probably always be some steps ahead of this
268 \begin_inset LatexCommand \index{Status of documentation}
278 Obviously this has pros and cons
287 All packages used in this compiler system are
295 ; source code for all the sub-packages (pre-processor, assemblers, linkers
296 etc) is distributed with the package.
297 This documentation is maintained using a freeware word processor (LyX).
299 This program is free software; you can redistribute it and/or modify it
300 under the terms of the GNU General Public License
301 \begin_inset LatexCommand \index{GNU General Public License, GPL}
305 as published by the Free Software Foundation; either version 2, or (at
306 your option) any later version.
307 This program is distributed in the hope that it will be useful, but WITHOUT
308 ANY WARRANTY; without even the implied warranty
309 \begin_inset LatexCommand \index{warranty}
313 of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
314 See the GNU General Public License for more details.
315 You should have received a copy of the GNU General Public License along
316 with this program; if not, write to the Free Software Foundation, 59 Temple
317 Place - Suite 330, Boston, MA 02111-1307, USA.
318 In other words, you are welcome to use, share and improve this program.
319 You are forbidden to forbid anyone else to use, share and improve what
321 Help stamp out software-hoarding!
324 Typographic conventions
325 \begin_inset LatexCommand \index{Typographic conventions}
332 Throughout this manual, we will use the following convention.
333 Commands you have to type in are printed in
341 Code samples are printed in
346 Interesting items and new terms are printed in
351 Compatibility with previous versions
352 \begin_inset LatexCommand \index{Compatibility with previous versions}
359 This version has numerous bug fixes compared with the previous version.
360 But we also introduced some incompatibilities with older versions.
361 Not just for the fun of it, but to make the compiler more stable, efficient
363 \begin_inset LatexCommand \index{ANSI-compliance}
368 \begin_inset LatexCommand \ref{sub:ANSI-Compliance}
372 for ANSI-Compliance).
378 short is now equivalent to int (16 bits), it used to be equivalent to char
379 (8 bits) which is not ANSI compliant.
382 the default directory for gcc-builds where include, library and documentation
383 files are stored is now in /usr/local/share.
386 char type parameters to vararg functions are casted to int unless explicitly
403 will push a as an int and as a char resp.
416 -regextend has been removed.
429 -noregparms has been removed.
442 -stack-after-data has been removed.
446 \begin_inset LatexCommand \index{bit}
451 \begin_inset LatexCommand \index{sbit}
456 \begin_inset LatexCommand \index{\_\_sbit}
460 types now consistently behave like the C99 _Bool type with respect to type
462 \begin_inset LatexCommand \index{type conversion}
467 \begin_inset LatexCommand \index{type promotion}
472 The most common incompatibility resulting from this change is related to
474 \begin_inset LatexCommand \index{Bit toggling}
488 b = ~b; /* equivalent to b=1 instead of toggling b */
492 b = !b; /* toggles b */
496 In previous versions, both forms would have toggled the bit.
501 <pending: more incompatibilities?>
507 What do you need before you start installation of SDCC? A computer, and
509 The preferred method of installation is to compile SDCC from source using
511 For Windows some pre-compiled binary distributions are available for your
513 You should have some experience with command line tools and compiler use.
519 The SDCC home page at
520 \begin_inset LatexCommand \url{http://sdcc.sourceforge.net/}
524 is a great place to find distribution sets.
525 You can also find links to the user mailing lists that offer help or discuss
526 SDCC with other SDCC users.
527 Web links to other SDCC related sites can also be found here.
528 This document can be found in the DOC directory of the source package as
530 A pdf version of this document is available at
531 \begin_inset LatexCommand \url{http://sdcc.sourceforge.net/doc/sdccman.pdf}
536 Some of the other tools (simulator and assembler) included with SDCC contain
537 their own documentation and can be found in the source distribution.
538 If you want the latest unreleased software, the complete source package
539 is available directly by anonymous CVS on cvs.sdcc.sourceforge.net.
542 Wishes for the future
545 There are (and always will be) some things that could be done.
546 Here are some I can think of:
553 char KernelFunction3(char p) at 0x340;
561 \begin_inset LatexCommand \index{code banking (not supported)}
571 If you can think of some more, please see the section
572 \begin_inset LatexCommand \ref{sub:Requesting-Features}
576 about filing feature requests
577 \begin_inset LatexCommand \index{Requesting features}
582 \begin_inset LatexCommand \index{Feature request}
592 \begin_inset LatexCommand \index{Installation}
599 For most users it is sufficient to skip to either section
600 \begin_inset LatexCommand \ref{sub:Building-SDCC-on-Linux}
605 \begin_inset LatexCommand \ref{sub:Windows-Install}
610 More detailled instructions follow below.
614 \begin_inset LatexCommand \index{Options SDCC configuration}
621 The install paths, search paths and other options are defined when running
623 The defaults can be overridden by:
625 \labelwidthstring 00.00.0000
637 -prefix see table below
639 \labelwidthstring 00.00.0000
651 -exec_prefix see table below
653 \labelwidthstring 00.00.0000
665 -bindir see table below
667 \labelwidthstring 00.00.0000
679 -datadir see table below
681 \labelwidthstring 00.00.0000
683 docdir environment variable, see table below
685 \labelwidthstring 00.00.0000
687 include_dir_suffix environment variable, see table below
689 \labelwidthstring 00.00.0000
691 lib_dir_suffix environment variable, see table below
693 \labelwidthstring 00.00.0000
695 sdccconf_h_dir_separator environment variable, either / or
700 This character will only be used in sdccconf.h; don't forget it's a C-header,
701 therefore a double-backslash is needed there.
703 \labelwidthstring 00.00.0000
715 -disable-mcs51-port Excludes the Intel mcs51 port
717 \labelwidthstring 00.00.0000
729 -disable-gbz80-port Excludes the Gameboy gbz80 port
731 \labelwidthstring 00.00.0000
743 -disable-z80-port Excludes the z80 port
745 \labelwidthstring 00.00.0000
757 -disable-avr-port Excludes the AVR port
759 \labelwidthstring 00.00.0000
771 -disable-ds390-port Excludes the DS390 port
773 \labelwidthstring 00.00.0000
785 -disable-hc08-port Excludes the HC08 port
787 \labelwidthstring 00.00.0000
799 -disable-pic-port Excludes the PIC port
801 \labelwidthstring 00.00.0000
813 -disable-xa51-port Excludes the XA51 port
815 \labelwidthstring 00.00.0000
827 -disable-ucsim Disables configuring and building of ucsim
829 \labelwidthstring 00.00.0000
841 -disable-device-lib-build Disables automatically building device libraries
843 \labelwidthstring 00.00.0000
855 -disable-packihx Disables building packihx
857 \labelwidthstring 00.00.0000
869 -enable-libgc Use the Bohem memory allocator.
870 Lower runtime footprint.
873 Furthermore the environment variables CC, CFLAGS, ...
874 the tools and their arguments can be influenced.
875 Please see `configure -
885 -help` and the man/info pages of `configure` for details.
889 The names of the standard libraries STD_LIB, STD_INT_LIB, STD_LONG_LIB,
890 STD_FP_LIB, STD_DS390_LIB, STD_XA51_LIB and the environment variables SDCC_DIR_
891 NAME, SDCC_INCLUDE_NAME, SDCC_LIB_NAME are defined by `configure` too.
892 At the moment it's not possible to change the default settings (it was
893 simply never required).
897 These configure options are compiled into the binaries, and can only be
898 changed by rerunning 'configure' and recompiling SDCC.
899 The configure options are written in
903 to distinguish them from run time environment variables (see section search
909 \begin_inset Quotes sld
913 \begin_inset Quotes srd
916 are used by the SDCC team to build the official Win32 binaries.
917 The SDCC team uses Mingw32 to build the official Windows binaries, because
924 a gcc compiler and last but not least
927 the binaries can be built by cross compiling on Sourceforge's compile farm.
930 See the examples, how to pass the Win32 settings to 'configure'.
931 The other Win32 builds using Borland, VC or whatever don't use 'configure',
932 but a header file sdcc_vc_in.h is the same as sdccconf.h built by 'configure'
944 <lyxtabular version="3" rows="8" columns="3">
946 <column alignment="block" valignment="top" leftline="true" width="0in">
947 <column alignment="block" valignment="top" leftline="true" width="0in">
948 <column alignment="block" valignment="top" leftline="true" rightline="true" width="0in">
949 <row topline="true" bottomline="true">
950 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
958 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
966 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
976 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
986 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
994 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1005 <row topline="true">
1006 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1016 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1026 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1037 <row topline="true">
1038 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1048 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1060 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1075 <row topline="true">
1076 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1086 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1098 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1109 <row topline="true">
1110 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1120 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1132 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1147 <row topline="true">
1148 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1158 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1166 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1175 <row topline="true" bottomline="true">
1176 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1186 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1194 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1212 'configure' also computes relative paths.
1213 This is needed for full relocatability of a binary package and to complete
1214 search paths (see section search paths below):
1220 \begin_inset Tabular
1221 <lyxtabular version="3" rows="4" columns="3">
1223 <column alignment="block" valignment="top" leftline="true" width="0in">
1224 <column alignment="block" valignment="top" leftline="true" width="0in">
1225 <column alignment="block" valignment="top" leftline="true" rightline="true" width="0in">
1226 <row topline="true" bottomline="true">
1227 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1235 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1243 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1252 <row topline="true" bottomline="true">
1253 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1263 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1271 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1280 <row bottomline="true">
1281 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1291 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1299 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1308 <row bottomline="true">
1309 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1319 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1327 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1360 \begin_inset Quotes srd
1364 \begin_inset Quotes srd
1378 \begin_inset Quotes srd
1382 \begin_inset Quotes srd
1410 To cross compile on linux for Mingw32 (see also 'sdcc/support/scripts/sdcc_mingw
1419 \begin_inset Quotes srd
1422 i586-mingw32msvc-gcc
1423 \begin_inset Quotes srd
1427 \begin_inset Quotes srd
1430 i586-mingw32msvc-g++
1431 \begin_inset Quotes srd
1439 \begin_inset Quotes srd
1442 i586-mingw32msvc-ranlib
1443 \begin_inset Quotes srd
1451 \begin_inset Quotes srd
1454 i586-mingw32msvc-strip
1455 \begin_inset Quotes srd
1473 \begin_inset Quotes srd
1477 \begin_inset Quotes srd
1495 \begin_inset Quotes srd
1499 \begin_inset Quotes srd
1507 \begin_inset Quotes srd
1511 \begin_inset Quotes srd
1519 \begin_inset Quotes srd
1523 \begin_inset Quotes srd
1531 \begin_inset Quotes srd
1535 \begin_inset Quotes srd
1542 sdccconf_h_dir_separator=
1543 \begin_inset Quotes srd
1555 \begin_inset Quotes srd
1572 -disable-device-lib-build
1600 -host=i586-mingw32msvc -
1610 -build=unknown-unknown-linux-gnu
1614 \begin_inset Quotes sld
1618 \begin_inset Quotes srd
1621 compile on Cygwin for Mingw32 (see also sdcc/support/scripts/sdcc_cygwin_mingw32
1630 \begin_inset Quotes srd
1634 \begin_inset Quotes srd
1642 \begin_inset Quotes srd
1646 \begin_inset Quotes srd
1664 \begin_inset Quotes srd
1668 \begin_inset Quotes srd
1686 \begin_inset Quotes srd
1690 \begin_inset Quotes srd
1698 \begin_inset Quotes srd
1702 \begin_inset Quotes srd
1710 \begin_inset Quotes srd
1714 \begin_inset Quotes srd
1722 \begin_inset Quotes srd
1726 \begin_inset Quotes srd
1733 sdccconf_h_dir_separator=
1734 \begin_inset Quotes srd
1746 \begin_inset Quotes srd
1766 'configure' is quite slow on Cygwin (at least on windows before Win2000/XP).
1777 -C' turns on caching, which gives a little bit extra speed.
1778 However if options are changed, it can be necessary to delete the config.cache
1783 \begin_inset LatexCommand \label{sub:Install-paths}
1788 \begin_inset LatexCommand \index{Install paths}
1794 \added_space_top medskip \align center
1796 \begin_inset Tabular
1797 <lyxtabular version="3" rows="5" columns="4">
1799 <column alignment="center" valignment="top" leftline="true" width="0">
1800 <column alignment="center" valignment="top" leftline="true" width="0">
1801 <column alignment="center" valignment="top" leftline="true" width="0">
1802 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
1803 <row topline="true" bottomline="true">
1804 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1814 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1824 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1834 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1845 <row topline="true">
1846 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1854 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1864 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1872 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1885 <row topline="true">
1886 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1894 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1901 $DATADIR/ $INCLUDE_DIR_SUFFIX
1904 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1909 /usr/local/share/sdcc/include
1912 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1925 <row topline="true">
1926 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1934 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1941 $DATADIR/$LIB_DIR_SUFFIX
1944 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1949 /usr/local/share/sdcc/lib
1952 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1965 <row topline="true" bottomline="true">
1966 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1974 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1984 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1989 /usr/local/share/sdcc/doc
1992 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2014 *compiler, preprocessor, assembler, and linker
2020 is auto-appended by the compiler, e.g.
2021 small, large, z80, ds390 etc
2024 The install paths can still be changed during `make install` with e.g.:
2027 make install prefix=$(HOME)/local/sdcc
2030 Of course this doesn't change the search paths compiled into the binaries.
2034 Moreover the install path can be changed by defining DESTDIR
2035 \begin_inset LatexCommand \index{DESTDIR}
2042 make install DESTDIR=$(HOME)/sdcc.rpm/
2045 Please note that DESTDIR must have a trailing slash!
2049 \begin_inset LatexCommand \label{sub:Search-Paths}
2054 \begin_inset LatexCommand \index{Search path}
2061 Some search paths or parts of them are determined by configure variables
2066 , see section above).
2067 Further search paths are determined by environment variables during runtime.
2070 The paths searched when running the compiler are as follows (the first catch
2076 Binary files (preprocessor, assembler and linker)
2082 \begin_inset Tabular
2083 <lyxtabular version="3" rows="4" columns="3">
2085 <column alignment="block" valignment="top" leftline="true" width="0in">
2086 <column alignment="block" valignment="top" leftline="true" width="0in">
2087 <column alignment="block" valignment="top" leftline="true" rightline="true" width="0in">
2088 <row topline="true" bottomline="true">
2089 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2097 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2105 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2114 <row topline="true">
2115 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2125 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2133 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2144 <row topline="true">
2145 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2150 Path of argv[0] (if available)
2153 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2161 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2170 <row topline="true" bottomline="true">
2171 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2179 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2187 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2212 \begin_inset Tabular
2213 <lyxtabular version="3" rows="6" columns="3">
2215 <column alignment="block" valignment="top" leftline="true" width="1.5in">
2216 <column alignment="block" valignment="top" leftline="true" width="1.5in">
2217 <column alignment="block" valignment="top" leftline="true" rightline="true" width="0in">
2218 <row topline="true" bottomline="true">
2219 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2227 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2235 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2244 <row topline="true">
2245 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2263 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2281 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2300 <row topline="true">
2301 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2309 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2317 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2326 <row topline="true">
2327 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2341 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2353 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2364 <row topline="true">
2365 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2383 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2433 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2446 <row topline="true" bottomline="true">
2447 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2463 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2468 /usr/local/share/sdcc/
2473 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2501 -nostdinc disables the last two search paths.
2511 With the exception of
2512 \begin_inset Quotes sld
2526 \begin_inset Quotes srd
2533 is auto-appended by the compiler (e.g.
2534 small, large, z80, ds390 etc.).
2541 \begin_inset Tabular
2542 <lyxtabular version="3" rows="6" columns="3">
2544 <column alignment="block" valignment="top" leftline="true" width="1.7in">
2545 <column alignment="block" valignment="top" leftline="true" width="1.2in">
2546 <column alignment="block" valignment="top" leftline="true" rightline="true" width="1.2in">
2547 <row topline="true" bottomline="true">
2548 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2556 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2564 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2573 <row topline="true">
2574 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2592 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2610 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2629 <row topline="true">
2630 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2642 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2654 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2669 <row topline="true">
2670 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2681 $LIB_DIR_SUFFIX/<model>
2684 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2698 <cell alignment="left" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2715 <row topline="true">
2716 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2731 $LIB_DIR_SUFFIX/<model>
2734 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2787 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2843 <row topline="true" bottomline="true">
2844 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2853 $LIB_DIR_SUFFIX/<model>
2856 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2861 /usr/local/share/sdcc/
2868 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2886 Don't delete any of the stray spaces in the table above without checking
2887 the HTML output (last line)!
2903 -nostdlib disables the last two search paths.
2907 \begin_inset LatexCommand \index{Building SDCC}
2914 Building SDCC on Linux
2915 \begin_inset LatexCommand \label{sub:Building-SDCC-on-Linux}
2924 Download the source package
2926 either from the SDCC CVS repository or from the nightly snapshots
2928 , it will be named something like sdcc
2939 \begin_inset LatexCommand \url{http://sdcc.sourceforge.net/snap.php}
2948 Bring up a command line terminal, such as xterm.
2953 Unpack the file using a command like:
2956 "tar -xvzf sdcc.src.tar.gz
2961 , this will create a sub-directory called sdcc with all of the sources.
2964 Change directory into the main SDCC directory, for example type:
2981 This configures the package for compilation on your system.
2997 All of the source packages will compile, this can take a while.
3013 This copies the binary executables, the include files, the libraries and
3014 the documentation to the install directories.
3015 Proceed with section
3016 \begin_inset LatexCommand \ref{sec:Testing-the-SDCC}
3023 Building SDCC on OSX 2.x
3026 Follow the instruction for Linux.
3030 On OSX 2.x it was reported, that the default gcc (version 3.1 20020420 (prerelease
3031 )) fails to compile SDCC.
3032 Fortunately there's also gcc 2.9.x installed, which works fine.
3033 This compiler can be selected by running 'configure' with:
3036 ./configure CC=gcc2 CXX=g++2
3039 Cross compiling SDCC on Linux for Windows
3042 With the Mingw32 gcc cross compiler it's easy to compile SDCC for Win32.
3043 See section 'Configure Options'.
3046 Building SDCC on Windows
3049 With the exception of Cygwin the SDCC binaries uCsim and sdcdb can't be
3051 They use Unix-sockets, which are not available on Win32.
3054 Building SDCC using Cygwin and Mingw32
3057 For building and installing a Cygwin executable follow the instructions
3063 \begin_inset Quotes sld
3067 \begin_inset Quotes srd
3070 Win32-binary can be built, which will not need the Cygwin-DLL.
3071 For the necessary 'configure' options see section 'configure options' or
3072 the script 'sdcc/support/scripts/sdcc_cygwin_mingw32'.
3076 In order to install Cygwin on Windows download setup.exe from
3077 \begin_inset LatexCommand \url[www.cygwin.com]{http://www.cygwin.com/}
3083 \begin_inset Quotes sld
3086 default text file type
3087 \begin_inset Quotes srd
3091 \begin_inset Quotes sld
3095 \begin_inset Quotes srd
3098 and download/install at least the following packages.
3099 Some packages are selected by default, others will be automatically selected
3100 because of dependencies with the manually selected packages.
3101 Never deselect these packages!
3110 gcc ; version 3.x is fine, no need to use the old 2.9x
3113 binutils ; selected with gcc
3119 rxvt ; a nice console, which makes life much easier under windoze (see below)
3122 man ; not really needed for building SDCC, but you'll miss it sooner or
3126 less ; not really needed for building SDCC, but you'll miss it sooner or
3130 cvs ; only if you use CVS access
3133 If you want to develop something you'll need:
3136 python ; for the regression tests
3139 gdb ; the gnu debugger, together with the nice GUI
3140 \begin_inset Quotes sld
3144 \begin_inset Quotes srd
3150 openssh ; to access the CF or commit changes
3153 autoconf and autoconf-devel ; if you want to fight with 'configure', don't
3154 use autoconf-stable!
3157 rxvt is a nice console with history.
3158 Replace in your cygwin.bat the line
3177 rxvt -sl 1000 -fn "Lucida Console-12" -sr -cr red
3180 -bg black -fg white -geometry 100x65 -e bash -
3193 Text selected with the mouse is automatically copied to the clipboard, pasting
3194 works with shift-insert.
3198 The other good tip is to make sure you have no //c/-style paths anywhere,
3199 use /cygdrive/c/ instead.
3200 Using // invokes a network lookup which is very slow.
3202 \begin_inset Quotes sld
3206 \begin_inset Quotes srd
3209 is too long, you can change it with e.g.
3215 SDCC sources use the unix line ending LF.
3216 Life is much easier, if you store the source tree on a drive which is mounted
3218 And use an editor which can handle LF-only line endings.
3219 Make sure not to commit files with windows line endings.
3220 The tabulator spacing
3221 \begin_inset LatexCommand \index{tabulator spacing (8 columns)}
3225 used in the project is 8.
3226 Although a tabulator spacing of 8 is a sensible choice for programmers
3227 (it's a power of 2 and allows to display 8/16 bit signed variables without
3228 loosing columns) the plan is to move towards using only spaces in the source.
3231 Building SDCC Using Microsoft Visual C++ 6.0/NET (MSVC)
3236 Download the source package
3238 either from the SDCC CVS repository or from the
3239 \begin_inset LatexCommand \url[nightly snapshots]{http://sdcc.sourceforge.net/snap.php}
3245 , it will be named something like sdcc
3252 SDCC is distributed with all the projects, workspaces, and files you need
3253 to build it using Visual C++ 6.0/NET (except for sdcdb.exe which currently
3254 doesn't build under MSVC).
3255 The workspace name is 'sdcc.dsw'.
3256 Please note that as it is now, all the executables are created in a folder
3260 Once built you need to copy the executables from sdcc
3264 bin before running SDCC.
3269 WARNING: Visual studio is very picky with line terminations; it expects
3270 the 0x0d, 0x0a DOS style line endings, not the 0x0a Unix style line endings.
3271 If you are getting a message such as "This makefile was not generated by
3272 Developer Studio etc.
3274 \begin_inset Quotes srd
3277 when opening the sdcc.dsw workspace or any of the *.dsp projects, then you
3278 need to convert the Unix style line endings to DOS style line endings.
3279 To do so you can use the
3280 \begin_inset Quotes sld
3284 \begin_inset Quotes srd
3287 utility freely available on the internet.
3288 Doug Hawkins reported in the sdcc-user list that this works:
3296 SDCC> unix2dos sdcc.dsw
3302 SDCC> for /R %I in (*.dsp) do @unix2dos "%I"
3306 In order to build SDCC with MSVC you need win32 executables of bison.exe,
3307 flex.exe, and gawk.exe.
3308 One good place to get them is
3309 \begin_inset LatexCommand \url[here]{http://unxutils.sourceforge.net}
3317 Download the file UnxUtils
3318 \begin_inset LatexCommand \index{UnxUtils}
3323 Now you have to install the utilities and setup MSVC so it can locate the
3325 Here there are two alternatives (choose one!):
3332 a) Extract UnxUtils.zip to your C:
3334 hard disk PRESERVING the original paths, otherwise bison won't work.
3335 (If you are using WinZip make certain that 'Use folder names' is selected)
3339 b) In the Visual C++ IDE click Tools, Options, select the Directory tab,
3340 in 'Show directories for:' select 'Executable files', and in the directories
3341 window add a new path: 'C:
3351 (As a side effect, you get a bunch of Unix utilities that could be useful,
3352 such as diff and patch.)
3359 This one avoids extracting a bunch of files you may not use, but requires
3364 a) Create a directory were to put the tools needed, or use a directory already
3372 b) Extract 'bison.exe', 'bison.hairy', 'bison.simple', 'flex.exe', and gawk.exe
3373 to such directory WITHOUT preserving the original paths.
3374 (If you are using WinZip make certain that 'Use folder names' is not selected)
3378 c) Rename bison.exe to '_bison.exe'.
3382 d) Create a batch file 'bison.bat' in 'C:
3386 ' and add these lines:
3406 _bison %1 %2 %3 %4 %5 %6 %7 %8 %9
3410 Steps 'c' and 'd' are needed because bison requires by default that the
3411 files 'bison.simple' and 'bison.hairy' reside in some weird Unix directory,
3412 '/usr/local/share/' I think.
3413 So it is necessary to tell bison where those files are located if they
3414 are not in such directory.
3415 That is the function of the environment variables BISON_SIMPLE and BISON_HAIRY.
3419 e) In the Visual C++ IDE click Tools, Options, select the Directory tab,
3420 in 'Show directories for:' select 'Executable files', and in the directories
3421 window add a new path: 'c:
3424 Note that you can use any other path instead of 'c:
3426 util', even the path where the Visual C++ tools are, probably: 'C:
3430 Microsoft Visual Studio
3435 So you don't have to execute step 'e' :)
3439 Open 'sdcc.dsw' in Visual Studio, click 'build all', when it finishes copy
3440 the executables from sdcc
3444 bin, and you can compile using SDCC.
3447 Building SDCC Using Borland
3450 From the sdcc directory, run the command "make -f Makefile.bcc".
3451 This should regenerate all the .exe files in the bin directory except for
3452 sdcdb.exe (which currently doesn't build under Borland C++).
3455 If you modify any source files and need to rebuild, be aware that the dependenci
3456 es may not be correctly calculated.
3457 The safest option is to delete all .obj files and run the build again.
3458 From a Cygwin BASH prompt, this can easily be done with the command (be
3459 sure you are in the sdcc directory):
3469 ( -name '*.obj' -o -name '*.lib' -o -name '*.rul'
3471 ) -print -exec rm {}
3480 or on Windows NT/2000/XP from the command prompt with the command:
3487 del /s *.obj *.lib *.rul
3490 from the sdcc directory.
3493 Windows Install Using a ZIP Package
3496 Download the binary zip package from
3497 \begin_inset LatexCommand \url{http://sdcc.sf.net/snap.php}
3501 and unpack it using your favorite unpacking tool (gunzip, WinZip, etc).
3502 This should unpack to a group of sub-directories.
3503 An example directory structure after unpacking the mingw32 package is:
3508 bin for the executables, c:
3516 lib for the include and libraries.
3519 Adjust your environment variable PATH to include the location of the bin
3520 directory or start sdcc using the full path.
3523 Windows Install Using the Setup Program
3524 \begin_inset LatexCommand \label{sub:Windows-Install}
3531 Download the setup program
3533 sdcc-x.y.z-setup.exe
3535 for an official release from
3538 \begin_inset LatexCommand \url{http://sf.net/project/showfiles.php?group_id=599}
3542 or a setup program for one of the snapshots
3544 sdcc_yyyymmdd_setup.exe
3547 \begin_inset LatexCommand \url{http://sdcc.sf.net/snap.php}
3552 A windows typical installer will guide you through the installation process.
3555 Building the Documentation
3558 If the necessary tools (LyX, LaTeX, LaTeX2HTML) are installed it is as easy
3559 as changing into the doc directory and typing
3563 \begin_inset Quotes srd
3567 \begin_inset Quotes srd
3574 You're invited to make changes and additions to this manual (sdcc/doc/sdccman.ly
3577 \begin_inset LatexCommand \url{http://www.lyx.org}
3581 as editor this is straightforward.
3582 Prebuilt documentation in html and pdf format is available from
3583 \begin_inset LatexCommand \url{http://sdcc.sf.net/snap.php}
3590 Reading the Documentation
3593 Currently reading the document in pdf format is recommended, as for unknown
3594 reason the hyperlinks are working there whereas in the html version they
3601 If you should know why please drop us a note
3607 You'll find the pdf version
3608 \begin_inset LatexCommand \index{PDF version of this document}
3613 \begin_inset LatexCommand \url{http://sdcc.sf.net/doc/sdccman.pdf}
3621 \begin_inset LatexCommand \index{HTML version of this document}
3626 \begin_inset LatexCommand \url{http://sdcc.sf.net/doc/sdccman.html/index.html}
3632 This documentation is in some aspects different from a commercial documentation:
3636 It tries to document SDCC for several processor architectures in one document
3637 (commercially these probably would be separate documents/products).
3639 \begin_inset LatexCommand \index{Status of documentation}
3643 currently matches SDCC for mcs51 and DS390 best and does give too few informati
3645 Z80, PIC14, PIC16 and HC08.
3648 There are many references pointing away from this documentation.
3649 Don't let this distract you.
3651 was a reference like
3652 \begin_inset LatexCommand \url{http://www.opencores.org}
3656 together with a statement
3657 \begin_inset Quotes sld
3660 some processors which are targetted by SDCC can be implemented in a
3677 \begin_inset LatexCommand \index{fpga (field programmable gate array)}
3682 \begin_inset Quotes srd
3685 we expect you to have a quick look there and come back.
3686 If you read this you are on the right track.
3689 Some sections attribute more space to problems, restrictions and warnings
3690 than to the solution.
3693 The installation section and the section about the debugger is intimidating.
3696 There are still lots of typos and there are more different writing styles
3700 Testing the SDCC Compiler
3701 \begin_inset LatexCommand \label{sec:Testing-the-SDCC}
3708 The first thing you should do after installing your SDCC compiler is to
3724 \begin_inset LatexCommand \index{version}
3731 at the prompt, and the program should run and tell you the version.
3732 If it doesn't run, or gives a message about not finding sdcc program, then
3733 you need to check over your installation.
3734 Make sure that the sdcc bin directory is in your executable search path
3735 defined by the PATH environment setting (
3740 \begin_inset LatexCommand \ref{sub:Install-Trouble-shooting}
3747 Install trouble-shooting for suggestions
3750 Make sure that the sdcc program is in the bin folder, if not perhaps something
3751 did not install correctly.
3759 is commonly installed as described in section
3760 \begin_inset Quotes sld
3763 Install and search paths
3764 \begin_inset Quotes srd
3773 Make sure the compiler works on a very simple example.
3774 Type in the following test.c program using your favorite
3800 Compile this using the following command:
3809 If all goes well, the compiler will generate a test.asm and test.rel file.
3810 Congratulations, you've just compiled your first program with SDCC.
3811 We used the -c option to tell SDCC not to link the generated code, just
3812 to keep things simple for this step.
3820 The next step is to try it with the linker.
3830 If all goes well the compiler will link with the libraries and produce
3831 a test.ihx output file.
3836 (no test.ihx, and the linker generates warnings), then the problem is most
3845 usr/local/share/sdcc/lib directory
3852 \begin_inset LatexCommand \ref{sub:Install-Trouble-shooting}
3859 Install trouble-shooting for suggestions).
3867 The final test is to ensure
3875 header files and libraries.
3876 Edit test.c and change it to the following:
3893 strcpy(str1, "testing");
3900 Compile this by typing
3907 This should generate a test.ihx output file, and it should give no warnings
3908 such as not finding the string.h file.
3909 If it cannot find the string.h file, then the problem is that
3913 cannot find the /usr/local/share/sdcc/include directory
3920 \begin_inset LatexCommand \ref{sub:Install-Trouble-shooting}
3927 Install trouble-shooting section for suggestions).
3945 \begin_inset LatexCommand \index{-\/-print-search-dirs}
3949 to find exactly where SDCC is looking for the include and lib files.
3952 Install Trouble-shooting
3953 \begin_inset LatexCommand \label{sub:Install-Trouble-shooting}
3958 \begin_inset LatexCommand \index{Install trouble-shooting}
3965 If SDCC does not build correctly
3968 A thing to try is starting from scratch by unpacking the .tgz source package
3969 again in an empty directory.
3977 ./configure 2>&1 | tee configure.log
3991 make 2>&1 | tee make.log
3998 If anything goes wrong, you can review the log files to locate the problem.
3999 Or a relevant part of this can be attached to an email that could be helpful
4000 when requesting help from the mailing list.
4004 \begin_inset Quotes sld
4008 \begin_inset Quotes srd
4015 \begin_inset Quotes sld
4019 \begin_inset Quotes srd
4022 command is a script that analyzes your system and performs some configuration
4023 to ensure the source package compiles on your system.
4024 It will take a few minutes to run, and will compile a few tests to determine
4025 what compiler features are installed.
4029 \begin_inset Quotes sld
4033 \begin_inset Quotes srd
4039 This runs the GNU make tool, which automatically compiles all the source
4040 packages into the final installed binary executables.
4044 \begin_inset Quotes sld
4048 \begin_inset Quotes erd
4054 This will install the compiler, other executables libraries and include
4055 files into the appropriate directories.
4057 \begin_inset LatexCommand \ref{sub:Install-paths}
4063 \begin_inset LatexCommand \ref{sub:Search-Paths}
4068 about install and search paths.
4070 On most systems you will need super-user privileges to do this.
4076 SDCC is not just a compiler, but a collection of tools by various developers.
4077 These include linkers, assemblers, simulators and other components.
4078 Here is a summary of some of the components.
4079 Note that the included simulator and assembler have separate documentation
4080 which you can find in the source package in their respective directories.
4081 As SDCC grows to include support for other processors, other packages from
4082 various developers are included and may have their own sets of documentation.
4086 You might want to look at the files which are installed in <installdir>.
4087 At the time of this writing, we find the following programs for gcc-builds:
4091 In <installdir>/bin:
4094 sdcc - The compiler.
4097 sdcpp - The C preprocessor.
4100 asx8051 - The assembler for 8051 type processors.
4107 as-gbz80 - The Z80 and GameBoy Z80 assemblers.
4110 aslink -The linker for 8051 type processors.
4117 link-gbz80 - The Z80 and GameBoy Z80 linkers.
4120 s51 - The ucSim 8051 simulator.
4123 sdcdb - The source debugger.
4126 packihx - A tool to pack (compress) Intel hex files.
4129 In <installdir>/share/sdcc/include
4135 In <installdir>/share/sdcc/lib
4138 the subdirs src and small, large, z80, gbz80 and ds390 with the precompiled
4142 In <installdir>/share/sdcc/doc
4148 As development for other processors proceeds, this list will expand to include
4149 executables to support processors like AVR, PIC, etc.
4155 This is the actual compiler, it in turn uses the c-preprocessor and invokes
4156 the assembler and linkage editor.
4159 sdcpp - The C-Preprocessor
4163 \begin_inset LatexCommand \index{sdcpp (preprocessor)}
4167 is a modified version of the GNU preprocessor.
4168 The C preprocessor is used to pull in #include sources, process #ifdef
4169 statements, #defines and so on.
4180 - The Assemblers and Linkage Editors
4183 This is retargettable assembler & linkage editor, it was developed by Alan
4185 John Hartman created the version for 8051, and I (Sandeep) have made some
4186 enhancements and bug fixes for it to work properly with SDCC.
4193 \begin_inset LatexCommand \index{s51}
4197 is a freeware, opensource simulator developed by Daniel Drotos.
4198 The simulator is built as part of the build process.
4199 For more information visit Daniel's web site at:
4200 \begin_inset LatexCommand \url{http://mazsola.iit.uni-miskolc.hu/~drdani/embedded/s51}
4205 It currently supports the core mcs51, the Dallas DS80C390 and the Phillips
4209 sdcdb - Source Level Debugger
4213 \begin_inset LatexCommand \index{sdcdb (debugger)}
4217 is the companion source level debugger.
4218 More about sdcdb in section
4219 \begin_inset LatexCommand \ref{cha:Debugging-with-SDCDB}
4224 The current version of the debugger uses Daniel's Simulator S51
4225 \begin_inset LatexCommand \index{s51}
4229 , but can be easily changed to use other simulators.
4239 Single Source File Projects
4242 For single source file 8051 projects the process is very simple.
4243 Compile your programs with the following command
4246 "sdcc sourcefile.c".
4250 This will compile, assemble and link your source file.
4251 Output files are as follows:
4255 \begin_inset LatexCommand \index{<file>.asm}
4260 \begin_inset LatexCommand \index{Assembler source}
4264 file created by the compiler
4268 \begin_inset LatexCommand \index{<file>.lst}
4273 \begin_inset LatexCommand \index{Assembler listing}
4277 file created by the Assembler
4281 \begin_inset LatexCommand \index{<file>.rst}
4286 \begin_inset LatexCommand \index{Assembler listing}
4290 file updated with linkedit information, created by linkage editor
4294 \begin_inset LatexCommand \index{<file>.sym}
4299 \begin_inset LatexCommand \index{Symbol listing}
4303 for the sourcefile, created by the assembler
4307 \begin_inset LatexCommand \index{<file>.rel}
4312 \begin_inset LatexCommand \index{<file>.o}
4317 \begin_inset LatexCommand \index{Object file}
4321 created by the assembler, input to Linkage editor
4325 \begin_inset LatexCommand \index{<file>.map}
4330 \begin_inset LatexCommand \index{Memory map}
4334 for the load module, created by the Linker
4338 \begin_inset LatexCommand \index{<file>.mem}
4342 - A file with a summary of the memory usage
4346 \begin_inset LatexCommand \index{<file>.ihx}
4350 - The load module in Intel hex format
4351 \begin_inset LatexCommand \index{Intel hex format}
4355 (you can select the Motorola S19 format
4356 \begin_inset LatexCommand \index{Motorola S19 format}
4371 \begin_inset LatexCommand \index{-\/-out-fmt-s19}
4376 If you need another format you might want to use
4383 \begin_inset LatexCommand \index{objdump (tool)}
4394 \begin_inset LatexCommand \index{srecord (bin, hex, ... tool)}
4399 Both formats are documented in the documentation of srecord
4400 \begin_inset LatexCommand \index{srecord (bin, hex, ... tool)}
4408 \begin_inset LatexCommand \index{<file>.adb}
4412 - An intermediate file containing debug information needed to create the
4424 \begin_inset LatexCommand \index{-\/-debug}
4432 \begin_inset LatexCommand \index{<file>.cdb}
4436 - An optional file (with -
4446 -debug) containing debug information.
4447 The format is documented in cdbfileformat.pdf
4452 \begin_inset LatexCommand \index{<file> (no extension)}
4456 An optional AOMF or AOMF51
4457 \begin_inset LatexCommand \index{AOMF, AOMF51}
4461 file containing debug information (generated with option -
4488 ormat is commonly used by third party tools (debuggers
4489 \begin_inset LatexCommand \index{Debugger}
4493 , simulators, emulators)
4497 \begin_inset LatexCommand \index{<file>.dump*}
4501 - Dump file to debug the compiler it self (generated with option -
4511 -dumpall) (see section
4512 \begin_inset LatexCommand \ref{sub:Intermediate-Dump-Options}
4518 \begin_inset LatexCommand \ref{sub:The-anatomy-of}
4524 \begin_inset Quotes sld
4527 Anatomy of the compiler
4528 \begin_inset Quotes srd
4534 Projects with Multiple Source Files
4537 SDCC can compile only ONE file at a time.
4538 Let us for example assume that you have a project containing the following
4543 foo1.c (contains some functions)
4545 foo2.c (contains some more functions)
4547 foomain.c (contains more functions and the function main)
4555 The first two files will need to be compiled separately with the commands:
4587 Then compile the source file containing the
4592 \begin_inset LatexCommand \index{Linker}
4596 the files together with the following command:
4604 foomain.c\SpecialChar ~
4605 foo1.rel\SpecialChar ~
4610 \begin_inset LatexCommand \index{<file>.rel}
4622 can be separately compiled as well:
4633 sdcc foomain.rel foo1.rel foo2.rel
4640 The file containing the
4655 file specified in the command line, since the linkage editor processes
4656 file in the order they are presented to it.
4657 The linker is invoked from SDCC using a script file with extension .lnk
4658 \begin_inset LatexCommand \index{<file>.lnk}
4663 You can view this file to troubleshoot linking problems such as those arising
4664 from missing libraries.
4667 Projects with Additional Libraries
4668 \begin_inset LatexCommand \index{Libraries}
4675 Some reusable routines may be compiled into a library, see the documentation
4676 for the assembler and linkage editor (which are in <installdir>/share/sdcc/doc)
4680 \begin_inset LatexCommand \index{<file>.lib}
4687 Libraries created in this manner can be included in the command line.
4688 Make sure you include the -L <library-path> option to tell the linker where
4689 to look for these files if they are not in the current directory.
4690 Here is an example, assuming you have the source file
4702 (if that is not the same as your current project):
4709 sdcc foomain.c foolib.lib -L mylib
4720 must be an absolute path name.
4724 The most efficient way to use libraries is to keep separate modules in separate
4726 The lib file now should name all the modules.rel
4727 \begin_inset LatexCommand \index{<file>.rel}
4732 For an example see the standard library file
4736 in the directory <installdir>/share/lib/small.
4739 Using sdcclib to Create and Manage Libraries
4740 \begin_inset LatexCommand \index{sdcclib}
4747 Alternatively, instead of having a .rel file for each entry on the library
4748 file as described in the preceding section, sdcclib can be used to embed
4749 all the modules belonging to such library in the library file itself.
4750 This results in a larger library file, but it greatly reduces the number
4751 of disk files accessed by the linker.
4752 Additionally, the packed library file contains an index of all include
4753 modules and symbols that significantly speeds up the linking process.
4754 To display a list of options supported by sdcclib type:
4763 \begin_inset LatexCommand \index{sdcclib}
4774 To create a new library file, start by compiling all the required modules.
4812 This will create files _divsint.rel, _divuint.rel, _modsint.rel, _moduint.rel,
4814 The next step is to add the .rel files to the library file:
4822 sdcclib libint.lib _divsint.rel
4825 \begin_inset LatexCommand \index{sdcclib}
4835 sdcclib libint.lib _divuint.rel
4841 sdcclib libint.lib _modsint.rel
4847 sdcclib libint.lib _moduint.rel
4853 sdcclib libint.lib _mulint.rel
4860 If the file already exists in the library, it will be replaced.
4861 To see what modules and symbols are included in the library, options -s
4862 and -m are available.
4870 sdcclib -s libint.lib
4873 \begin_inset LatexCommand \index{sdcclib}
4983 If the source files are compiled using -
4994 \begin_inset LatexCommand \index{-\/-debug}
4998 , the corresponding debug information file .adb will be include in the library
5000 The library files created with sdcclib are plain text files, so they can
5001 be viewed with a text editor.
5002 It is not recomended to modify a library file created with sdcclib using
5003 a text editor, as there are file indexes numbers located accross the file
5004 used by the linker to quickly locate the required module to link.
5005 Once a .rel file (as well as a .adb file) is added to a library using sdcclib,
5006 it can be safely deleted, since all the information required for linking
5007 is embedded in the library file itself.
5008 Library files created using sdcclib are used as described in the preceding
5012 Command Line Options
5013 \begin_inset LatexCommand \index{Command Line Options}
5020 Processor Selection Options
5021 \begin_inset LatexCommand \index{Options processor selection}
5026 \begin_inset LatexCommand \index{Processor selection options}
5032 \labelwidthstring 00.00.0000
5037 \begin_inset LatexCommand \index{-mmcs51}
5043 Generate code for the Intel MCS51
5044 \begin_inset LatexCommand \index{MCS51}
5048 family of processors.
5049 This is the default processor target.
5051 \labelwidthstring 00.00.0000
5056 \begin_inset LatexCommand \index{-mds390}
5062 Generate code for the Dallas DS80C390
5063 \begin_inset LatexCommand \index{DS80C390}
5069 \labelwidthstring 00.00.0000
5074 \begin_inset LatexCommand \index{-mds400}
5080 Generate code for the Dallas DS80C400
5081 \begin_inset LatexCommand \index{DS80C400}
5087 \labelwidthstring 00.00.0000
5092 \begin_inset LatexCommand \index{-mhc08}
5098 Generate code for the Freescale/Motorola HC08
5099 \begin_inset LatexCommand \index{HC08}
5103 family of processors.
5105 \labelwidthstring 00.00.0000
5110 \begin_inset LatexCommand \index{-mz80}
5116 Generate code for the Zilog Z80
5117 \begin_inset LatexCommand \index{Z80}
5121 family of processors.
5123 \labelwidthstring 00.00.0000
5128 \begin_inset LatexCommand \index{-mgbz80}
5134 Generate code for the GameBoy Z80
5135 \begin_inset LatexCommand \index{gbz80 (GameBoy Z80)}
5139 processor (Not actively maintained).
5141 \labelwidthstring 00.00.0000
5146 \begin_inset LatexCommand \index{-mavr}
5152 Generate code for the Atmel AVR
5153 \begin_inset LatexCommand \index{AVR}
5157 processor (In development, not complete).
5158 AVR users should probably have a look at winavr
5159 \begin_inset LatexCommand \url{http://sourceforge.net/projects/winavr}
5164 \begin_inset LatexCommand \url{http://www.avrfreaks.net/index.php?name=PNphpBB2&file=index}
5171 I think it is fair to direct users there for now.
5172 Open source is also about avoiding unnecessary work .
5173 But I didn't find the 'official' link.
5175 \labelwidthstring 00.00.0000
5180 \begin_inset LatexCommand \index{-mpic14}
5186 Generate code for the Microchip PIC 14
5187 \begin_inset LatexCommand \index{PIC14}
5191 -bit processors (p16f84 and variants.
5192 In development, not complete).
5195 p16f627 p16f628 p16f84 p16f873 p16f877?
5197 \labelwidthstring 00.00.0000
5202 \begin_inset LatexCommand \index{-mpic16}
5208 Generate code for the Microchip PIC 16
5209 \begin_inset LatexCommand \index{PIC16}
5213 -bit processors (p18f452 and variants.
5214 In development, not complete).
5216 \labelwidthstring 00.00.0000
5222 Generate code for the Toshiba TLCS-900H
5223 \begin_inset LatexCommand \index{TLCS-900H}
5227 processor (Not maintained, not complete).
5229 \labelwidthstring 00.00.0000
5234 \begin_inset LatexCommand \index{-mxa51}
5240 Generate code for the Phillips XA51
5241 \begin_inset LatexCommand \index{XA51}
5245 processor (Not maintained, not complete).
5248 Preprocessor Options
5249 \begin_inset LatexCommand \index{Options preprocessor}
5254 \begin_inset LatexCommand \index{Preprocessor options}
5259 \begin_inset LatexCommand \index{sdcpp (preprocessor)}
5265 \labelwidthstring 00.00.0000
5270 \begin_inset LatexCommand \index{-I<path>}
5276 The additional location where the pre processor will look for <..h> or
5277 \begin_inset Quotes eld
5281 \begin_inset Quotes erd
5286 \labelwidthstring 00.00.0000
5291 \begin_inset LatexCommand \index{-D<macro[=value]>}
5297 Command line definition of macros.
5298 Passed to the preprocessor.
5300 \labelwidthstring 00.00.0000
5305 \begin_inset LatexCommand \index{-M}
5311 Tell the preprocessor to output a rule suitable for make describing the
5312 dependencies of each object file.
5313 For each source file, the preprocessor outputs one make-rule whose target
5314 is the object file name for that source file and whose dependencies are
5315 all the files `#include'd in it.
5316 This rule may be a single line or may be continued with `
5318 '-newline if it is long.
5319 The list of rules is printed on standard output instead of the preprocessed
5322 \begin_inset LatexCommand \index{-E}
5328 \labelwidthstring 00.00.0000
5333 \begin_inset LatexCommand \index{-C}
5339 Tell the preprocessor not to discard comments.
5340 Used with the `-E' option.
5342 \labelwidthstring 00.00.0000
5347 \begin_inset LatexCommand \index{-MM}
5358 Like `-M' but the output mentions only the user header files included with
5360 \begin_inset Quotes eld
5364 System header files included with `#include <file>' are omitted.
5366 \labelwidthstring 00.00.0000
5371 \begin_inset LatexCommand \index{-Aquestion(answer)}
5377 Assert the answer answer for question, in case it is tested with a preprocessor
5378 conditional such as `#if #question(answer)'.
5379 `-A-' disables the standard assertions that normally describe the target
5382 \labelwidthstring 00.00.0000
5387 \begin_inset LatexCommand \index{-Umacro}
5393 Undefine macro macro.
5394 `-U' options are evaluated after all `-D' options, but before any `-include'
5395 and `-imacros' options.
5397 \labelwidthstring 00.00.0000
5402 \begin_inset LatexCommand \index{-dM}
5408 Tell the preprocessor to output only a list of the macro definitions that
5409 are in effect at the end of preprocessing.
5410 Used with the `-E' option.
5412 \labelwidthstring 00.00.0000
5417 \begin_inset LatexCommand \index{-dD}
5423 Tell the preprocessor to pass all macro definitions into the output, in
5424 their proper sequence in the rest of the output.
5426 \labelwidthstring 00.00.0000
5431 \begin_inset LatexCommand \index{-dN}
5442 Like `-dD' except that the macro arguments and contents are omitted.
5443 Only `#define name' is included in the output.
5445 \labelwidthstring 00.00.0000
5450 preprocessorOption[,preprocessorOption]
5453 \begin_inset LatexCommand \index{-Wp preprocessorOption[,preprocessorOption]}
5458 Pass the preprocessorOption to the preprocessor
5463 \begin_inset LatexCommand \index{sdcpp (preprocessor)}
5468 SDCC uses an adapted version of the preprocessor cpp of the GNU Compiler
5469 Collection (gcc), if you need more dedicated options please refer to the
5471 \begin_inset LatexCommand \htmlurl{http://www.gnu.org/software/gcc/onlinedocs/}
5479 \begin_inset LatexCommand \index{Options linker}
5484 \begin_inset LatexCommand \index{Linker options}
5490 \labelwidthstring 00.00.0000
5510 \begin_inset LatexCommand \index{-\/-lib-path <path>}
5515 \begin_inset LatexCommand \index{-L -\/-lib-path}
5522 <absolute path to additional libraries> This option is passed to the linkage
5523 editor's additional libraries
5524 \begin_inset LatexCommand \index{Libraries}
5529 The path name must be absolute.
5530 Additional library files may be specified in the command line.
5531 See section Compiling programs for more details.
5533 \labelwidthstring 00.00.0000
5550 \begin_inset LatexCommand \index{-\/-xram-loc <Value>}
5555 <Value> The start location of the external ram
5556 \begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
5560 , default value is 0.
5561 The value entered can be in Hexadecimal or Decimal format, e.g.: -
5571 -xram-loc 0x8000 or -
5583 \labelwidthstring 00.00.0000
5600 \begin_inset LatexCommand \index{-\/-code-loc <Value>}
5605 <Value> The start location of the code
5606 \begin_inset LatexCommand \index{code}
5610 segment, default value 0.
5611 Note when this option is used the interrupt vector table is also relocated
5612 to the given address.
5613 The value entered can be in Hexadecimal or Decimal format, e.g.: -
5623 -code-loc 0x8000 or -
5635 \labelwidthstring 00.00.0000
5652 \begin_inset LatexCommand \index{-\/-stack-loc <Value>}
5657 <Value> By default the stack
5658 \begin_inset LatexCommand \index{stack}
5662 is placed after the data segment.
5663 Using this option the stack can be placed anywhere in the internal memory
5665 The value entered can be in Hexadecimal or Decimal format, e.g.
5676 -stack-loc 0x20 or -
5687 Since the sp register is incremented before a push or call, the initial
5688 sp will be set to one byte prior the provided value.
5689 The provided value should not overlap any other memory areas such as used
5690 register banks or the data segment and with enough space for the current
5708 \begin_inset LatexCommand \index{-\/-pack-iram}
5712 option (which is now a default setting) will override this setting, so
5713 you should also specify the
5729 \begin_inset LatexCommand \index{-\/-no-pack-iram}
5733 option if you need to manually place the stack.
5735 \labelwidthstring 00.00.0000
5752 \begin_inset LatexCommand \index{-\/-data-loc <Value>}
5757 <Value> The start location of the internal ram data
5758 \begin_inset LatexCommand \index{data (mcs51, ds390 storage class)}
5763 The value entered can be in Hexadecimal or Decimal format, eg.
5785 (By default, the start location of the internal ram data segment is set
5786 as low as possible in memory, taking into account the used register banks
5787 and the bit segment at address 0x20.
5788 For example if register banks 0 and 1 are used without bit variables, the
5789 data segment will be set, if -
5799 -data-loc is not used, to location 0x10.)
5801 \labelwidthstring 00.00.0000
5818 \begin_inset LatexCommand \index{-\/-idata-loc <Value>}
5823 <Value> The start location of the indirectly addressable internal ram
5824 \begin_inset LatexCommand \index{idata (mcs51, ds390 storage class)}
5828 of the 8051, default value is 0x80.
5829 The value entered can be in Hexadecimal or Decimal format, eg.
5840 -idata-loc 0x88 or -
5852 \labelwidthstring 00.00.0000
5869 <Value> The start location of the bit
5870 \begin_inset LatexCommand \index{bit}
5874 addressable internal ram of the 8051.
5880 Instead an option can be passed directly to the linker: -Wl\SpecialChar ~
5883 \labelwidthstring 00.00.0000
5898 \begin_inset LatexCommand \index{-\/-out-fmt-ihx}
5907 The linker output (final object code) is in Intel Hex format.
5908 \begin_inset LatexCommand \index{Intel hex format}
5912 This is the default option.
5913 The format itself is documented in the documentation of srecord
5914 \begin_inset LatexCommand \index{srecord (bin, hex, ... tool)}
5920 \labelwidthstring 00.00.0000
5935 \begin_inset LatexCommand \index{-\/-out-fmt-s19}
5944 The linker output (final object code) is in Motorola S19 format
5945 \begin_inset LatexCommand \index{Motorola S19 format}
5950 The format itself is documented in the documentation of srecord.
5952 \labelwidthstring 00.00.0000
5967 \begin_inset LatexCommand \index{-\/-out-fmt-s19}
5976 The linker output (final object code) is in ELF format
5977 \begin_inset LatexCommand \index{ELF format}
5982 (Currently only supported for the HC08 processors)
5984 \labelwidthstring 00.00.0000
5989 linkOption[,linkOption]
5992 \begin_inset LatexCommand \index{-Wl linkOption[,linkOption]}
5997 Pass the linkOption to the linker.
5998 See file sdcc/as/doc/asxhtm.html for more on linker options.
6002 \begin_inset LatexCommand \index{Options MCS51}
6007 \begin_inset LatexCommand \index{MCS51 options}
6013 \labelwidthstring 00.00.0000
6028 \begin_inset LatexCommand \index{-\/-model-small}
6039 Generate code for Small Model programs, see section Memory Models for more
6041 This is the default model.
6043 \labelwidthstring 00.00.0000
6058 \begin_inset LatexCommand \index{-\/-model-large}
6064 Generate code for Large model programs, see section Memory Models for more
6066 If this option is used all source files in the project have to be compiled
6069 \labelwidthstring 00.00.0000
6084 \begin_inset LatexCommand \index{-\/-xstack}
6090 Uses a pseudo stack in the first 256 bytes in the external ram for allocating
6091 variables and passing parameters.
6093 \begin_inset LatexCommand \ref{sub:External-Stack}
6098 External Stack for more details.
6100 \labelwidthstring 00.00.0000
6118 \begin_inset LatexCommand \index{-\/-iram-size <Value>}
6122 Causes the linker to check if the internal ram usage is within limits of
6125 \labelwidthstring 00.00.0000
6143 \begin_inset LatexCommand \index{-\/-xram-size <Value>}
6147 Causes the linker to check if the external ram usage is within limits of
6150 \labelwidthstring 00.00.0000
6168 \begin_inset LatexCommand \index{-\/-code-size <Value>}
6172 Causes the linker to check if the code memory usage is within limits of
6175 \labelwidthstring 00.00.0000
6193 \begin_inset LatexCommand \index{-\/-stack-size <Value>}
6197 Causes the linker to check if there is at minimum <Value> bytes for stack.
6199 \labelwidthstring 00.00.0000
6217 \begin_inset LatexCommand \index{-\/-pack-iram}
6221 Causes the linker to use unused register banks for data variables and pack
6222 data, idata and stack together.
6223 This is the default now.
6225 \labelwidthstring 00.00.0000
6243 \begin_inset LatexCommand \index{-\/-no-pack-iram}
6247 Causes the linker to use old style for allocating memory areas.
6250 DS390 / DS400 Options
6251 \begin_inset LatexCommand \index{Options DS390}
6256 \begin_inset LatexCommand \index{DS390 options}
6262 \labelwidthstring 00.00.0000
6279 \begin_inset LatexCommand \index{-\/-model-flat24}
6289 Generate 24-bit flat mode code.
6290 This is the one and only that the ds390 code generator supports right now
6291 and is default when using
6296 See section Memory Models for more details.
6298 \labelwidthstring 00.00.0000
6313 \begin_inset LatexCommand \index{-\/-protect-sp-update}
6319 disable interrupts during ESP:SP updates.
6321 \labelwidthstring 00.00.0000
6338 \begin_inset LatexCommand \index{-\/-stack-10bit}
6342 Generate code for the 10 bit stack mode of the Dallas DS80C390 part.
6343 This is the one and only that the ds390 code generator supports right now
6344 and is default when using
6349 In this mode, the stack is located in the lower 1K of the internal RAM,
6350 which is mapped to 0x400000.
6351 Note that the support is incomplete, since it still uses a single byte
6352 as the stack pointer.
6353 This means that only the lower 256 bytes of the potential 1K stack space
6354 will actually be used.
6355 However, this does allow you to reclaim the precious 256 bytes of low RAM
6356 for use for the DATA and IDATA segments.
6357 The compiler will not generate any code to put the processor into 10 bit
6359 It is important to ensure that the processor is in this mode before calling
6360 any re-entrant functions compiled with this option.
6361 In principle, this should work with the
6374 \begin_inset LatexCommand \index{-\/-stack-auto}
6380 option, but that has not been tested.
6381 It is incompatible with the
6394 \begin_inset LatexCommand \index{-\/-xstack}
6401 It also only makes sense if the processor is in 24 bit contiguous addressing
6414 -model-flat24 option
6418 \labelwidthstring 00.00.0000
6433 \begin_inset LatexCommand \index{-\/-stack-probe}
6439 insert call to function __stack_probe at each function prologue.
6441 \labelwidthstring 00.00.0000
6456 \begin_inset LatexCommand \index{-\/-tini-libid}
6462 <nnnn> LibraryID used in -mTININative.
6465 \labelwidthstring 00.00.0000
6480 \begin_inset LatexCommand \index{-\/-use-accelerator}
6486 generate code for DS390 Arithmetic Accelerator.
6491 \begin_inset LatexCommand \index{Options Z80}
6496 \begin_inset LatexCommand \index{Z80 options}
6502 \labelwidthstring 00.00.0000
6519 \begin_inset LatexCommand \index{-\/-callee-saves-bc}
6529 Force a called function to always save BC.
6531 \labelwidthstring 00.00.0000
6548 \begin_inset LatexCommand \index{-\/-no-std-crt0}
6552 When linking, skip the standard crt0.o object file.
6553 You must provide your own crt0.o for your system when linking.
6557 Optimization Options
6558 \begin_inset LatexCommand \index{Options optimization}
6563 \begin_inset LatexCommand \index{Optimization options}
6569 \labelwidthstring 00.00.0000
6584 \begin_inset LatexCommand \index{-\/-nogcse}
6590 Will not do global subexpression elimination, this option may be used when
6591 the compiler creates undesirably large stack/data spaces to store compiler
6601 \begin_inset LatexCommand \index{sloc (spill location)}
6606 A warning message will be generated when this happens and the compiler
6607 will indicate the number of extra bytes it allocated.
6608 It is recommended that this option NOT be used, #pragma\SpecialChar ~
6610 \begin_inset LatexCommand \index{\#pragma nogcse}
6614 can be used to turn off global subexpression elimination
6615 \begin_inset LatexCommand \index{Subexpression elimination}
6619 for a given function only.
6621 \labelwidthstring 00.00.0000
6636 \begin_inset LatexCommand \index{-\/-noinvariant}
6642 Will not do loop invariant optimizations, this may be turned off for reasons
6643 explained for the previous option.
6644 For more details of loop optimizations performed see Loop Invariants in
6646 \begin_inset LatexCommand \ref{sub:Loop-Optimizations}
6651 It is recommended that this option NOT be used, #pragma\SpecialChar ~
6653 \begin_inset LatexCommand \index{\#pragma noinvariant}
6657 can be used to turn off invariant optimizations for a given function only.
6659 \labelwidthstring 00.00.0000
6674 \begin_inset LatexCommand \index{-\/-noinduction}
6680 Will not do loop induction optimizations, see section strength reduction
6682 It is recommended that this option is NOT used, #pragma\SpecialChar ~
6684 \begin_inset LatexCommand \index{\#pragma noinduction}
6688 can be used to turn off induction optimizations for a given function only.
6690 \labelwidthstring 00.00.0000
6705 \begin_inset LatexCommand \index{-\/-nojtbound}
6716 Will not generate boundary condition check when switch statements
6717 \begin_inset LatexCommand \index{switch statement}
6721 are implemented using jump-tables.
6723 \begin_inset LatexCommand \ref{sub:'switch'-Statements}
6728 Switch Statements for more details.
6729 It is recommended that this option is NOT used, #pragma\SpecialChar ~
6731 \begin_inset LatexCommand \index{\#pragma nojtbound}
6735 can be used to turn off boundary checking for jump tables for a given function
6738 \labelwidthstring 00.00.0000
6753 \begin_inset LatexCommand \index{-\/-noloopreverse}
6762 Will not do loop reversal
6763 \begin_inset LatexCommand \index{Loop reversing}
6769 \labelwidthstring 00.00.0000
6786 \begin_inset LatexCommand \index{-\/-nolabelopt }
6790 Will not optimize labels (makes the dumpfiles more readable).
6792 \labelwidthstring 00.00.0000
6807 \begin_inset LatexCommand \index{-\/-no-xinit-opt}
6813 Will not memcpy initialized data from code space into xdata space.
6814 This saves a few bytes in code space if you don't have initialized data
6815 \begin_inset LatexCommand \index{Variable initialization}
6821 \labelwidthstring 00.00.0000
6836 \begin_inset LatexCommand \index{-\/-nooverlay}
6842 The compiler will not overlay parameters and local variables of any function,
6843 see section Parameters and local variables for more details.
6845 \labelwidthstring 00.00.0000
6860 \begin_inset LatexCommand \index{-\/-no-peep}
6866 Disable peep-hole optimization.
6868 \labelwidthstring 00.00.0000
6885 \begin_inset LatexCommand \index{-\/-peep-file}
6890 <filename> This option can be used to use additional rules to be used by
6891 the peep hole optimizer.
6893 \begin_inset LatexCommand \ref{sub:Peephole-Optimizer}
6898 Peep Hole optimizations for details on how to write these rules.
6900 \labelwidthstring 00.00.0000
6915 \begin_inset LatexCommand \index{-\/-peep-asm}
6921 Pass the inline assembler code through the peep hole optimizer.
6922 This can cause unexpected changes to inline assembler code, please go through
6923 the peephole optimizer
6924 \begin_inset LatexCommand \index{Peephole optimizer}
6928 rules defined in the source file tree '<target>/peeph.def' before using
6931 \labelwidthstring 00.00.0000
6946 \begin_inset LatexCommand \index{-\/-opt-code-speed}
6952 The compiler will optimize code generation towards fast code, possibly
6953 at the expense of code size.
6955 \labelwidthstring 00.00.0000
6970 \begin_inset LatexCommand \index{-\/-opt-code-size}
6976 The compiler will optimize code generation towards compact code, possibly
6977 at the expense of code speed.
6981 \begin_inset LatexCommand \index{Options other}
6987 \labelwidthstring 00.00.0000
7003 \begin_inset LatexCommand \index{-\/-compile-only}
7008 \begin_inset LatexCommand \index{-c -\/-compile-only}
7014 will compile and assemble the source, but will not call the linkage editor.
7016 \labelwidthstring 00.00.0000
7035 \begin_inset LatexCommand \index{-\/-c1mode}
7041 reads the preprocessed source from standard input and compiles it.
7042 The file name for the assembler output must be specified using the -o option.
7044 \labelwidthstring 00.00.0000
7049 \begin_inset LatexCommand \index{-E}
7055 Run only the C preprocessor.
7056 Preprocess all the C source files specified and output the results to standard
7059 \labelwidthstring 00.00.0000
7065 \begin_inset LatexCommand \index{-o <path/file>}
7071 The output path resp.
7072 file where everything will be placed.
7073 If the parameter is a path, it must have a trailing slash (or backslash
7074 for the Windows binaries) to be recognized as a path.
7077 \labelwidthstring 00.00.0000
7092 \begin_inset LatexCommand \index{-\/-stack-auto}
7103 All functions in the source file will be compiled as
7108 \begin_inset LatexCommand \index{reentrant}
7113 the parameters and local variables will be allocated on the stack
7114 \begin_inset LatexCommand \index{stack}
7120 \begin_inset LatexCommand \ref{sec:Parameters-and-Local-Variables}
7124 Parameters and Local Variables for more details.
7125 If this option is used all source files in the project should be compiled
7127 It automatically implies --int-long-reent and --float-reent.
7130 \labelwidthstring 00.00.0000
7145 \begin_inset LatexCommand \index{-\/-callee-saves}
7149 function1[,function2][,function3]....
7152 The compiler by default uses a caller saves convention for register saving
7153 across function calls, however this can cause unnecessary register pushing
7154 & popping when calling small functions from larger functions.
7155 This option can be used to switch the register saving convention for the
7156 function names specified.
7157 The compiler will not save registers when calling these functions, no extra
7158 code will be generated at the entry & exit (function prologue
7161 \begin_inset LatexCommand \index{function prologue}
7170 \begin_inset LatexCommand \index{function epilogue}
7176 ) for these functions to save & restore the registers used by these functions,
7177 this can SUBSTANTIALLY reduce code & improve run time performance of the
7179 In the future the compiler (with inter procedural analysis) will be able
7180 to determine the appropriate scheme to use for each function call.
7181 DO NOT use this option for built-in functions such as _mulint..., if this
7182 option is used for a library function the appropriate library function
7183 needs to be recompiled with the same option.
7184 If the project consists of multiple source files then all the source file
7185 should be compiled with the same -
7195 -callee-saves option string.
7196 Also see #pragma\SpecialChar ~
7198 \begin_inset LatexCommand \index{\#pragma callee\_saves}
7204 \labelwidthstring 00.00.0000
7219 \begin_inset LatexCommand \index{-\/-debug}
7228 When this option is used the compiler will generate debug information.
7229 The debug information collected in a file with .cdb extension can be used
7231 For more information see documentation for SDCDB.
7232 Another file with no extension contains debug information in AOMF or AOMF51
7233 \begin_inset LatexCommand \index{AOMF, AOMF51}
7237 format which is commonly used by third party tools.
7239 \labelwidthstring 00.00.0000
7244 \begin_inset LatexCommand \index{-S}
7255 Stop after the stage of compilation proper; do not assemble.
7256 The output is an assembler code file for the input file specified.
7258 \labelwidthstring 00.00.0000
7273 \begin_inset LatexCommand \index{-\/-int-long-reent}
7279 Integer (16 bit) and long (32 bit) libraries have been compiled as reentrant.
7280 Note by default these libraries are compiled as non-reentrant.
7281 See section Installation for more details.
7283 \labelwidthstring 00.00.0000
7298 \begin_inset LatexCommand \index{-\/-cyclomatic}
7307 This option will cause the compiler to generate an information message for
7308 each function in the source file.
7309 The message contains some
7313 information about the function.
7314 The number of edges and nodes the compiler detected in the control flow
7315 graph of the function, and most importantly the
7317 cyclomatic complexity
7318 \begin_inset LatexCommand \index{Cyclomatic complexity}
7324 see section on Cyclomatic Complexity for more details.
7326 \labelwidthstring 00.00.0000
7341 \begin_inset LatexCommand \index{-\/-float-reent}
7347 Floating point library is compiled as reentrant
7348 \begin_inset LatexCommand \index{reentrant}
7353 See section Installation for more details.
7355 \labelwidthstring 00.00.0000
7370 \begin_inset LatexCommand \index{-\/-main-return}
7376 This option can be used if the code generated is called by a monitor program
7377 or if the main routine includes an endless loop.
7378 This option might result in slightly smaller code and save two bytes of
7380 The return from the 'main'
7381 \begin_inset LatexCommand \index{main return}
7385 function will return to the function calling main.
7386 The default setting is to lock up i.e.
7393 \labelwidthstring 00.00.0000
7408 \begin_inset LatexCommand \index{-\/-nostdinc}
7414 This will prevent the compiler from passing on the default include path
7415 to the preprocessor.
7417 \labelwidthstring 00.00.0000
7432 \begin_inset LatexCommand \index{-\/-nostdlib}
7438 This will prevent the compiler from passing on the default library
7439 \begin_inset LatexCommand \index{Libraries}
7445 \labelwidthstring 00.00.0000
7460 \begin_inset LatexCommand \index{-\/-verbose}
7466 Shows the various actions the compiler is performing.
7468 \labelwidthstring 00.00.0000
7473 \begin_inset LatexCommand \index{-V}
7479 Shows the actual commands the compiler is executing.
7481 \labelwidthstring 00.00.0000
7496 \begin_inset LatexCommand \index{-\/-no-c-code-in-asm}
7502 Hides your ugly and inefficient c-code from the asm file, so you can always
7503 blame the compiler :)
7505 \labelwidthstring 00.00.0000
7520 \begin_inset LatexCommand \index{-\/-no-peep-comments}
7526 Will not include peep-hole comments in the generated files.
7528 \labelwidthstring 00.00.0000
7543 \begin_inset LatexCommand \index{-\/-i-code-in-asm}
7549 Include i-codes in the asm file.
7550 Sounds like noise but is most helpful for debugging the compiler itself.
7552 \labelwidthstring 00.00.0000
7567 \begin_inset LatexCommand \index{-\/-less-pedantic}
7573 Disable some of the more pedantic warnings
7574 \begin_inset LatexCommand \index{Warnings}
7578 (jwk burps: please be more specific here, please!).
7580 \labelwidthstring 00.00.0000
7594 -disable-warning\SpecialChar ~
7596 \begin_inset LatexCommand \index{-\/-disable-warning}
7602 Disable specific warning with number <nnnn>.
7604 \labelwidthstring 00.00.0000
7619 \begin_inset LatexCommand \index{-\/-print-search-dirs}
7625 Display the directories in the compiler's search path
7627 \labelwidthstring 00.00.0000
7642 \begin_inset LatexCommand \index{-\/-vc}
7648 Display errors and warnings using MSVC style, so you can use SDCC with
7651 \labelwidthstring 00.00.0000
7666 \begin_inset LatexCommand \index{-\/-use-stdout}
7672 Send errors and warnings to stdout instead of stderr.
7674 \labelwidthstring 00.00.0000
7679 asmOption[,asmOption]
7682 \begin_inset LatexCommand \index{-Wa asmOption[,asmOption]}
7687 Pass the asmOption to the assembler
7688 \begin_inset LatexCommand \index{Options assembler}
7693 \begin_inset LatexCommand \index{Assembler options}
7698 See file sdcc/as/doc/asxhtm.html for assembler options.cd
7700 \labelwidthstring 00.00.0000
7715 \begin_inset LatexCommand \index{-\/-std-sdcc89}
7721 Generally follow the C89 standard, but allow SDCC features that conflict
7722 with the standard (default).
7724 \labelwidthstring 00.00.0000
7739 \begin_inset LatexCommand \index{-\/-std-c89}
7745 Follow the C89 standard and disable SDCC features that conflict with the
7748 \labelwidthstring 00.00.0000
7763 \begin_inset LatexCommand \index{-\/-std-sdcc99}
7769 Generally follow the C99 standard, but allow SDCC features that conflict
7770 with the standard (incomplete support).
7772 \labelwidthstring 00.00.0000
7787 \begin_inset LatexCommand \index{-\/-std-sdcc99}
7793 Follow the C99 standard and disable SDCC features that conflict with the
7794 standard (incomplete support).
7796 \labelwidthstring 00.00.0000
7808 a SDCC compiler option but if you want
7812 warnings you can use a separate tool dedicated to syntax checking like
7814 \begin_inset LatexCommand \label{lyx:more-pedantic-SPLINT}
7819 \begin_inset LatexCommand \index{lint (syntax checking tool)}
7824 \begin_inset LatexCommand \url{http://www.splint.org}
7829 To make your source files parseable by splint you will have to include
7835 \begin_inset LatexCommand \index{splint (syntax checking tool)}
7839 in your source file and add brackets around extended keywords (like
7842 \begin_inset Quotes sld
7855 \begin_inset Quotes srd
7863 \begin_inset Quotes sld
7866 __interrupt\SpecialChar ~
7868 \begin_inset Quotes srd
7876 Splint has an excellent on line manual at
7877 \begin_inset LatexCommand \url{http://www.splint.org/manual/}
7881 and it's capabilities go beyond pure syntax checking.
7882 You'll need to tell splint the location of SDCC's include files so a typical
7883 command line could look like this:
7887 splint\SpecialChar ~
7889 /usr/local/share/sdcc/include/mcs51/\SpecialChar ~
7894 Intermediate Dump Options
7895 \begin_inset LatexCommand \label{sub:Intermediate-Dump-Options}
7900 \begin_inset LatexCommand \index{Options intermediate dump}
7905 \begin_inset LatexCommand \index{Intermediate dump options}
7912 The following options are provided for the purpose of retargetting and debugging
7914 They provide a means to dump the intermediate code (iCode
7915 \begin_inset LatexCommand \index{iCode}
7919 ) generated by the compiler in human readable form at various stages of
7920 the compilation process.
7921 More on iCodes see chapter
7922 \begin_inset LatexCommand \ref{sub:The-anatomy-of}
7927 \begin_inset Quotes srd
7930 The anatomy of the compiler
7931 \begin_inset Quotes srd
7936 \labelwidthstring 00.00.0000
7951 \begin_inset LatexCommand \index{-\/-dumpraw}
7957 This option will cause the compiler to dump the intermediate code into
7960 <source filename>.dumpraw
7962 just after the intermediate code has been generated for a function, i.e.
7963 before any optimizations are done.
7965 \begin_inset LatexCommand \index{Basic blocks}
7969 at this stage ordered in the depth first number, so they may not be in
7970 sequence of execution.
7972 \labelwidthstring 00.00.0000
7987 \begin_inset LatexCommand \index{-\/-dumpgcse}
7993 Will create a dump of iCode's, after global subexpression elimination
7994 \begin_inset LatexCommand \index{Global subexpression elimination}
8000 <source filename>.dumpgcse.
8002 \labelwidthstring 00.00.0000
8017 \begin_inset LatexCommand \index{-\/-dumpdeadcode}
8023 Will create a dump of iCode's, after deadcode elimination
8024 \begin_inset LatexCommand \index{Dead-code elimination}
8030 <source filename>.dumpdeadcode.
8032 \labelwidthstring 00.00.0000
8047 \begin_inset LatexCommand \index{-\/-dumploop}
8056 Will create a dump of iCode's, after loop optimizations
8057 \begin_inset LatexCommand \index{Loop optimization}
8063 <source filename>.dumploop.
8065 \labelwidthstring 00.00.0000
8080 \begin_inset LatexCommand \index{-\/-dumprange}
8089 Will create a dump of iCode's, after live range analysis
8090 \begin_inset LatexCommand \index{Live range analysis}
8096 <source filename>.dumprange.
8098 \labelwidthstring 00.00.0000
8113 \begin_inset LatexCommand \index{-\/-dumlrange}
8119 Will dump the life ranges
8120 \begin_inset LatexCommand \index{Live range analysis}
8126 \labelwidthstring 00.00.0000
8141 \begin_inset LatexCommand \index{-\/-dumpregassign}
8150 Will create a dump of iCode's, after register assignment
8151 \begin_inset LatexCommand \index{Register assignment}
8157 <source filename>.dumprassgn.
8159 \labelwidthstring 00.00.0000
8174 \begin_inset LatexCommand \index{-\/-dumplrange}
8180 Will create a dump of the live ranges of iTemp's
8182 \labelwidthstring 00.00.0000
8197 \begin_inset LatexCommand \index{-\/-dumpall}
8208 Will cause all the above mentioned dumps to be created.
8211 Redirecting output on Windows Shells
8214 By default SDCC writes it's error messages to
8215 \begin_inset Quotes sld
8219 \begin_inset Quotes srd
8223 To force all messages to
8224 \begin_inset Quotes sld
8228 \begin_inset Quotes srd
8252 \begin_inset LatexCommand \index{-\/-use-stdout}
8257 Additionally, if you happen to have visual studio installed in your windows
8258 machine, you can use it to compile your sources using a custom build and
8274 \begin_inset LatexCommand \index{-\/-vc}
8279 Something like this should work:
8323 -model-large -c $(InputPath)
8326 Environment variables
8327 \begin_inset LatexCommand \index{Environment variables}
8334 SDCC recognizes the following environment variables:
8336 \labelwidthstring 00.00.0000
8341 \begin_inset LatexCommand \index{SDCC\_LEAVE\_SIGNALS}
8347 SDCC installs a signal handler
8348 \begin_inset LatexCommand \index{signal handler}
8352 to be able to delete temporary files after an user break (^C) or an exception.
8353 If this environment variable is set, SDCC won't install the signal handler
8354 in order to be able to debug SDCC.
8356 \labelwidthstring 00.00.0000
8363 \begin_inset LatexCommand \index{TMP, TEMP, TMPDIR}
8369 Path, where temporary files will be created.
8370 The order of the variables is the search order.
8371 In a standard *nix environment these variables are not set, and there's
8372 no need to set them.
8373 On Windows it's recommended to set one of them.
8375 \labelwidthstring 00.00.0000
8380 \begin_inset LatexCommand \index{SDCC\_HOME}
8387 \begin_inset LatexCommand \ref{sub:Install-paths}
8393 \begin_inset Quotes sld
8397 \begin_inset Quotes srd
8402 \labelwidthstring 00.00.0000
8407 \begin_inset LatexCommand \index{SDCC\_INCLUDE}
8414 \begin_inset LatexCommand \ref{sub:Search-Paths}
8420 \begin_inset Quotes sld
8424 \begin_inset Quotes srd
8429 \labelwidthstring 00.00.0000
8434 \begin_inset LatexCommand \index{SDCC\_LIB}
8441 \begin_inset LatexCommand \ref{sub:Search-Paths}
8447 \begin_inset Quotes sld
8451 \begin_inset Quotes srd
8457 There are some more environment variables recognized by SDCC, but these
8458 are solely used for debugging purposes.
8459 They can change or disappear very quickly, and will never be documented.
8462 Storage Class Language Extensions
8465 MCS51/DS390 Storage Class
8466 \begin_inset LatexCommand \index{Storage class}
8473 In addition to the ANSI storage classes SDCC allows the following MCS51
8474 specific storage classes:
8475 \layout Subsubsection
8478 \begin_inset LatexCommand \index{data (mcs51, ds390 storage class)}
8483 \begin_inset LatexCommand \index{\_\_data (mcs51, ds390 storage class)}
8488 \begin_inset LatexCommand \index{near (storage class)}
8493 \begin_inset LatexCommand \index{\_\_near (storage class)}
8504 storage class for the Small Memory model (
8512 can be used synonymously).
8513 Variables declared with this storage class will be allocated in the directly
8514 addressable portion of the internal RAM of a 8051, e.g.:
8519 data unsigned char test_data;
8522 Writing 0x01 to this variable generates the assembly code:
8527 75*00 01\SpecialChar ~
8533 \layout Subsubsection
8536 \begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
8541 \begin_inset LatexCommand \index{\_\_xdata (mcs51, ds390 storage class)}
8546 \begin_inset LatexCommand \index{far (storage class)}
8551 \begin_inset LatexCommand \index{\_\_far (storage class)}
8558 Variables declared with this storage class will be placed in the external
8564 storage class for the Large Memory model, e.g.:
8569 xdata unsigned char test_xdata;
8572 Writing 0x01 to this variable generates the assembly code:
8577 90s00r00\SpecialChar ~
8606 \layout Subsubsection
8609 \begin_inset LatexCommand \index{idata (mcs51, ds390 storage class)}
8614 \begin_inset LatexCommand \index{\_\_idata (mcs51, ds390 storage class)}
8621 Variables declared with this storage class will be allocated into the indirectly
8622 addressable portion of the internal ram of a 8051, e.g.:
8627 idata unsigned char test_idata;
8630 Writing 0x01 to this variable generates the assembly code:
8659 Please note, the first 128 byte of idata physically access the same RAM
8661 The original 8051 had 128 byte idata memory, nowadays most devices have
8662 256 byte idata memory.
8664 \begin_inset LatexCommand \index{stack}
8668 is located in idata memory.
8669 \layout Subsubsection
8672 \begin_inset LatexCommand \index{pdata (mcs51, ds390 storage class)}
8677 \begin_inset LatexCommand \index{\_\_pdata (mcs51, ds390 storage class)}
8684 Paged xdata access is just as straightforward as using the other addressing
8686 It is typically located at the start of xdata and has a maximum size of
8688 The following example writes 0x01 to the pdata variable.
8689 Please note, pdata access physically accesses xdata memory.
8690 The high byte of the address is determined by port P2
8691 \begin_inset LatexCommand \index{P2 (mcs51 sfr)}
8695 (or in case of some 8051 variants by a separate Special Function Register,
8697 \begin_inset LatexCommand \ref{sub:MCS51-variants}
8706 pdata unsigned char test_pdata;
8709 Writing 0x01 to this variable generates the assembly code:
8753 \begin_inset LatexCommand \index{-\/-xstack}
8757 option is used the pdata memory area is followed by the xstack memory area
8758 and the sum of their sizes is limited to 256 bytes.
8759 \layout Subsubsection
8762 \begin_inset LatexCommand \index{code}
8767 \begin_inset LatexCommand \index{\_\_code}
8774 'Variables' declared with this storage class will be placed in the code
8780 code unsigned char test_code;
8783 Read access to this variable generates the assembly code:
8788 90s00r6F\SpecialChar ~
8791 mov dptr,#_test_code
8820 indexed arrays of characters in code memory can be accessed efficiently:
8825 code char test_array[] = {'c','h','e','a','p'};
8828 Read access to this array using an 8-bit unsigned index generates the assembly
8845 90s00r41\SpecialChar ~
8848 mov dptr,#_test_array
8863 \layout Subsubsection
8866 \begin_inset LatexCommand \index{bit}
8871 \begin_inset LatexCommand \index{\_\_bit}
8878 This is a data-type and a storage class specifier.
8879 When a variable is declared as a bit, it is allocated into the bit addressable
8880 memory of 8051, e.g.:
8888 Writing 1 to this variable generates the assembly code:
8904 The bit addressable memory consists of 128 bits which are located from 0x20
8905 to 0x2f in data memory.
8908 Apart from this 8051 specific storage class most architectures support ANSI-C
8910 \begin_inset LatexCommand \index{bitfields}
8920 Not really meant as examples, but nevertheless showing what bitfields are
8921 about: device/include/mc68hc908qy.h and support/regression/tests/bitfields.c
8925 In accordance with ISO/IEC 9899 bits and bitfields without an explicit
8926 signed modifier are implemented as unsigned.
8927 \layout Subsubsection
8930 \begin_inset LatexCommand \index{sfr}
8935 \begin_inset LatexCommand \index{\_\_sfr}
8940 \begin_inset LatexCommand \index{sfr16}
8945 \begin_inset LatexCommand \index{\_\_sfr16}
8950 \begin_inset LatexCommand \index{sfr32}
8955 \begin_inset LatexCommand \index{\_\_sfr32}
8960 \begin_inset LatexCommand \index{\_\_sbit}
8967 Like the bit keyword,
8969 sfr / sfr16 / sfr32 / sbit
8971 signify both a data-type and storage class, they are used to describe the
8992 variables of a 8051, eg:
8998 \begin_inset LatexCommand \index{at}
9003 \begin_inset LatexCommand \index{\_\_at}
9007 0x80 P0;\SpecialChar ~
9008 /* special function register P0 at location 0x80 */
9010 /* 16 bit special function register combination for timer 0 */
9012 /* with the high byte at location 0x8C and the low byte at location 0x8A
9016 \begin_inset LatexCommand \index{at}
9021 \begin_inset LatexCommand \index{\_\_at}
9027 sbit at 0xd7 CY; /* CY (Carry Flag
9028 \begin_inset LatexCommand \index{Flags}
9033 \begin_inset LatexCommand \index{Carry flag}
9040 Special function registers which are located on an address dividable by
9041 8 are bit-addressable, an
9045 addresses a specific bit within these sfr.
9047 16 Bit and 32 bit special function register combinations which require a
9048 certain access order are better not declared using
9057 Allthough SDCC usually accesses them Least Significant Byte (LSB) first,
9058 this is not guaranteed.
9059 \layout Subsubsection
9062 \begin_inset LatexCommand \index{Pointer}
9066 to MCS51/DS390 specific memory spaces
9069 SDCC allows (via language extensions) pointers to explicitly point to any
9070 of the memory spaces
9071 \begin_inset LatexCommand \index{Memory model}
9076 In addition to the explicit pointers, the compiler uses (by default) generic
9077 pointers which can be used to point to any of the memory spaces.
9081 Pointer declaration examples:
9086 /* pointer physically in internal ram pointing to object in external ram
9089 xdata unsigned char * data p;
9093 /* pointer physically in external ram pointing to object in internal ram
9096 data unsigned char * xdata p;
9100 /* pointer physically in code rom pointing to data in xdata space */
9102 xdata unsigned char * code p;
9106 /* pointer physically in code space pointing to data in code space */
9108 code unsigned char * code p;
9112 /* the following is a generic pointer physically located in xdata space
9119 /* the following is a function pointer physically located in data space
9122 char (* data fp)(void);
9125 Well you get the idea.
9130 All unqualified pointers are treated as 3-byte (4-byte for the ds390)
9143 The highest order byte of the
9147 pointers contains the data space information.
9148 Assembler support routines are called whenever data is stored or retrieved
9154 These are useful for developing reusable library
9155 \begin_inset LatexCommand \index{Libraries}
9160 Explicitly specifying the pointer type will generate the most efficient
9162 \layout Subsubsection
9164 Notes on MCS51 memory
9165 \begin_inset LatexCommand \index{MCS51 memory}
9172 The 8051 family of microcontrollers have a minimum of 128 bytes of internal
9173 RAM memory which is structured as follows:
9177 - Bytes 00-1F - 32 bytes to hold up to 4 banks of the registers R0 to R7,
9180 - Bytes 20-2F - 16 bytes to hold 128 bit
9181 \begin_inset LatexCommand \index{bit}
9187 - Bytes 30-7F - 80 bytes for general purpose use.
9192 Additionally some members of the MCS51 family may have up to 128 bytes of
9193 additional, indirectly addressable, internal RAM memory (
9198 \begin_inset LatexCommand \index{idata (mcs51, ds390 storage class)}
9203 \begin_inset LatexCommand \index{\_\_idata (mcs51, ds390 storage class)}
9208 Furthermore, some chips may have some built in external memory (
9213 \begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
9218 \begin_inset LatexCommand \index{\_\_xdata (mcs51, ds390 storage class)}
9222 ) which should not be confused with the internal, directly addressable RAM
9228 \begin_inset LatexCommand \index{data (mcs51, ds390 storage class)}
9233 \begin_inset LatexCommand \index{\_\_data (mcs51, ds390 storage class)}
9238 Sometimes this built in
9242 memory has to be activated before using it (you can probably find this
9243 information on the datasheet of the microcontroller your are using, see
9245 \begin_inset LatexCommand \ref{sub:Startup-Code}
9253 Normally SDCC will only use the first bank
9254 \begin_inset LatexCommand \index{register bank (mcs51, ds390)}
9258 of registers (register bank 0), but it is possible to specify that other
9259 banks of registers (keyword
9266 \begin_inset LatexCommand \index{using (mcs51, ds390 register bank)}
9271 \begin_inset LatexCommand \index{\_\_using (mcs51, ds390 register bank)}
9277 ) should be used in interrupt
9278 \begin_inset LatexCommand \index{interrupt}
9283 \begin_inset LatexCommand \index{\_\_interrupt}
9288 By default, the compiler will place the stack after the last byte of allocated
9289 memory for variables.
9290 For example, if the first 2 banks of registers are used, and only four
9295 variables, it will position the base of the internal stack at address 20
9297 This implies that as the stack
9298 \begin_inset LatexCommand \index{stack}
9302 grows, it will use up the remaining register banks, and the 16 bytes used
9303 by the 128 bit variables, and 80 bytes for general purpose use.
9304 If any bit variables are used, the data variables will be placed in unused
9305 register banks and after the byte holding the last bit variable.
9306 For example, if register banks 0 and 1 are used, and there are 9 bit variables
9311 variables will be placed starting from address 0x10 to 0x20 and continue
9324 \begin_inset LatexCommand \index{-\/-data-loc <Value>}
9328 to specify the start address of the
9343 \begin_inset LatexCommand \index{-\/-iram-size <Value>}
9347 to specify the size of the total internal RAM (
9359 By default the 8051 linker will place the stack after the last byte of (i)data
9372 \begin_inset LatexCommand \index{-\/-stack-loc <Value>}
9376 allows you to specify the start of the stack, i.e.
9377 you could start it after any data in the general purpose area.
9378 If your microcontroller has additional indirectly addressable internal
9383 ) you can place the stack on it.
9384 You may also need to use -
9395 \begin_inset LatexCommand \index{-\/-xdata-loc<Value>}
9399 to set the start address of the external RAM (
9414 \begin_inset LatexCommand \index{-\/-xram-size <Value>}
9418 to specify its size.
9419 Same goes for the code memory, using -
9430 \begin_inset LatexCommand \index{-\/-code-loc <Value>}
9445 \begin_inset LatexCommand \index{-\/-code-size <Value>}
9450 If in doubt, don't specify any options and see if the resulting memory
9451 layout is appropriate, then you can adjust it.
9454 The linker generates two files with memory allocation information.
9455 The first, with extension .map
9456 \begin_inset LatexCommand \index{<file>.map}
9460 shows all the variables and segments.
9461 The second with extension .mem
9462 \begin_inset LatexCommand \index{<file>.mem}
9466 shows the final memory layout.
9467 The linker will complain either if memory segments overlap, there is not
9468 enough memory, or there is not enough space for stack.
9469 If you get any linking warnings and/or errors related to stack or segments
9470 allocation, take a look at either the .map or .mem files to find out what
9472 The .mem file may even suggest a solution to the problem.
9475 Z80/Z180 Storage Class
9476 \begin_inset LatexCommand \index{Storage class}
9481 \layout Subsubsection
9484 \begin_inset LatexCommand \index{sfr}
9489 \begin_inset LatexCommand \index{\_\_sfr}
9493 (in/out to 8-bit addresses)
9497 \begin_inset LatexCommand \index{Z80}
9501 family has separate address spaces for memory and
9511 \begin_inset LatexCommand \index{I/O memory (Z80, Z180)}
9515 is accessed with special instructions, e.g.:
9520 sfr at 0x78 IoPort;\SpecialChar ~
9522 /* define a var in I/O space at 78h called IoPort */
9526 Writing 0x01 to this variable generates the assembly code:
9546 \layout Subsubsection
9549 \begin_inset LatexCommand \index{sfr}
9554 \begin_inset LatexCommand \index{\_\_sfr}
9558 (in/out to 16-bit addresses)
9565 is used to support 16 bit addresses in I/O memory e.g.:
9571 \begin_inset LatexCommand \index{at}
9576 \begin_inset LatexCommand \index{\_\_at}
9583 Writing 0x01 to this variable generates the assembly code:
9588 01 23 01\SpecialChar ~
9608 \layout Subsubsection
9611 \begin_inset LatexCommand \index{sfr}
9616 \begin_inset LatexCommand \index{\_\_sfr}
9620 (in0/out0 to 8 bit addresses on Z180
9621 \begin_inset LatexCommand \index{Z180}
9626 \begin_inset LatexCommand \index{HD64180}
9633 The compiler option -
9643 -portmode=180 (80) and a compiler #pragma\SpecialChar ~
9645 \begin_inset LatexCommand \index{\#pragma portmode}
9649 =z180 (z80) is used to turn on (off) the Z180/HD64180 port addressing instructio
9659 If you include the file z180.h this will be set automatically.
9663 \begin_inset LatexCommand \index{Storage class}
9668 \layout Subsubsection
9671 \begin_inset LatexCommand \index{data (hc08 storage class)}
9676 \begin_inset LatexCommand \index{\_\_data (hc08 storage class)}
9683 The data storage class declares a variable that resides in the first 256
9684 bytes of memory (the direct page).
9685 The HC08 is most efficient at accessing variables (especially pointers)
9687 \layout Subsubsection
9690 \begin_inset LatexCommand \index{xdata (hc08 storage class)}
9695 \begin_inset LatexCommand \index{\_\_xdata (hc08 storage class)}
9702 The xdata storage class declares a variable that can reside anywhere in
9704 This is the default if no storage class is specified.
9709 \begin_inset LatexCommand \index{Absolute addressing}
9716 Data items can be assigned an absolute address with the
9719 \begin_inset LatexCommand \index{at}
9724 \begin_inset LatexCommand \index{\_\_at}
9730 keyword, in addition to a storage class, e.g.:
9736 \begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
9741 \begin_inset LatexCommand \index{\_\_xdata (mcs51, ds390 storage class)}
9746 \begin_inset LatexCommand \index{at}
9751 \begin_inset LatexCommand \index{\_\_at}
9755 0x7ffe unsigned int chksum;
9758 In the above example the variable chksum will be located at 0x7ffe and 0x7fff
9759 of the external ram.
9764 reserve any space for variables declared in this way (they are implemented
9765 with an equate in the assembler).
9766 Thus it is left to the programmer to make sure there are no overlaps with
9767 other variables that are declared without the absolute address.
9768 The assembler listing file (.lst
9769 \begin_inset LatexCommand \index{<file>.lst}
9773 ) and the linker output files (.rst
9774 \begin_inset LatexCommand \index{<file>.rst}
9779 \begin_inset LatexCommand \index{<file>.map}
9783 ) are good places to look for such overlaps.
9784 Variables with an absolute address are
9789 \begin_inset LatexCommand \index{Variable initialization}
9796 In case of memory mapped I/O devices the keyword
9800 has to be used to tell the compiler that accesses might not be removed:
9806 \begin_inset LatexCommand \index{volatile}
9811 \begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
9816 \begin_inset LatexCommand \index{at}
9820 0x8000 unsigned char PORTA_8255;
9823 For some architectures (mcs51) array accesses are more efficient if an (xdata/fa
9828 \begin_inset LatexCommand \index{Aligned array}
9835 starts at a block (256 byte) boundary
9836 \begin_inset LatexCommand \index{block boundary}
9841 \begin_inset LatexCommand \ref{sub:A-Step-by Assembler Introduction}
9847 Absolute addresses can be specified for variables in all storage classes,
9854 \begin_inset LatexCommand \index{bit}
9859 \begin_inset LatexCommand \index{at}
9866 The above example will allocate the variable at offset 0x02 in the bit-addressab
9868 There is no real advantage to assigning absolute addresses to variables
9869 in this manner, unless you want strict control over all the variables allocated.
9870 One possible use would be to write hardware portable code.
9871 For example, if you have a routine that uses one or more of the microcontroller
9872 I/O pins, and such pins are different for two different hardwares, you
9873 can declare the I/O pins in your routine using:
9879 \begin_inset LatexCommand \index{volatile}
9883 bit MOSI;\SpecialChar ~
9887 /* master out, slave in */
9889 extern volatile bit MISO;\SpecialChar ~
9893 /* master in, slave out */
9895 extern volatile bit MCLK;\SpecialChar ~
9903 /* Input and Output of a byte on a 3-wire serial bus.
9908 If needed adapt polarity of clock, polarity of data and bit order
9913 unsigned char spi_io(unsigned char out_byte)
9937 MOSI = out_byte & 0x80;
9967 /* _asm nop _endasm; */\SpecialChar ~
9975 /* for slow peripherals */
10026 Then, someplace in the code for the first hardware you would use
10032 \begin_inset LatexCommand \index{at}
10037 \begin_inset LatexCommand \index{\_\_at}
10041 0x80 MOSI;\SpecialChar ~
10045 /* I/O port 0, bit 0 */
10047 bit at 0x81 MISO;\SpecialChar ~
10051 /* I/O port 0, bit 1 */
10053 bit at 0x82 MCLK;\SpecialChar ~
10057 /* I/O port 0, bit 2 */
10060 Similarly, for the second hardware you would use
10065 bit at 0x83 MOSI;\SpecialChar ~
10069 /* I/O port 0, bit 3 */
10071 bit at 0x91 MISO;\SpecialChar ~
10075 /* I/O port 1, bit 1 */
10078 \begin_inset LatexCommand \index{bit}
10082 at 0x92 MCLK;\SpecialChar ~
10086 /* I/O port 1, bit 2 */
10089 and you can use the same hardware dependent routine without changes, as
10090 for example in a library.
10091 This is somehow similar to sbit, but only one absolute address has to be
10092 specified in the whole project.
10096 \begin_inset LatexCommand \index{Parameters}
10101 \begin_inset LatexCommand \index{function parameter}
10106 \begin_inset LatexCommand \index{local variables}
10111 \begin_inset LatexCommand \label{sec:Parameters-and-Local-Variables}
10118 Automatic (local) variables and parameters to functions can either be placed
10119 on the stack or in data-space.
10120 The default action of the compiler is to place these variables in the internal
10121 RAM (for small model) or external RAM (for large model).
10122 This in fact makes them similar to
10125 \begin_inset LatexCommand \index{static}
10131 so by default functions are non-reentrant
10132 \begin_inset LatexCommand \index{reentrant}
10141 They can be placed on the stack
10142 \begin_inset LatexCommand \index{stack}
10159 \begin_inset LatexCommand \index{-\/-stack-auto}
10167 #pragma\SpecialChar ~
10171 \begin_inset LatexCommand \index{\#pragma stackauto}
10178 \begin_inset LatexCommand \index{reentrant}
10184 keyword in the function declaration, e.g.:
10189 unsigned char foo(char i) reentrant
10203 Since stack space on 8051 is limited, the
10221 option should be used sparingly.
10222 Note that the reentrant keyword just means that the parameters & local
10223 variables will be allocated to the stack, it
10227 mean that the function is register bank
10228 \begin_inset LatexCommand \index{register bank (mcs51, ds390)}
10237 \begin_inset LatexCommand \index{local variables}
10241 can be assigned storage classes and absolute
10242 \begin_inset LatexCommand \index{Absolute addressing}
10251 unsigned char foo()
10259 xdata unsigned char i;
10272 \begin_inset LatexCommand \index{at}
10276 0x31 unsigned char j;
10288 In the above example the variable
10292 will be allocated in the external ram,
10296 in bit addressable space and
10315 or when a function is declared as
10319 this should only be done for static variables.
10323 \begin_inset LatexCommand \index{function parameter}
10327 however are not allowed any storage class
10328 \begin_inset LatexCommand \index{Storage class}
10332 , (storage classes for parameters will be ignored), their allocation is
10333 governed by the memory model in use, and the reentrancy options.
10337 \begin_inset LatexCommand \label{sub:Overlaying}
10342 \begin_inset LatexCommand \index{Overlaying}
10350 \begin_inset LatexCommand \index{reentrant}
10354 functions SDCC will try to reduce internal ram space usage by overlaying
10355 parameters and local variables of a function (if possible).
10356 Parameters and local variables
10357 \begin_inset LatexCommand \index{local variables}
10361 of a function will be allocated to an overlayable segment if the function
10364 no other function calls and the function is non-reentrant and the memory
10366 \begin_inset LatexCommand \index{Memory model}
10373 If an explicit storage class
10374 \begin_inset LatexCommand \index{Storage class}
10378 is specified for a local variable, it will NOT be overlayed.
10381 Note that the compiler (not the linkage editor) makes the decision for overlayin
10383 Functions that are called from an interrupt service routine should be preceded
10384 by a #pragma\SpecialChar ~
10386 \begin_inset LatexCommand \index{\#pragma nooverlay}
10390 if they are not reentrant.
10393 Also note that the compiler does not do any processing of inline assembler
10394 code, so the compiler might incorrectly assign local variables and parameters
10395 of a function into the overlay segment if the inline assembler code calls
10396 other c-functions that might use the overlay.
10397 In that case the #pragma\SpecialChar ~
10398 nooverlay should be used.
10401 Parameters and local variables of functions that contain 16 or 32 bit multiplica
10403 \begin_inset LatexCommand \index{Multiplication}
10408 \begin_inset LatexCommand \index{Division}
10412 will NOT be overlayed since these are implemented using external functions,
10421 \begin_inset LatexCommand \index{\#pragma nooverlay}
10427 void set_error(unsigned char errcd)
10443 void some_isr () interrupt
10444 \begin_inset LatexCommand \index{interrupt}
10474 In the above example the parameter
10482 would be assigned to the overlayable segment if the #pragma\SpecialChar ~
10484 not present, this could cause unpredictable runtime behavior when called
10485 from an interrupt service routine.
10486 The #pragma\SpecialChar ~
10487 nooverlay ensures that the parameters and local variables for
10488 the function are NOT overlayed.
10491 Interrupt Service Routines
10492 \begin_inset LatexCommand \label{sub:Interrupt-Service-Routines}
10499 General Information
10514 outines to be coded in C, with some extended keywords.
10519 void timer_isr (void) interrupt 1 using 1
10533 The optional number following the
10536 \begin_inset LatexCommand \index{interrupt}
10541 \begin_inset LatexCommand \index{\_\_interrupt}
10547 keyword is the interrupt number this routine will service.
10548 When present, the compiler will insert a call to this routine in the interrupt
10549 vector table for the interrupt number specified.
10550 If you have multiple source files in your project, interrupt service routines
10551 can be present in any of them, but a prototype of the isr MUST be present
10552 or included in the file that contains the function
10560 \begin_inset LatexCommand \index{using (mcs51, ds390 register bank)}
10565 \begin_inset LatexCommand \index{\_\_using (mcs51, ds390 register bank)}
10571 keyword can be used to tell the compiler to use the specified register
10572 bank (8051 specific) when generating code for this function.
10578 Interrupt service routines open the door for some very interesting bugs:
10580 If an interrupt service routine changes variables which are accessed by
10581 other functions these variables have to be declared
10586 \begin_inset LatexCommand \index{volatile}
10594 If the access to these variables is not
10597 \begin_inset LatexCommand \index{atomic}
10604 the processor needs more than one instruction for the access and could
10605 be interrupted while accessing the variable) the interrupt must be disabled
10606 during the access to avoid inconsistent data.
10607 Access to 16 or 32 bit variables is obviously not atomic on 8 bit CPUs
10608 and should be protected by disabling interrupts.
10609 You're not automatically on the safe side if you use 8 bit variables though.
10610 We need an example here: f.e.
10611 on the 8051 the harmless looking
10612 \begin_inset Quotes srd
10617 flags\SpecialChar ~
10622 \begin_inset Quotes sld
10631 \begin_inset Quotes srd
10636 flags\SpecialChar ~
10641 \begin_inset Quotes sld
10644 from within an interrupt routine might get lost if the interrupt occurs
10647 \begin_inset Quotes sld
10652 counter\SpecialChar ~
10657 \begin_inset Quotes srd
10660 is not atomic on the 8051 even if
10664 is located in data memory.
10665 Bugs like these are hard to reproduce and can cause a lot of trouble.
10669 The return address and the registers used in the interrupt service routine
10670 are saved on the stack
10671 \begin_inset LatexCommand \index{stack}
10675 so there must be sufficient stack space.
10676 If there isn't variables or registers (or even the return address itself)
10683 \begin_inset LatexCommand \index{stack overflow}
10687 is most likely to happen if the interrupt occurs during the
10688 \begin_inset Quotes sld
10692 \begin_inset Quotes srd
10695 subroutine when the stack is already in use for f.e.
10696 many return addresses.
10699 A special note here, int (16 bit) and long (32 bit) integer division
10700 \begin_inset LatexCommand \index{Division}
10705 \begin_inset LatexCommand \index{Multiplication}
10710 \begin_inset LatexCommand \index{Modulus}
10715 \begin_inset LatexCommand \index{Floating point support}
10719 operations are implemented using external support routines developed in
10721 If an interrupt service routine needs to do any of these operations then
10722 the support routines (as mentioned in a following section) will have to
10723 be recompiled using the
10736 \begin_inset LatexCommand \index{-\/-stack-auto}
10742 option and the source file will need to be compiled using the
10757 \begin_inset LatexCommand \index{-\/-int-long-reent}
10764 Calling other functions from an interrupt service routine is not recommended,
10765 avoid it if possible.
10766 Note that when some function is called from an interrupt service routine
10767 it should be preceded by a #pragma\SpecialChar ~
10769 \begin_inset LatexCommand \index{\#pragma nooverlay}
10773 if it is not reentrant.
10774 Furthermore nonreentrant functions should not be called from the main program
10775 while the interrupt service routine might be active.
10781 \begin_inset LatexCommand \ref{sub:Overlaying}
10786 about Overlaying and section
10787 \begin_inset LatexCommand \ref{sub:Functions-using-private-banks}
10792 about Functions using private register banks.
10795 MCS51/DS390 Interrupt Service Routines
10798 Interrupt numbers and the corresponding address & descriptions for the Standard
10799 8051/8052 are listed below.
10800 SDCC will automatically adjust the interrupt vector table to the maximum
10801 interrupt number specified.
10807 \begin_inset Tabular
10808 <lyxtabular version="3" rows="7" columns="3">
10810 <column alignment="center" valignment="top" leftline="true" width="0in">
10811 <column alignment="center" valignment="top" leftline="true" width="0in">
10812 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0in">
10813 <row topline="true" bottomline="true">
10814 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
10822 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
10830 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
10839 <row topline="true">
10840 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
10848 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
10856 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
10865 <row topline="true">
10866 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
10874 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
10882 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
10891 <row topline="true">
10892 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
10900 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
10908 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
10917 <row topline="true">
10918 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
10926 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
10934 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
10943 <row topline="true">
10944 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
10952 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
10960 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
10969 <row topline="true" bottomline="true">
10970 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
10978 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
10986 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
11004 If the interrupt service routine is defined without
11007 \begin_inset LatexCommand \index{using (mcs51, ds390 register bank)}
11012 \begin_inset LatexCommand \index{\_\_using (mcs51, ds390 register bank)}
11018 a register bank or with register bank 0 (
11022 0), the compiler will save the registers used by itself on the stack upon
11023 entry and restore them at exit, however if such an interrupt service routine
11024 calls another function then the entire register bank will be saved on the
11026 This scheme may be advantageous for small interrupt service routines which
11027 have low register usage.
11030 If the interrupt service routine is defined to be using a specific register
11035 & psw are saved and restored, if such an interrupt service routine calls
11036 another function (using another register bank) then the entire register
11037 bank of the called function will be saved on the stack.
11038 This scheme is recommended for larger interrupt service routines.
11041 HC08 Interrupt Service Routines
11044 Since the number of interrupts available is chip specific and the interrupt
11045 vector table always ends at the last byte of memory, the interrupt numbers
11046 corresponds to the interrupt vectors in reverse order of address.
11047 For example, interrupt 1 will use the interrupt vector at 0xfffc, interrupt
11048 2 will use the interrupt vector at 0xfffa, and so on.
11049 However, interrupt 0 (the reset vector at 0xfffe) is not redefinable in
11050 this way; instead see section
11051 \begin_inset LatexCommand \ref{sub:Startup-Code}
11055 for details on customizing startup.
11058 Z80 Interrupt Service Routines
11061 The Z80 uses several different methods for determining the correct interrupt
11062 vector depending on the hardware implementation.
11063 Therefore, SDCC ignores the optional interrupt number and does not attempt
11064 to generate an interrupt vector table.
11067 By default, SDCC generates code for a maskable interrupt, which uses an
11068 RETI instruction to return from the interrupt.
11069 To write an interrupt handler for the non-maskable interrupt, which needs
11070 an RETN instruction instead, add the
11079 void nmi_isr (void) critical interrupt
11093 Enabling and Disabling Interrupts
11096 Critical Functions and Critical Statements
11099 A special keyword may be associated with a block or a function declaring
11105 SDCC will generate code to disable all interrupts
11106 \begin_inset LatexCommand \index{interrupt}
11110 upon entry to a critical function and restore the interrupt enable to the
11111 previous state before returning.
11112 Nesting critical functions will need one additional byte on the stack
11113 \begin_inset LatexCommand \index{stack}
11122 int foo () critical
11123 \begin_inset LatexCommand \index{critical}
11128 \begin_inset LatexCommand \index{\_\_critical}
11153 The critical attribute maybe used with other attributes like
11163 may also be used to disable interrupts more locally:
11171 More than one statement could have been included in the block.
11174 Enabling and Disabling Interrupts directly
11178 \begin_inset LatexCommand \index{interrupt}
11182 can also be disabled and enabled directly (8051):
11187 EA = 0;\SpecialChar ~
11250 EA = 1;\SpecialChar ~
11317 On other architectures which have seperate opcodes for enabling and disabling
11318 interrupts you might want to make use of defines with inline assembly
11319 \begin_inset LatexCommand \index{Assembler routines}
11329 \begin_inset LatexCommand \index{\_asm}
11338 \begin_inset LatexCommand \index{\_endasm}
11347 #define SEI _asm\SpecialChar ~
11359 Note: it is sometimes sufficient to disable only a specific interrupt source
11361 a timer or serial interrupt by manipulating an
11364 \begin_inset LatexCommand \index{interrupt mask}
11374 Usually the time during which interrupts are disabled should be kept as
11376 This minimizes both
11381 \begin_inset LatexCommand \index{interrupt latency}
11385 (the time between the occurrence of the interrupt and the execution of
11386 the first code in the interrupt routine) and
11391 \begin_inset LatexCommand \index{interrupt jitter}
11395 (the difference between the shortest and the longest interrupt latency).
11396 These really are something different, f.e.
11397 a serial interrupt has to be served before its buffer overruns so it cares
11398 for the maximum interrupt latency, whereas it does not care about jitter.
11399 On a loudspeaker driven via a digital to analog converter which is fed
11400 by an interrupt a latency of a few milliseconds might be tolerable, whereas
11401 a much smaller jitter will be very audible.
11404 You can reenable interrupts within an interrupt routine and on some architecture
11405 s you can make use of two (or more) levels of
11407 interrupt priorities
11410 \begin_inset LatexCommand \index{interrupt priority}
11415 On some architectures which don't support interrupt priorities these can
11416 be implemented by manipulating the interrupt mask and reenabling interrupts
11417 within the interrupt routine.
11418 Check there is sufficient space on the stack
11419 \begin_inset LatexCommand \index{stack}
11423 and don't add complexity unless you have to.
11428 \begin_inset LatexCommand \index{semaphore}
11432 locking (mcs51/ds390)
11435 Some architectures (mcs51/ds390) have an atomic
11436 \begin_inset LatexCommand \index{atomic}
11449 These type of instructions are typically used in preemptive multitasking
11450 systems, where a routine f.e.
11451 claims the use of a data structure ('acquires a lock
11452 \begin_inset LatexCommand \index{lock}
11456 on it'), makes some modifications and then releases the lock when the data
11457 structure is consistent again.
11458 The instruction may also be used if interrupt and non-interrupt code have
11459 to compete for a resource.
11460 With the atomic bit test and clear instruction interrupts
11461 \begin_inset LatexCommand \index{interrupt}
11465 don't have to be disabled for the locking operation.
11469 SDCC generates this instruction if the source follows this pattern:
11475 \begin_inset LatexCommand \index{volatile}
11479 bit resource_is_free;
11483 if (resource_is_free)
11493 resource_is_free=0;
11506 resource_is_free=1;
11513 Note, mcs51 and ds390 support only an atomic
11514 \begin_inset LatexCommand \index{atomic}
11522 instruction (as opposed to atomic bit test and
11527 Functions using private register banks
11528 \begin_inset LatexCommand \label{sub:Functions-using-private-banks}
11535 Some architectures have support for quickly changing register sets.
11536 SDCC supports this feature with the
11539 \begin_inset LatexCommand \index{using (mcs51, ds390 register bank)}
11544 \begin_inset LatexCommand \index{\_\_using (mcs51, ds390 register bank)}
11550 attribute (which tells the compiler to use a register bank
11551 \begin_inset LatexCommand \index{register bank (mcs51, ds390)}
11555 other than the default bank zero).
11556 It should only be applied to
11559 \begin_inset LatexCommand \index{interrupt}
11565 functions (see footnote below).
11566 This will in most circumstances make the generated ISR code more efficient
11567 since it will not have to save registers on the stack.
11574 attribute will have no effect on the generated code for a
11578 function (but may occasionally be useful anyway
11584 possible exception: if a function is called ONLY from 'interrupt' functions
11585 using a particular bank, it can be declared with the same 'using' attribute
11586 as the calling 'interrupt' functions.
11587 For instance, if you have several ISRs using bank one, and all of them
11588 call memcpy(), it might make sense to create a specialized version of memcpy()
11589 'using 1', since this would prevent the ISR from having to save bank zero
11590 to the stack on entry and switch to bank zero before calling the function
11597 (pending: I don't think this has been done yet)
11604 function using a non-zero bank will assume that it can trash that register
11605 bank, and will not save it.
11606 Since high-priority interrupts
11607 \begin_inset LatexCommand \index{interrupts}
11612 \begin_inset LatexCommand \index{interrupt priority}
11616 can interrupt low-priority ones on the 8051 and friends, this means that
11617 if a high-priority ISR
11621 a particular bank occurs while processing a low-priority ISR
11625 the same bank, terrible and bad things can happen.
11626 To prevent this, no single register bank should be
11630 by both a high priority and a low priority ISR.
11631 This is probably most easily done by having all high priority ISRs use
11632 one bank and all low priority ISRs use another.
11633 If you have an ISR which can change priority at runtime, you're on your
11634 own: I suggest using the default bank zero and taking the small performance
11638 It is most efficient if your ISR calls no other functions.
11639 If your ISR must call other functions, it is most efficient if those functions
11640 use the same bank as the ISR (see note 1 below); the next best is if the
11641 called functions use bank zero.
11642 It is very inefficient to call a function using a different, non-zero bank
11648 \begin_inset LatexCommand \label{sub:Startup-Code}
11653 \begin_inset LatexCommand \index{Startup code}
11660 MCS51/DS390 Startup Code
11663 The compiler inserts a call to the C routine
11665 _sdcc_external_startup()
11666 \begin_inset LatexCommand \index{\_sdcc\_external\_startup()}
11675 at the start of the CODE area.
11676 This routine is in the runtime library
11677 \begin_inset LatexCommand \index{Runtime library}
11682 By default this routine returns 0, if this routine returns a non-zero value,
11683 the static & global variable initialization will be skipped and the function
11684 main will be invoked.
11685 Otherwise static & global variables will be initialized before the function
11689 _sdcc_external_startup()
11691 routine to your program to override the default if you need to setup hardware
11692 or perform some other critical operation prior to static & global variable
11694 \begin_inset LatexCommand \index{Variable initialization}
11699 On some mcs51 variants xdata
11700 \begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
11704 memory has to be explicitly enabled before it can be accessed or if the
11705 watchdog needs to be disabled, this is the place to do it.
11706 The startup code clears all internal data memory, 256 bytes by default,
11707 but from 0 to n-1 if
11720 \begin_inset LatexCommand \index{-\/-iram-size <Value>}
11727 (recommended for Chipcon CC1010).
11730 See also the compiler option
11749 \begin_inset LatexCommand \index{-\/-no-xinit-opt}
11754 \begin_inset LatexCommand \ref{sub:MCS51-variants}
11759 about MCS51-variants.
11765 The HC08 startup code follows the same scheme as the MCS51 startup code.
11771 On the Z80 the startup code is inserted by linking with crt0.o which is generated
11772 from sdcc/device/lib/z80/crt0.s.
11773 If you need a different startup code you can use the compiler option
11794 \begin_inset LatexCommand \index{-\/-no-std-crt0}
11798 and provide your own crt0.o.
11802 Inline Assembler Code
11803 \begin_inset LatexCommand \index{Assembler routines}
11810 A Step by Step Introduction
11811 \begin_inset LatexCommand \label{sub:A-Step-by Assembler Introduction}
11818 Starting from a small snippet of c-code this example shows for the MCS51
11819 how to use inline assembly, access variables, a function parameter and
11820 an array in xdata memory.
11821 The example uses an MCS51 here but is easily adapted for other architectures.
11822 This is a buffer routine which should be optimized:
11829 \begin_inset LatexCommand \index{far (storage class)}
11834 \begin_inset LatexCommand \index{\_\_far (storage class)}
11839 \begin_inset LatexCommand \index{at}
11844 \begin_inset LatexCommand \index{\_\_at}
11849 \begin_inset LatexCommand \index{Aligned array}
11855 unsigned char head,tail;
11859 void to_buffer( unsigned char c )
11867 if( head != tail-1 )
11877 buf[ head++ ] = c;\SpecialChar ~
11881 /* access to a 256 byte aligned array */
11886 If the code snippet (assume it is saved in buffer.c) is compiled with SDCC
11887 then a corresponding buffer.asm file is generated.
11888 We define a new function
11892 in file buffer.c in which we cut and paste the generated code, removing
11893 unwanted comments and some ':'.
11895 \begin_inset Quotes sld
11899 \begin_inset Quotes srd
11903 \begin_inset Quotes sld
11907 \begin_inset Quotes srd
11910 to the beginning and the end of the function body:
11916 /* With a cut and paste from the .asm file, we have something to start with.
11921 The function is not yet OK! (registers aren't saved) */
11923 void to_buffer_asm( unsigned char c )
11932 \begin_inset LatexCommand \index{\_asm}
11937 \begin_inset LatexCommand \index{\_\_asm}
11951 ;buffer.c if( head != tail-1 )
11999 ;buffer.c buf[ head++ ] = c; /* access to a 256 byte aligned array */
12000 \begin_inset LatexCommand \index{Aligned array}
12065 \begin_inset LatexCommand \index{\_endasm}
12070 \begin_inset LatexCommand \index{\_\_endasm}
12079 The new file buffer.c should compile with only one warning about the unreferenced
12080 function argument 'c'.
12081 Now we hand-optimize the assembly code and insert an #define USE_ASSEMBLY
12082 (1) and finally have:
12088 unsigned char far at 0x7f00 buf[0x100];
12090 unsigned char head,tail;
12092 #define USE_ASSEMBLY (1)
12100 void to_buffer( unsigned char c )
12108 if( head != tail-1 )
12128 void to_buffer( unsigned char c )
12136 c; // to avoid warning: unreferenced function argument
12143 \begin_inset LatexCommand \index{\_asm}
12148 \begin_inset LatexCommand \index{\_\_asm}
12162 ; save used registers here.
12173 ; If we were still using r2,r3 we would have to push them here.
12176 ; if( head != tail-1 )
12219 ; we could do an ANL a,#0x0f here to use a smaller buffer (see below)
12243 ; buf[ head++ ] = c;
12254 a,dpl \SpecialChar ~
12261 ; dpl holds lower byte of function argument
12272 dpl,_head \SpecialChar ~
12275 ; buf is 0x100 byte aligned so head can be used directly
12317 ; we could do an ANL _head,#0x0f here to use a smaller buffer (see above)
12329 ; restore used registers here
12336 \begin_inset LatexCommand \index{\_endasm}
12341 \begin_inset LatexCommand \index{\_\_endasm}
12352 The inline assembler code can contain any valid code understood by the assembler
12353 , this includes any assembler directives and comment lines
12359 The assembler does not like some characters like ':' or ''' in comments.
12360 You'll find an 100+ pages assembler manual in sdcc/as/doc/asxhtm.html
12361 \begin_inset LatexCommand \index{asXXXX (as-gbz80, as-hc08, asx8051, as-z80)}
12366 \begin_inset LatexCommand \index{Assembler documentation}
12374 The compiler does not do any validation of the code within the
12377 \begin_inset LatexCommand \index{\_asm}
12382 \begin_inset LatexCommand \index{\_\_asm}
12390 \begin_inset LatexCommand \index{\_endasm}
12395 \begin_inset LatexCommand \index{\_\_endasm}
12404 Specifically it will not know which registers are used and thus register
12406 \begin_inset LatexCommand \index{push/pop}
12410 has to be done manually.
12414 It is recommended that each assembly instruction (including labels) be placed
12415 in a separate line (as the example shows).
12429 \begin_inset LatexCommand \index{-\/-peep-asm}
12435 command line option is used, the inline assembler code will be passed through
12436 the peephole optimizer
12437 \begin_inset LatexCommand \index{Peephole optimizer}
12442 There are only a few (if any) cases where this option makes sense, it might
12443 cause some unexpected changes in the inline assembler code.
12444 Please go through the peephole optimizer rules defined in file
12448 before using this option.
12452 \begin_inset LatexCommand \label{sub:Naked-Functions}
12457 \begin_inset LatexCommand \index{Naked functions}
12464 A special keyword may be associated with a function declaring it as
12467 \begin_inset LatexCommand \index{\_naked}
12472 \begin_inset LatexCommand \index{\_\_naked}
12483 function modifier attribute prevents the compiler from generating prologue
12484 \begin_inset LatexCommand \index{function prologue}
12489 \begin_inset LatexCommand \index{function epilogue}
12493 code for that function.
12494 This means that the user is entirely responsible for such things as saving
12495 any registers that may need to be preserved, selecting the proper register
12496 bank, generating the
12500 instruction at the end, etc.
12501 Practically, this means that the contents of the function must be written
12502 in inline assembler.
12503 This is particularly useful for interrupt functions, which can have a large
12504 (and often unnecessary) prologue/epilogue.
12505 For example, compare the code generated by these two functions:
12511 \begin_inset LatexCommand \index{volatile}
12515 data unsigned char counter;
12519 void simpleInterrupt(void) interrupt
12520 \begin_inset LatexCommand \index{interrupt}
12525 \begin_inset LatexCommand \index{\_\_interrupt}
12543 void nakedInterrupt(void) interrupt 2 _naked
12552 \begin_inset LatexCommand \index{\_asm}
12557 \begin_inset LatexCommand \index{\_\_asm}
12574 _counter ; does not change flags, no need to save psw
12586 ; MUST explicitly include ret or reti in _naked function.
12593 \begin_inset LatexCommand \index{\_endasm}
12598 \begin_inset LatexCommand \index{\_\_endasm}
12607 For an 8051 target, the generated simpleInterrupt looks like:
12748 whereas nakedInterrupt looks like:
12763 _counter ; does not change flags, no need to save psw
12781 ; MUST explicitly include ret or reti in _naked function
12784 The related directive #pragma exclude
12785 \begin_inset LatexCommand \index{\#pragma exclude}
12789 allows a more fine grained control over pushing & popping
12790 \begin_inset LatexCommand \index{push/pop}
12797 While there is nothing preventing you from writing C code inside a
12801 function, there are many ways to shoot yourself in the foot doing this,
12802 and it is recommended that you stick to inline assembler.
12805 Use of Labels within Inline Assembler
12808 SDCC allows the use of in-line assembler with a few restrictions regarding
12810 In older versions of the compiler all labels defined within inline assembler
12819 where nnnn is a number less than 100 (which implies a limit of utmost 100
12820 inline assembler labels
12834 \begin_inset LatexCommand \index{\_asm}
12839 \begin_inset LatexCommand \index{\_\_asm}
12869 \begin_inset LatexCommand \index{\_endasm}
12874 \begin_inset LatexCommand \index{\_\_endasm}
12881 Inline assembler code cannot reference any C-Labels, however it can reference
12883 \begin_inset LatexCommand \index{Labels}
12887 defined by the inline assembler, e.g.:
12912 ; some assembler code
12932 /* some more c code */
12934 clabel:\SpecialChar ~
12936 /* inline assembler cannot reference this label */
12948 $0003: ;label (can be referenced by inline assembler only)
12955 \begin_inset LatexCommand \index{\_endasm}
12960 \begin_inset LatexCommand \index{\_\_endasm}
12970 /* some more c code */
12975 In other words inline assembly code can access labels defined in inline
12976 assembly within the scope of the function.
12977 The same goes the other way, i.e.
12978 labels defines in inline assembly can not be accessed by C statements.
12981 Interfacing with Assembler Code
12982 \begin_inset LatexCommand \index{Assembler routines}
12989 Global Registers used for Parameter Passing
12990 \begin_inset LatexCommand \index{Parameter passing}
12997 The compiler always uses the global registers
13000 \begin_inset LatexCommand \index{DPTR, DPH, DPL}
13005 \begin_inset LatexCommand \index{DPTR}
13010 \begin_inset LatexCommand \index{B (mcs51, ds390 register)}
13019 \begin_inset LatexCommand \index{ACC (mcs51, ds390 register)}
13025 to pass the first parameter to a routine.
13026 The second parameter onwards is either allocated on the stack (for reentrant
13037 -stack-auto is used) or in data / xdata memory (depending on the memory
13042 Assembler Routine (non-reentrant)
13045 In the following example
13046 \begin_inset LatexCommand \index{reentrant}
13051 \begin_inset LatexCommand \index{Assembler routines (non-reentrant)}
13055 the function c_func calls an assembler routine asm_func, which takes two
13057 \begin_inset LatexCommand \index{function parameter}
13066 extern int asm_func(unsigned char, unsigned char);
13070 int c_func (unsigned char i, unsigned char j)
13078 return asm_func(i,j);
13092 return c_func(10,9);
13097 The corresponding assembler function is:
13102 .globl _asm_func_PARM_2
13203 \begin_inset LatexCommand \index{DPTR, DPH, DPL}
13220 Note here that the return values
13221 \begin_inset LatexCommand \index{return value}
13225 are placed in 'dpl' - One byte return value, 'dpl' LSB & 'dph' MSB for
13227 'dpl', 'dph' and 'b' for three byte values (generic pointers) and 'dpl','dph','
13228 b' & 'acc' for four byte values.
13231 The parameter naming convention is _<function_name>_PARM_<n>, where n is
13232 the parameter number starting from 1, and counting from the left.
13233 The first parameter is passed in
13234 \begin_inset Quotes eld
13238 \begin_inset Quotes erd
13241 for a one byte parameter,
13242 \begin_inset Quotes eld
13246 \begin_inset Quotes erd
13250 \begin_inset Quotes eld
13254 \begin_inset Quotes erd
13257 for three bytes and
13258 \begin_inset Quotes eld
13262 \begin_inset Quotes erd
13265 for a four bytes parameter.
13266 The variable name for the second parameter will be _<function_name>_PARM_2.
13270 Assemble the assembler routine with the following command:
13277 asx8051 -losg asmfunc.asm
13284 Then compile and link the assembler routine to the C source file with the
13292 sdcc cfunc.c asmfunc.rel
13295 Assembler Routine (reentrant)
13299 \begin_inset LatexCommand \index{reentrant}
13304 \begin_inset LatexCommand \index{Assembler routines (reentrant)}
13308 the second parameter
13309 \begin_inset LatexCommand \index{function parameter}
13313 onwards will be passed on the stack, the parameters are pushed from right
13315 after the call the leftmost parameter will be on the top of the stack.
13316 Here is an example:
13321 extern int asm_func(unsigned char, unsigned char);
13325 int c_func (unsigned char i, unsigned char j) reentrant
13333 return asm_func(i,j);
13347 return c_func(10,9);
13352 The corresponding assembler routine is:
13452 The compiling and linking procedure remains the same, however note the extra
13453 entry & exit linkage required for the assembler code, _bp is the stack
13454 frame pointer and is used to compute the offset into the stack for parameters
13455 and local variables.
13459 \begin_inset LatexCommand \index{int (16 bit)}
13464 \begin_inset LatexCommand \index{long (32 bit)}
13471 For signed & unsigned int (16 bit) and long (32 bit) variables, division,
13472 multiplication and modulus operations are implemented by support routines.
13473 These support routines are all developed in ANSI-C to facilitate porting
13474 to other MCUs, although some model specific assembler optimizations are
13476 The following files contain the described routines, all of them can be
13477 found in <installdir>/share/sdcc/lib.
13483 \begin_inset Tabular
13484 <lyxtabular version="3" rows="11" columns="2">
13486 <column alignment="center" valignment="top" leftline="true" width="0">
13487 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
13488 <row topline="true" bottomline="true">
13489 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
13499 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
13510 <row topline="true">
13511 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
13519 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
13524 16 bit multiplication
13528 <row topline="true">
13529 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
13537 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
13542 signed 16 bit division (calls _divuint)
13546 <row topline="true">
13547 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
13555 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
13560 unsigned 16 bit division
13564 <row topline="true">
13565 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
13573 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
13578 signed 16 bit modulus (calls _moduint)
13582 <row topline="true">
13583 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
13591 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
13596 unsigned 16 bit modulus
13600 <row topline="true">
13601 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
13609 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
13614 32 bit multiplication
13618 <row topline="true">
13619 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
13627 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
13632 signed 32 division (calls _divulong)
13636 <row topline="true">
13637 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
13645 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
13650 unsigned 32 division
13654 <row topline="true">
13655 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
13663 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
13668 signed 32 bit modulus (calls _modulong)
13672 <row topline="true" bottomline="true">
13673 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
13681 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
13686 unsigned 32 bit modulus
13699 Since they are compiled as
13704 \begin_inset LatexCommand \index{reentrant}
13709 \begin_inset LatexCommand \index{interrupt}
13713 service routines should not do any of the above operations.
13714 If this is unavoidable then the above routines will need to be compiled
13728 \begin_inset LatexCommand \index{-\/-stack-auto}
13734 option, after which the source program will have to be compiled with
13747 \begin_inset LatexCommand \index{-\/-int-long-reent}
13754 Notice that you don't have to call these routines directly.
13755 The compiler will use them automatically every time an integer operation
13759 Floating Point Support
13760 \begin_inset LatexCommand \index{Floating point support}
13767 SDCC supports IEEE (single precision 4 bytes) floating point numbers.The
13768 floating point support routines are derived from gcc's floatlib.c and consist
13769 of the following routines:
13777 \begin_inset Tabular
13778 <lyxtabular version="3" rows="17" columns="2">
13780 <column alignment="center" valignment="top" leftline="true" width="0">
13781 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
13782 <row topline="true" bottomline="true">
13783 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
13800 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
13809 <row topline="true">
13810 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
13827 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
13841 add floating point numbers
13845 <row topline="true">
13846 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
13863 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
13877 subtract floating point numbers
13881 <row topline="true">
13882 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
13899 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
13913 divide floating point numbers
13917 <row topline="true">
13918 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
13935 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
13949 multiply floating point numbers
13953 <row topline="true">
13954 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
13971 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
13985 convert floating point to unsigned char
13989 <row topline="true">
13990 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
14007 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
14021 convert floating point to signed char
14025 <row topline="true">
14026 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
14043 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
14057 convert floating point to unsigned int
14061 <row topline="true">
14062 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
14079 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
14093 convert floating point to signed int
14097 <row topline="true">
14098 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
14124 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
14138 convert floating point to unsigned long
14142 <row topline="true">
14143 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
14160 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
14174 convert floating point to signed long
14178 <row topline="true">
14179 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
14196 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
14210 convert unsigned char to floating point
14214 <row topline="true">
14215 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
14232 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
14246 convert char to floating point number
14250 <row topline="true">
14251 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
14268 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
14282 convert unsigned int to floating point
14286 <row topline="true">
14287 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
14304 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
14318 convert int to floating point numbers
14322 <row topline="true">
14323 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
14340 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
14354 convert unsigned long to floating point number
14358 <row topline="true" bottomline="true">
14359 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
14376 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
14390 convert long to floating point number
14403 These support routines are developed in ANSI-C so there is room for space
14404 and speed improvement
14410 The floating point routines for the mcs51 are implemented in assembler
14414 Note if all these routines are used simultaneously the data space might
14416 For serious floating point usage the large model might be needed.
14417 Also notice that you don't have to call this routines directly.
14418 The compiler will use them automatically every time a floating point operation
14423 \begin_inset LatexCommand \index{Libraries}
14432 <pending: this is messy and incomplete - a little more information is in
14433 sdcc/doc/libdoc.txt
14438 Compiler support routines (_gptrget, _mulint etc.)
14441 Stdclib functions (puts, printf, strcat etc.)
14442 \layout Subsubsection
14448 \begin_inset LatexCommand \index{<stdio.h>}
14452 As usual on embedded systems you have to provide your own
14455 \begin_inset LatexCommand \index{getchar()}
14464 \begin_inset LatexCommand \index{putchar()}
14471 SDCC does not know whether the system connects to a serial line with or
14472 without handshake, LCD, keyboard or other device.
14473 You'll find examples for serial routines f.e.
14474 in sdcc/device/lib.
14480 \begin_inset LatexCommand \index{printf()}
14490 does not support float (except on ds390).
14491 To enable this recompile it with the option
14504 \begin_inset LatexCommand \index{USE\_FLOATS}
14510 on the command line.
14524 \begin_inset LatexCommand \index{-\/-model-large}
14530 for the mcs51 port, since this uses a lot of memory.
14533 If you're short on memory you might want to use
14536 \begin_inset LatexCommand \index{printf\_small()}
14551 For the mcs51 there additionally are assembly versions
14554 \begin_inset LatexCommand \index{printf\_tiny() (mcs51)}
14563 \begin_inset LatexCommand \index{printf\_fast() (mcs51)}
14572 \begin_inset LatexCommand \index{printf\_fast\_f() (mcs51)}
14578 which should fit the requirements of many embedded systems (printf_fast()
14579 can be customized by unsetting #defines to
14583 support long variables and field widths).
14586 Math functions (sin, pow, sqrt etc.)
14593 \begin_inset LatexCommand \index{Libraries}
14597 included in SDCC should have a license at least as liberal as the GNU Lesser
14598 General Public License
14599 \begin_inset LatexCommand \index{GNU Lesser General Public License, LGPL}
14610 license statements for the libraries are missing.
14611 sdcc/device/lib/ser_ir.c
14615 come with a GPL (as opposed to LGPL) License - this will not be liberal
14616 enough for many embedded programmers.
14619 If you have ported some library or want to share experience about some code
14621 falls into any of these categories Busses (I
14622 \begin_inset Formula $^{\textrm{2}}$
14625 C, CAN, Ethernet, Profibus, Modbus, USB, SPI, JTAG ...), Media (IDE, Memory
14626 cards, eeprom, flash...), En-/Decryption, Remote debugging, Realtime kernel,
14627 Keyboard, LCD, RTC, FPGA, PID then the sdcc-user mailing list
14628 \begin_inset LatexCommand \url{http://sourceforge.net/mail/?group_id=599}
14633 would certainly like to hear about it.
14634 Programmers coding for embedded systems are not especially famous for being
14635 enthusiastic, so don't expect a big hurray but as the mailing list is searchabl
14636 e these references are very valuable.
14637 Let's help to create a climate where information is shared.
14643 MCS51 Memory Models
14644 \begin_inset LatexCommand \index{Memory model}
14649 \begin_inset LatexCommand \index{MCS51 memory model}
14654 \layout Subsubsection
14659 SDCC allows two memory models for MCS51 code,
14668 Modules compiled with different memory models should
14672 be combined together or the results would be unpredictable.
14673 The library routines supplied with the compiler are compiled as both small
14675 The compiled library modules are contained in separate directories as small
14676 and large so that you can link to either set.
14680 When the large model is used all variables declared without a storage class
14681 will be allocated into the external ram, this includes all parameters and
14682 local variables (for non-reentrant
14683 \begin_inset LatexCommand \index{reentrant}
14688 When the small model is used variables without storage class are allocated
14689 in the internal ram.
14692 Judicious usage of the processor specific storage classes
14693 \begin_inset LatexCommand \index{Storage class}
14697 and the 'reentrant' function type will yield much more efficient code,
14698 than using the large model.
14699 Several optimizations are disabled when the program is compiled using the
14700 large model, it is therefore recommended that the small model be used unless
14701 absolutely required.
14702 \layout Subsubsection
14705 \begin_inset LatexCommand \label{sub:External-Stack}
14710 \begin_inset LatexCommand \index{stack}
14715 \begin_inset LatexCommand \index{External stack (mcs51)}
14722 The external stack (-
14733 \begin_inset LatexCommand \index{-\/-xstack}
14737 ) is located in pdata
14738 \begin_inset LatexCommand \index{pdata (mcs51, ds390 storage class)}
14742 memory (usually at the start of the external ram segment) and uses all
14743 unused space in pdata (max.
14755 -xstack option is used to compile the program, the parameters and local
14757 \begin_inset LatexCommand \index{local variables}
14761 of all reentrant functions are allocated in this area.
14762 This option is provided for programs with large stack space requirements.
14763 When used with the -
14774 \begin_inset LatexCommand \index{-\/-stack-auto}
14778 option, all parameters and local variables are allocated on the external
14779 stack (note: support libraries will need to be recompiled with the same
14781 There is a predefined target in the library makefile).
14784 The compiler outputs the higher order address byte of the external ram segment
14786 \begin_inset LatexCommand \index{P2 (mcs51 sfr)}
14791 \begin_inset LatexCommand \ref{sub:MCS51-variants}
14795 ), therefore when using the External Stack option, this port
14799 be used by the application program.
14803 \begin_inset LatexCommand \index{Memory model}
14808 \begin_inset LatexCommand \index{DS390 memory model}
14815 The only model supported is Flat 24
14816 \begin_inset LatexCommand \index{Flat 24 (DS390 memory model)}
14821 This generates code for the 24 bit contiguous addressing mode of the Dallas
14823 In this mode, up to four meg of external RAM or code space can be directly
14825 See the data sheets at www.dalsemi.com for further information on this part.
14829 Note that the compiler does not generate any code to place the processor
14830 into 24 bitmode (although
14834 in the ds390 libraries will do that for you).
14840 \begin_inset LatexCommand \index{Tinibios (DS390)}
14844 , the boot loader or similar code must ensure that the processor is in 24
14845 bit contiguous addressing mode before calling the SDCC startup code.
14863 option, variables will by default be placed into the XDATA segment.
14868 Segments may be placed anywhere in the 4 meg address space using the usual
14880 Note that if any segments are located above 64K, the -r flag must be passed
14881 to the linker to generate the proper segment relocations, and the Intel
14882 HEX output format must be used.
14883 The -r flag can be passed to the linker by using the option
14887 on the SDCC command line.
14888 However, currently the linker can not handle code segments > 64k.
14892 \begin_inset LatexCommand \index{Pragmas}
14899 SDCC supports the following #pragma directives:
14903 \begin_inset LatexCommand \index{\#pragma save}
14907 - this will save all current options to the save/restore stack.
14908 See #pragma\SpecialChar ~
14913 \begin_inset LatexCommand \index{\#pragma restore}
14917 - will restore saved options from the last save.
14918 saves & restores can be nested.
14919 SDCC uses a save/restore stack: save pushes current options to the stack,
14920 restore pulls current options from the stack.
14921 See #pragma\SpecialChar ~
14928 \begin_inset LatexCommand \index{\#pragma callee\_saves}
14933 \begin_inset LatexCommand \index{function prologue}
14937 function1[,function2[,function3...]] - The compiler by default uses a caller
14938 saves convention for register saving across function calls, however this
14939 can cause unnecessary register pushing & popping
14940 \begin_inset LatexCommand \index{push/pop}
14944 when calling small functions from larger functions.
14945 This option can be used to switch off the register saving convention for
14946 the function names specified.
14947 The compiler will not save registers when calling these functions, extra
14948 code need to be manually inserted at the entry & exit for these functions
14949 to save & restore the registers used by these functions, this can SUBSTANTIALLY
14950 reduce code & improve run time performance of the generated code.
14951 In the future the compiler (with inter procedural analysis) may be able
14952 to determine the appropriate scheme to use for each function call.
14963 -callee-saves command line option is used, the function names specified
14964 in #pragma\SpecialChar ~
14966 \begin_inset LatexCommand \index{\#pragma callee\_saves}
14970 is appended to the list of functions specified in the command line.
14974 \begin_inset LatexCommand \index{\#pragma exclude}
14978 none | {acc[,b[,dpl[,dph]]] - The exclude pragma disables the generation
14979 of pairs of push/pop
14980 \begin_inset LatexCommand \index{push/pop}
14989 \begin_inset LatexCommand \index{interrupt}
15002 The directive should be placed immediately before the ISR function definition
15003 and it affects ALL ISR functions following it.
15004 To enable the normal register saving for ISR functions use #pragma\SpecialChar ~
15005 exclude\SpecialChar ~
15007 \begin_inset LatexCommand \index{\#pragma exclude}
15012 See also the related keyword _naked
15013 \begin_inset LatexCommand \index{\_naked}
15018 \begin_inset LatexCommand \index{\_\_naked}
15026 \begin_inset LatexCommand \index{\#pragma less\_pedantic}
15030 - the compiler will not warn you anymore for obvious mistakes, you'r on
15034 disable_warning <nnnn>
15035 \begin_inset LatexCommand \index{\#pragma disable\_warning}
15039 - the compiler will not warn you anymore about warning number <nnnn>.
15043 \begin_inset LatexCommand \index{\#pragma nogcse}
15047 - will stop global common subexpression elimination.
15051 \begin_inset LatexCommand \index{\#pragma noinduction}
15055 - will stop loop induction optimizations.
15059 \begin_inset LatexCommand \index{\#pragma noinvariant}
15063 - will not do loop invariant optimizations.
15064 For more details see Loop Invariants in section
15065 \begin_inset LatexCommand \ref{sub:Loop-Optimizations}
15073 \begin_inset LatexCommand \index{\#pragma noiv}
15077 - Do not generate interrupt
15078 \begin_inset LatexCommand \index{interrupt}
15082 vector table entries for all ISR functions defined after the pragma.
15083 This is useful in cases where the interrupt vector table must be defined
15084 manually, or when there is a secondary, manually defined interrupt vector
15086 for the autovector feature of the Cypress EZ-USB FX2).
15087 More elegantly this can be achieved by obmitting the optional interrupt
15088 number after the interrupt keyword, see section
15089 \begin_inset LatexCommand \ref{sub:Interrupt-Service-Routines}
15098 \begin_inset LatexCommand \index{\#pragma nojtbound}
15102 - will not generate code for boundary value checking, when switch statements
15103 are turned into jump-tables (dangerous).
15104 For more details see section
15105 \begin_inset LatexCommand \ref{sub:'switch'-Statements}
15113 \begin_inset LatexCommand \index{\#pragma noloopreverse}
15117 - Will not do loop reversal optimization
15121 \begin_inset LatexCommand \index{\#pragma nooverlay}
15125 - the compiler will not overlay the parameters and local variables of a
15130 \begin_inset LatexCommand \index{\#pragma stackauto}
15145 \begin_inset LatexCommand \index{-\/-stack-auto}
15150 \begin_inset LatexCommand \ref{sec:Parameters-and-Local-Variables}
15154 Parameters and Local Variables.
15158 \begin_inset LatexCommand \index{\#pragma opt\_code\_speed}
15162 - The compiler will optimize code generation towards fast code, possibly
15163 at the expense of code size.
15167 \begin_inset LatexCommand \index{\#pragma opt\_code\_size}
15171 - The compiler will optimize code generation towards compact code, possibly
15172 at the expense of code speed.
15176 \begin_inset LatexCommand \index{\#pragma opt\_code\_balanced}
15180 - The compiler will attempt to generate code that is both compact and fast,
15181 as long as meeting one goal is not a detriment to the other (this is the
15187 \begin_inset LatexCommand \index{\#pragma std\_sdcc89}
15191 - Generally follow the C89 standard, but allow SDCC features that conflict
15192 with the standard (default).
15196 \begin_inset LatexCommand \index{\#pragma std\_c89}
15200 - Follow the C89 standard and disable SDCC features that conflict with the
15205 \begin_inset LatexCommand \index{\#pragma std\_sdcc99}
15209 - Generally follow the C99 standard, but allow SDCC features that conflict
15210 with the standard (incomplete support).
15214 \begin_inset LatexCommand \index{\#pragma std\_c99}
15218 - Follow the C99 standard and disable SDCC features that conflict with the
15219 standard (incomplete support).
15222 SDCPP supports the following #pragma directives:
15226 \begin_inset LatexCommand \index{\#pragma preproc\_asm}
15230 (+ | -) - switch _asm _endasm block preprocessing on / off.
15234 The pragma's are intended to be used to turn-on or off certain optimizations
15235 which might cause the compiler to generate extra stack / data space to
15236 store compiler generated temporary variables.
15237 This usually happens in large functions.
15238 Pragma directives should be used as shown in the following example, they
15239 are used to control options & optimizations for a given function; pragmas
15240 should be placed before and/or after a function, placing pragma's inside
15241 a function body could have unpredictable results.
15247 \begin_inset LatexCommand \index{\#pragma save}
15258 /* save the current settings */
15261 \begin_inset LatexCommand \index{\#pragma nogcse}
15270 /* turnoff global subexpression elimination */
15272 #pragma noinduction
15273 \begin_inset LatexCommand \index{\#pragma noinduction}
15277 /* turn off induction optimizations */
15300 \begin_inset LatexCommand \index{\#pragma restore}
15304 /* turn the optimizations back on */
15307 The compiler will generate a warning message when extra space is allocated.
15308 It is strongly recommended that the save and restore pragma's be used when
15309 changing options for a function.
15312 Defines Created by the Compiler
15315 The compiler creates the following #defines
15316 \begin_inset LatexCommand \index{\#defines}
15321 \begin_inset LatexCommand \index{Defines created by the compiler}
15331 \begin_inset Tabular
15332 <lyxtabular version="3" rows="10" columns="2">
15334 <column alignment="center" valignment="top" leftline="true" width="0">
15335 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
15336 <row topline="true" bottomline="true">
15337 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15347 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15358 <row topline="true">
15359 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15365 \begin_inset LatexCommand \index{SDCC}
15372 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15377 this Symbol is always defined
15381 <row topline="true">
15382 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15388 \begin_inset LatexCommand \index{SDCC\_mcs51}
15393 \begin_inset LatexCommand \index{SDCC\_ds390}
15398 \begin_inset LatexCommand \index{SDCC\_z80}
15405 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15410 depending on the model used (e.g.: -mds390
15414 <row topline="true">
15415 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15421 \begin_inset LatexCommand \index{\_\_mcs51}
15426 \begin_inset LatexCommand \index{\_\_ds390}
15431 \begin_inset LatexCommand \index{\_\_hc08}
15436 \begin_inset LatexCommand \index{\_\_z80}
15443 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15448 depending on the model used (e.g.
15453 <row topline="true">
15454 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15460 \begin_inset LatexCommand \index{SDCC\_STACK\_AUTO}
15467 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15490 <row topline="true">
15491 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15497 \begin_inset LatexCommand \index{SDCC\_MODEL\_SMALL}
15504 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15527 <row topline="true">
15528 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15534 \begin_inset LatexCommand \index{SDCC\_MODEL\_LARGE}
15541 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15564 <row topline="true">
15565 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15571 \begin_inset LatexCommand \index{SDCC\_USE\_XSTACK}
15578 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15601 <row topline="true">
15602 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15608 \begin_inset LatexCommand \index{SDCC\_STACK\_TENBIT}
15615 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15628 <row topline="true" bottomline="true">
15629 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15635 \begin_inset LatexCommand \index{SDCC\_MODEL\_FLAT24}
15642 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15662 Notes on supported Processors
15666 \begin_inset LatexCommand \label{sub:MCS51-variants}
15671 \begin_inset LatexCommand \index{MCS51 variants}
15678 MCS51 processors are available from many vendors and come in many different
15680 While they might differ considerably in respect to Special Function Registers
15681 the core MCS51 is usually not modified or is kept compatible.
15685 pdata access by SFR
15688 With the upcome of devices with internal xdata and flash memory devices
15690 \begin_inset LatexCommand \index{P2 (mcs51 sfr)}
15694 as dedicated I/O port is becoming more popular.
15695 Switching the high byte for pdata
15696 \begin_inset LatexCommand \index{pdata (mcs51, ds390 storage class)}
15700 access which was formerly done by port P2 is then achieved by a Special
15702 \begin_inset LatexCommand \index{sfr}
15707 In well-established MCS51 tradition the address of this
15711 is where the chip designers decided to put it.
15712 Needless to say that they didn't agree on a common name either.
15713 So that the startup code can correctly initialize xdata variables, you
15714 should define an sfr with the name _XPAGE
15717 \begin_inset LatexCommand \index{\_XPAGE (mcs51)}
15723 at the appropriate location if the default, port P2, is not used for this.
15729 sfr at 0x92 _XPAGE; /* Cypress EZ-USB family */
15734 sfr at 0xaf _XPAGE; /* some Silicon Labs (Cygnal) chips */
15739 sfr at 0xaa _XPAGE; /* some Silicon Labs (Cygnal) chips */
15742 For more exotic implementations further customizations may be needed.
15744 \begin_inset LatexCommand \ref{sub:Startup-Code}
15748 for other possibilities.
15751 Other Features available by SFR
15754 Some MCS51 variants offer features like Double DPTR
15755 \begin_inset LatexCommand \index{DPTR}
15759 , multiple DPTR, decrementing DPTR, 16x16 Multiply.
15760 These are currently not used for the MCS51 port.
15761 If you absolutely need them you can fall back to inline assembly or submit
15768 The DS80C400 microcontroller has a rich set of peripherals.
15769 In its built-in ROM library it includes functions to access some of the
15770 features, among them is a TCP stack with IP4 and IP6 support.
15771 Library headers (currently in beta status) and other files are provided
15775 \begin_inset LatexCommand \url{ftp://ftp.dalsemi.com/pub/tini/ds80c400/c_libraries/sdcc/index.html}
15783 The Z80 and gbz80 port
15786 SDCC can target both the Zilog
15787 \begin_inset LatexCommand \index{Z80}
15791 and the Nintendo Gameboy's Z80-like gbz80
15792 \begin_inset LatexCommand \index{gbz80 (GameBoy Z80)}
15797 The Z80 port is passed through the same
15800 \begin_inset LatexCommand \index{Regression test}
15806 as the MCS51 and DS390 ports, so floating point support, support for long
15807 variables and bitfield support is fine.
15808 See mailing lists and forums about interrupt routines.
15811 As always, the code is the authoritative reference - see z80/ralloc.c and
15814 \begin_inset LatexCommand \index{stack}
15818 frame is similar to that generated by the IAR Z80 compiler.
15819 IX is used as the base pointer, HL and IY are used as a temporary registers,
15820 and BC and DE are available for holding variables.
15822 \begin_inset LatexCommand \index{return value}
15826 for the Z80 port are stored in L (one byte), HL (two bytes), or DEHL (four
15828 The gbz80 port use the same set of registers for the return values, but
15829 in a different order of significance: E (one byte), DE (two bytes), or
15836 The port to the Motorola HC08
15837 \begin_inset LatexCommand \index{HC08}
15841 family has been added in October 2003, and is still undergoing some basic
15843 The code generator is complete, but the register allocation is still quite
15845 Some of the SDCC's standard C library functions have embedded non-HC08
15846 inline assembly and so are not yet usable.
15857 \begin_inset LatexCommand \index{PIC14}
15861 port still requires a major effort from the development community.
15862 However it can work for very simple code.
15865 C code and 14bit PIC code page
15866 \begin_inset LatexCommand \index{code page (pic14)}
15871 \begin_inset LatexCommand \index{RAM bank (pic14)}
15878 The linker organizes allocation for the code page and RAM banks.
15879 It does not have intimate knowledge of the code flow.
15880 It will put all the code section of a single asm file into a single code
15882 In order to make use of multiple code pages, separate asm files must be
15884 The compiler treats all functions of a single C file as being in the same
15885 code page unless it is non static.
15886 The compiler treats all local variables of a single C file as being in
15887 the same RAM bank unless it is an extern.
15891 To get the best follow these guide lines:
15894 make local functions static, as non static functions require code page selection
15898 Make local variables static as extern variables require RAM bank selection
15902 For devices that have multiple code pages it is more efficient to use the
15903 same number of files as pages, i.e.
15904 for the 16F877 use 4 separate files and i.e.
15905 for the 16F874 use 2 separate files.
15906 This way the linker can put the code for each file into different code
15907 pages and the compiler can allocate reusable variables more efficiently
15908 and there's less page selection overhead.
15909 And as for any 8 bit micro (especially for PIC 14 as they have a very simple
15910 instruction set) use 'unsigned char' whereever possible instead of 'int'.
15913 Creating a device include file
15916 For generating a device include file use the support perl script inc2h.pl
15917 kept in directory support/script.
15923 For the interrupt function, use the keyword 'interrupt'
15924 \begin_inset LatexCommand \index{interrupt}
15928 with level number of 0 (PIC14 only has 1 interrupt so this number is only
15929 there to avoid a syntax error - it ought to be fixed).
15935 void Intr(void) interrupt 0
15941 T0IF = 0; /* Clear timer interrupt */
15946 Linking and assembling
15949 For assembling you can use either GPUTILS'
15950 \begin_inset LatexCommand \index{gputils (pic tools)}
15954 gpasm.exe or MPLAB's mpasmwin.exe.
15955 GPUTILS is available from
15956 \begin_inset LatexCommand \url{http://sourceforge.net/projects/gputils}
15961 For linking you can use either GPUTIL's gplink or MPLAB's mplink.exe.
15962 If you use MPLAB and an interrupt function then the linker script file
15963 vectors section will need to be enlarged to link with mplink.
15986 sdcc -S -V -mpic14 -p16F877 $<
16000 $(PRJ).hex: $(OBJS)
16010 gplink -m -s $(PRJ).lkr -o $(PRJ).hex $(OBJS)
16032 sdcc -S -V -mpic14 -p16F877 $<
16042 mpasmwin /q /o $*.asm
16046 $(PRJ).hex: $(OBJS)
16056 mplink /v $(PRJ).lkr /m $(PRJ).map /o $(PRJ).hex $(OBJS)
16059 Please note that indentations within a
16063 have to be done with a tabulator character.
16067 \begin_inset LatexCommand \index{PIC16}
16075 \begin_inset LatexCommand \index{PIC16}
16079 port is the portion of SDCC that is responsible to produce code for the
16081 \begin_inset LatexCommand \index{Microchip}
16085 (TM) microcontrollers with 16 bit core.
16086 Currently this family of microcontrollers contains the PIC18Fxxx and PIC18Fxxxx.
16087 Currently supported devices are:
16091 \begin_inset Tabular
16092 <lyxtabular version="3" rows="4" columns="6">
16094 <column alignment="center" valignment="top" leftline="true" width="0">
16095 <column alignment="center" valignment="top" leftline="true" width="0">
16096 <column alignment="center" valignment="top" leftline="true" width="0">
16097 <column alignment="center" valignment="top" leftline="true" width="0">
16098 <column alignment="center" valignment="top" leftline="true" width="0">
16099 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
16100 <row topline="true">
16101 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
16109 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
16117 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
16125 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
16133 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
16141 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
16150 <row topline="true">
16151 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
16159 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
16167 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
16175 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
16183 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
16191 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
16200 <row topline="true">
16201 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
16209 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
16217 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
16225 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
16233 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
16241 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
16250 <row topline="true" bottomline="true">
16251 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
16259 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
16267 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
16275 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
16282 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
16289 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
16307 PIC16 port supports the standard command line arguments as supposed, with
16308 the exception of certain cases that will be mentioned in the following
16311 \labelwidthstring 00.00.0000
16323 -callee-saves See -
16335 \labelwidthstring 00.00.0000
16347 -all-callee-saves All function arguments are passed on stack by default.
16350 There is no need to specify this in the command line.
16352 \labelwidthstring 00.00.0000
16364 -fommit-frame-pointer Frame pointer will be omitted when the function uses
16365 no local variables.
16368 Port Specific Options
16369 \begin_inset LatexCommand \index{Options PIC16}
16376 The port specific options appear after the global options in the sdcc --help
16378 \layout Subsubsection
16383 General options enable certain port features and optimizations.
16385 \labelwidthstring 00.00.0000
16397 -stack-model=[model] Used in conjuction with the command above.
16398 Defines the stack model to be used, valid stack models are :
16401 \labelwidthstring 00.00.0000
16407 Selects small stack model.
16408 8 bit stack and frame pointers.
16409 Supports 256 bytes stack size.
16411 \labelwidthstring 00.00.0000
16417 Selects large stack model.
16418 16 bit stack and frame pointers.
16419 Supports 65536 bytes stack size.
16422 \labelwidthstring 00.00.0000
16434 -preplace-udata-with=[kword] Replaces the default udata keyword for allocating
16435 unitialized data variables with [kword].
16436 Valid keywords are: "udata_acs", "udata_shr", "udata_ovr".
16438 \labelwidthstring 00.00.0000
16450 -ivt-loc <nnnn> positions the Interrupt Vector Table at location <nnnn>.
16451 Useful for bootloaders.
16453 \labelwidthstring 00.00.0000
16465 -asm= sets the full path and name of an external assembler to call.
16467 \labelwidthstring 00.00.0000
16479 -link= sets the full path and name of an external linker to call.
16481 \labelwidthstring 00.00.0000
16493 -mplab-comp MPLAB compatibility option.
16494 Currently only suppresses special gpasm directives.
16495 \layout Subsubsection
16497 Optimization Options
16499 \labelwidthstring 00.00.0000
16511 -optimize-goto Try to use (conditional) BRA instead of GOTO
16513 \labelwidthstring 00.00.0000
16525 -optimize-cmp Try to optimize some compares.
16527 \labelwidthstring 00.00.0000
16539 -obanksel=nn Set optimization level for inserting BANKSELs.
16544 \labelwidthstring 00.00.0000
16548 \labelwidthstring 00.00.0000
16550 1 checks previous used register and if it is the same then does not emit
16551 BANKSEL, accounts only for labels.
16553 \labelwidthstring 00.00.0000
16555 2 tries to check the location of (even different) symbols and removes BANKSELs
16556 if they are in the same bank.
16561 Important: There might be problems if the linker script has data sections
16562 across bank borders!
16564 \layout Subsubsection
16568 \labelwidthstring 00.00.0000
16580 -nodefaultlibs do not link default libraries when linking
16582 \labelwidthstring 00.00.0000
16594 -no-crt Don't link the default run-time modules
16596 \labelwidthstring 00.00.0000
16608 -use-crt= Use a custom run-time module instead of the defaults.
16609 \layout Subsubsection
16614 Debugging options enable extra debugging information in the output files.
16616 \labelwidthstring 00.00.0000
16628 -debug-xtra Similar to -
16639 \begin_inset LatexCommand \index{-\/-debug}
16643 , but dumps more information.
16645 \labelwidthstring 00.00.0000
16657 -debug-ralloc Force register allocator to dump <source>.d file with debugging
16659 <source> is the name of the file compiled.
16661 \labelwidthstring 00.00.0000
16673 -pcode-verbose Enable pcode debugging information in translation.
16675 \labelwidthstring 00.00.0000
16687 -denable-peeps Force the usage of peepholes.
16690 \labelwidthstring 00.00.0000
16702 -gstack Trace push/pops for stack pointer overflow
16704 \labelwidthstring 00.00.0000
16716 -call-tree dump call tree in .calltree file
16719 Enviromental Variables
16722 There is a number of enviromental variables that can be used when running
16723 SDCC to enable certain optimizations or force a specific program behaviour.
16724 these variables are primarily for debugging purposes so they can be enabled/dis
16728 Currently there is only two such variables available:
16730 \labelwidthstring 00.00.0000
16732 OPTIMIZE_BITFIELD_POINTER_GET when this variable exists reading of structure
16733 bitfields is optimized by directly loading FSR0 with the address of the
16734 bitfield structure.
16735 Normally SDCC will cast the bitfield structure to a bitfield pointer and
16737 This step saves data ram and code space for functions that perform heavy
16740 80 bytes of code space are saved when compiling malloc.c with this option).
16743 \labelwidthstring 00.00.0000
16745 NO_REG_OPT do not perform pCode registers optimization.
16746 This should be used for debugging purposes.
16747 In some where bugs in the pcode optimizer are found, users can benefit
16748 from temporarily disabling the optimizer until the bug is fixed.
16751 Preprocessor Macros
16754 PIC16 port defines the following preprocessor macros while translating a
16759 \begin_inset Tabular
16760 <lyxtabular version="3" rows="6" columns="2">
16762 <column alignment="center" valignment="top" leftline="true" width="0">
16763 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
16764 <row topline="true" bottomline="true">
16765 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
16773 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
16782 <row topline="true">
16783 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
16791 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
16796 Port identification
16800 <row topline="true">
16801 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
16819 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
16824 Port identification (same as above)
16828 <row topline="true">
16829 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
16837 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
16842 MCU Identification.
16847 is the microcontrol identification number, i.e.
16852 <row topline="true">
16853 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
16871 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
16876 MCU Identification (same as above)
16880 <row topline="true" bottomline="true">
16881 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
16889 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
16894 nnn = SMALL or LARGE respectively according to the stack model used
16905 In addition the following macros are defined when calling assembler:
16909 \begin_inset Tabular
16910 <lyxtabular version="3" rows="4" columns="2">
16912 <column alignment="center" valignment="top" leftline="true" width="0">
16913 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
16914 <row topline="true" bottomline="true">
16915 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
16923 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
16932 <row topline="true">
16933 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
16941 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
16946 MCU Identification.
16951 is the microcontrol identification number, i.e.
16956 <row topline="true">
16957 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
16965 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
16970 nnn = SMALL or LARGE respectively according to the memory model used for
16975 <row topline="true" bottomline="true">
16976 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
16984 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
16989 nnn = SMALL or LARGE respectively according to the stack model used
17004 \begin_inset LatexCommand \index{PIC16}
17008 port uses the following directories for searching header files and libraries.
17012 \begin_inset Tabular
17013 <lyxtabular version="3" rows="3" columns="4">
17015 <column alignment="center" valignment="top" leftline="true" width="0">
17016 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
17017 <column alignment="center" valignment="top" width="0">
17018 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
17019 <row topline="true" bottomline="true">
17020 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17028 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17036 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17044 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17053 <row topline="true">
17054 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17059 PREFIX/sdcc/include/pic16
17062 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17067 PIC16 specific headers
17070 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17078 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17087 <row topline="true" bottomline="true">
17088 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17093 PREFIX/sdcc/lib/pic16
17096 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17101 PIC16 specific libraries
17104 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17112 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17129 \begin_inset LatexCommand \label{sub:PIC16_Pragmas}
17136 PIC16 port currently supports the following pragmas:
17138 \labelwidthstring 00.00.0000
17140 stack pragma stack forces the code generator to initialize the stack & frame
17141 pointers at a specific address.
17142 This is an adhoc solution for cases where no STACK directive is available
17143 in the linker script or gplink is not instructed to create a stack section.
17145 The stack pragma should be used only once in a project.
17146 Multiple pragmas may result in indeterminate behaviour of the program.
17152 The old format (ie.
17153 #pragma stack 0x5ff) is deprecated and will cause the stack pointer to
17154 cross page boundaries (or even exceed the available data RAM) and crash
17156 Make sure that stack does not cross page boundaries when using the SMALL
17162 The format is as follows:
17165 #pragma stack bottom_address [stack_size]
17172 is the lower bound of the stack section.
17173 The stack pointer initially will point at address (bottom_address+stack_size-1).
17181 /* initializes stack of 100 bytes at RAM address 0x200 */
17184 #pragma stack 0x200 100
17187 If the stack_size field is omitted then a stack is created with the default
17189 This size might be enough for most programs, but its not enough for operations
17190 with deep function nesting or excessive stack usage.
17192 \labelwidthstring 00.00.0000
17196 This pragma is deprecated.
17197 Its use will cause a warning message to be issued.
17203 \labelwidthstring 00.00.0000
17205 code place a function symbol at static FLASH address
17213 /* place function test_func at 0x4000 */
17216 #pragma code test_func 0x4000
17220 \labelwidthstring 00.00.0000
17222 library instructs the linker to use a library module.
17227 #pragma library module_name
17234 can be any library or object file (including its path).
17235 Note that there are four reserved keywords which have special meaning.
17240 \begin_inset Tabular
17241 <lyxtabular version="3" rows="6" columns="3">
17243 <column alignment="center" valignment="top" leftline="true" width="0">
17244 <column alignment="block" valignment="top" leftline="true" width="20page%">
17245 <column alignment="left" valignment="top" leftline="true" rightline="true" width="0">
17246 <row topline="true" bottomline="true">
17247 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17255 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17263 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17272 <row topline="true">
17273 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17283 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17288 ignore all library pragmas
17291 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17302 <row topline="true">
17303 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17313 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17321 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17334 <row topline="true">
17335 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17345 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17350 link the Math libarary
17353 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17366 <row topline="true">
17367 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17377 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17382 link the I/O library
17385 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17398 <row topline="true" bottomline="true">
17399 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17409 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17414 link the debug library
17417 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17436 * is the device number, i.e.
17437 452 for PIC18F452 MCU.
17440 This feature allows for linking with specific libraries withoug having to
17441 explicit name them in the command line.
17446 keyword will reject all modules specified by the library pragma.
17448 \labelwidthstring 00.00.0000
17450 udata pragma udata instructs the compiler to emit code so that linker will
17451 place a variable at a specific memory bank
17459 /* places variable foo at bank2 */
17462 #pragma udata bank2 foo
17468 In order for this pragma to work extra SECTION directives should be added
17469 in the .lkr script.
17470 In the following example a sample .lkr file is shown:
17475 // Sample linker script for the PIC18F452 processor
17481 CODEPAGE NAME=vectors START=0x0 END=0x29 PROTECTED
17484 CODEPAGE NAME=page START=0x2A END=0x7FFF
17487 CODEPAGE NAME=idlocs START=0x200000 END=0x200007 PROTECTED
17490 CODEPAGE NAME=config START=0x300000 END=0x30000D PROTECTED
17493 CODEPAGE NAME=devid START=0x3FFFFE END=0x3FFFFF PROTECTED
17496 CODEPAGE NAME=eedata START=0xF00000 END=0xF000FF PROTECTED
17499 ACCESSBANK NAME=accessram START=0x0 END=0x7F
17504 DATABANK NAME=gpr0 START=0x80 END=0xFF
17507 DATABANK NAME=gpr1 START=0x100 END=0x1FF
17510 DATABANK NAME=gpr2 START=0x200 END=0x2FF
17513 DATABANK NAME=gpr3 START=0x300 END=0x3FF
17516 DATABANK NAME=gpr4 START=0x400 END=0x4FF
17519 DATABANK NAME=gpr5 START=0x500 END=0x5FF
17522 ACCESSBANK NAME=accesssfr START=0xF80 END=0xFFF PROTECTED
17527 SECTION NAME=CONFIG ROM=config
17532 SECTION NAME=bank0 RAM=gpr0 # these SECTION directives
17535 SECTION NAME=bank1 RAM=gpr1 # should be added to link
17538 SECTION NAME=bank2 RAM=gpr2 # section name 'bank?' with
17541 SECTION NAME=bank3 RAM=gpr3 # a specific DATABANK name
17544 SECTION NAME=bank4 RAM=gpr4
17547 SECTION NAME=bank5 RAM=gpr5
17550 The linker will recognise the section name set in the pragma statement and
17551 will position the variable at the memory bank set with the RAM field at
17552 the SECTION line in the linker script file.
17556 \begin_inset LatexCommand \label{sub:PIC16_Header-Files}
17563 There is one main header file that can be included to the source files using
17570 This header file contains the definitions for the processor special registers,
17571 so it is necessary if the source accesses them.
17572 It can be included by adding the following line in the beginning of the
17576 #include <pic18fregs.h>
17579 The specific microcontroller is selected within the pic18fregs.h automatically,
17580 so the same source can be used with a variety of devices.
17586 The libraries that PIC16
17587 \begin_inset LatexCommand \index{PIC16}
17591 port depends on are the microcontroller device libraries which contain
17592 the symbol definitions for the microcontroller special function registers.
17593 These libraries have the format pic18fxxxx.lib, where
17597 is the microcontroller identification number.
17598 The specific library is selected automatically by the compiler at link
17599 stage according to the selected device.
17602 Libraries are created with gplib which is part of the gputils package
17603 \begin_inset LatexCommand \url{http://sourceforge.net/projects/gputils}
17608 \layout Subsubsection*
17610 Building the libraries
17613 Before using SDCC/pic16 there are some libraries that need to be compiled.
17614 This process is not done automatically by SDCC since not all users use
17615 SDCC for pic16 projects.
17616 So each user should compile the libraries separately.
17619 The steps to compile the pic16 libraries under Linux are:
17622 cd device/lib/pic16
17637 su -c 'make install' # install the libraries, you need the root password
17640 If you need to install the headers too, do:
17646 su -c 'make install' # install the headers, you need the root password
17649 There exist a special target to build the I/O libraries.
17650 This target is not automatically build because it will build the I/O library
17656 This way building will take quite a lot of time.
17657 Users are advised to edit the
17659 device/lib/pic16/pics.build
17661 file and then execute:
17670 The following memory models are supported by the PIC16 port:
17679 Memory model affects the default size of pointers within the source.
17680 The sizes are shown in the next table:
17684 \begin_inset Tabular
17685 <lyxtabular version="3" rows="3" columns="3">
17687 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
17688 <column alignment="center" valignment="top" leftline="true" width="0">
17689 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
17690 <row topline="true" bottomline="true">
17691 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17696 Pointer sizes according to memory model
17699 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17707 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17716 <row topline="true" bottomline="true">
17717 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17725 <cell multicolumn="1" alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17733 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17742 <row topline="true" bottomline="true">
17743 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17751 <cell multicolumn="1" alignment="center" valignment="top" topline="true" bottomline="true" leftline="true" usebox="none">
17759 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17775 It is advisable that all sources within a project are compiled with the
17777 If one wants to override the default memory model, this can be done by
17778 declaring a pointer as
17787 Far selects large memory model's pointers, while near selects small memory
17791 The standard device libraries (see
17792 \begin_inset LatexCommand \ref{sub:PIC16_Header-Files}
17796 ) contain no reference to pointers, so they can be used with both memory
17803 The stack implementation for the PIC16 port uses two indirect registers,
17806 \labelwidthstring 00.00.0000
17808 FSR1 is assigned as stack pointer
17810 \labelwidthstring 00.00.0000
17812 FSR2 is assigned as frame pointer
17815 The following stack models are supported by the PIC16 port
17836 model means that only the FSRxL byte is used to access stack and frame,
17843 uses both FSRxL and FSRxH registers.
17844 The following table shows the stack/frame pointers sizes according to stack
17845 model and the maximum space they can address:
17849 \begin_inset Tabular
17850 <lyxtabular version="3" rows="3" columns="3">
17852 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
17853 <column alignment="center" valignment="top" leftline="true" width="0">
17854 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
17855 <row topline="true" bottomline="true">
17856 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17861 Stack & Frame pointer sizes according to stack model
17864 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17872 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17881 <row topline="true">
17882 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17890 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17898 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17907 <row topline="true" bottomline="true">
17908 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17916 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17924 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17944 stack model is currently not working properly throughout the code generator.
17945 So its use is not advised.
17946 Also there are some other points that need special care:
17951 Do not create stack sections with size more than one physical bank (that
17955 Stack sections should no cross physical bank limits (i.e.
17956 #pragma stack 0x50 0x100)
17959 These limitations are caused by the fact that only FSRxL is modified when
17960 using SMALL stack model, so no more than 256 bytes of stack can be used.
17961 This problem will disappear after LARGE model is fully implemented.
17967 In addition to the standard SDCC function keywords, PIC16 port makes available
17970 \labelwidthstring 00.00.0000
17972 wparam Use the WREG to pass one byte of the first function argument.
17973 This improves speed but you may not use this for functions with arguments
17974 that are called via function pointers, otherwise the first byte of the
17975 first parameter will get lost.
17979 void func_wparam(int a) wparam
17985 /* WREG hold the lower part of a */
17988 /* the high part of a is stored in FSR2+2 (or +3 for large stack model)
17998 This keyword replaces the deprecated wparam pragma.
18000 \labelwidthstring 00.00.0000
18002 shadowregs When entering/exiting an ISR, it is possible to take advantage
18003 of the PIC18F hardware shadow registers which hold the values of WREG,
18004 STATUS and BSR registers.
18005 This can be done by adding the keyword
18013 keyword in the function's header.
18016 void isr_shadow(void) shadowregs interrupt 1
18032 instructs the code generator not to store/restore WREG, STATUS, BSR when
18033 entering/exiting the ISR.
18036 Function return values
18039 Return values from functions are placed to the appropriate registers following
18040 a modified Microchip policy optimized for SDCC.
18041 The following table shows these registers:
18045 \begin_inset Tabular
18046 <lyxtabular version="3" rows="6" columns="2">
18048 <column alignment="center" valignment="top" leftline="true" width="0">
18049 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
18050 <row topline="true" bottomline="true">
18051 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18059 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18064 destination register
18068 <row topline="true">
18069 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18077 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18086 <row topline="true">
18087 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18095 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18104 <row topline="true">
18105 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18113 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18122 <row topline="true">
18123 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18131 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18136 FSR0L:PRODH:PRODL:WREG
18140 <row topline="true" bottomline="true">
18141 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18149 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18154 on stack, FSR0 points to the beginning
18168 An interrupt servive routine (ISR) is declared using the
18175 void isr(void) interrupt
18193 is the interrupt number, which for PIC18F devices can be:
18197 \begin_inset Tabular
18198 <lyxtabular version="3" rows="4" columns="3">
18200 <column alignment="center" valignment="top" leftline="true" width="0">
18201 <column alignment="center" valignment="top" leftline="true" width="0">
18202 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
18203 <row topline="true" bottomline="true">
18204 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18214 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18222 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18227 Interrupt Vector Address
18231 <row topline="true">
18232 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18240 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18248 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18257 <row topline="true">
18258 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18275 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18289 HIGH priority interrupts
18292 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18301 <row topline="true" bottomline="true">
18302 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18310 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18315 LOW priority interrupts
18318 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18334 When generating assembly code for ISR the code generator places a
18340 Interrupt Vector Address
18342 which points at the genetated ISR.
18343 This single GOTO instruction is part of an automatically generated
18345 interrupt entry point
18348 The actuall ISR code is placed as normally would in the code space.
18349 Upon interrupt request, the GOTO instruction is executed which jumps to
18351 When declaring interrupt functions as _naked this GOTO instruction is
18356 The whole interrupt functions is therefore placed at the Interrupt Vector
18357 Address of the specific interrupt.
18358 This is not a problem for the LOW priority interrupts, but it is a problem
18359 for the RESET and the HIGH priority interrupts because code may be written
18360 at the next interrupt´s vector address and cause undeterminate program
18361 behaviour if that interrupt is raised.
18367 This is not a problem when
18370 this is a HIGH interrupt ISR and LOW interrupts are
18377 when the ISR is small enough not to reach the next interrupt´s vector address.
18387 is possible to be omitted.
18388 This way a function is generated similar to an ISR, but it is not assigned
18392 When entering an interrupt, currently the PIC16
18393 \begin_inset LatexCommand \index{PIC16}
18397 port automatically saves the following registers:
18409 PROD (PRODL and PRODH)
18412 FSR0 (FSR0L and FSR0H)
18415 These registers are restored upon return from the interrupt routine.
18421 NOTE that when the _naked attribute is specified for an interrupt routine,
18422 then NO registers are stored or restored.
18431 Generic pointers are implemented in PIC16 port as 3-byte (24-bit) types.
18432 There are 3 types of generic pointers currently implemented data, code
18433 and eeprom pointers.
18434 They are differentiated by the value of the 7th and 6th bits of the upper
18439 \begin_inset Tabular
18440 <lyxtabular version="3" rows="5" columns="5">
18442 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
18443 <column alignment="center" valignment="top" width="0">
18444 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
18445 <column alignment="center" valignment="top" width="0">
18446 <column alignment="left" valignment="top" rightline="true" width="0">
18447 <row topline="true" bottomline="true">
18448 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18456 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18464 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18472 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18477 rest of the pointer
18480 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18489 <row topline="true" bottomline="true">
18490 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18498 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18506 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18514 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18523 uuuuuu uuuuxxxx xxxxxxxx
18526 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18531 a 12-bit data pointer in data RAM memory
18535 <row bottomline="true">
18536 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18544 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18552 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18560 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18569 uxxxxx xxxxxxxx xxxxxxxx
18572 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18577 a 21-bit code pointer in FLASH memory
18581 <row bottomline="true">
18582 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18590 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18598 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18606 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18615 uuuuuu uuuuuuxx xxxxxxxx
18618 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18623 a 10-bit eeprom pointer in EEPROM memory
18627 <row bottomline="true">
18628 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18636 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18644 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18652 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18661 xxxxxx xxxxxxxx xxxxxxxx
18664 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18669 unimplemented pointer type
18680 Generic pointer are read and written with a set of library functions which
18681 read/write 1, 2, 3, 4 bytes.
18685 \layout Subsubsection
18687 Standard I/O Streams
18694 the type FILE is defined as:
18697 typedef char * FILE;
18700 This type is the stream type implemented I/O in the PIC18F devices.
18701 Also the standard input and output streams are declared in stdio.h:
18704 extern FILE * stdin;
18707 extern FILE * stdout;
18710 The FILE type is actually a generic pointer which defines one more type
18711 of generic pointers, the
18716 This new type has the format:
18720 \begin_inset Tabular
18721 <lyxtabular version="3" rows="2" columns="7">
18723 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
18724 <column alignment="center" valignment="top" width="0">
18725 <column alignment="center" valignment="top" leftline="true" width="0">
18726 <column alignment="center" valignment="top" leftline="true" width="0">
18727 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
18728 <column alignment="center" valignment="top" width="0">
18729 <column alignment="left" valignment="top" rightline="true" width="0">
18730 <row topline="true" bottomline="true">
18731 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18739 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18747 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18755 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18763 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18771 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18776 rest of the pointer
18779 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18788 <row topline="true" bottomline="true">
18789 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18797 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18805 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18813 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18821 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18829 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18841 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18846 upper byte high nubble is 0x2n, the rest are zeroes
18857 Currently implemented there are 3 types of streams defined:
18861 \begin_inset Tabular
18862 <lyxtabular version="3" rows="4" columns="4">
18864 <column alignment="center" valignment="top" leftline="true" width="0">
18865 <column alignment="center" valignment="top" leftline="true" width="0">
18866 <column alignment="center" valignment="top" leftline="true" width="0">
18867 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
18868 <row topline="true" bottomline="true">
18869 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18877 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18885 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18893 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18902 <row topline="true">
18903 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18911 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18921 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18929 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18934 Writes/Reads characters via the USART peripheral
18938 <row topline="true">
18939 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18947 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18957 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18965 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18970 Writes/Reads characters via the MSSP peripheral
18974 <row topline="true" bottomline="true">
18975 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18983 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18993 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19001 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19006 Writes/Reads characters via used defined functions
19017 The stream identifiers are declared as macros in the stdio.h header.
19020 In the libc library there exist the functions that are used to write to
19021 each of the above streams.
19024 \labelwidthstring 00.00.0000
19036 _stream_usart_putchar writes a character at the USART stream
19038 \labelwidthstring 00.00.0000
19050 _stream_mssp_putchar writes a character at the MSSP stream
19052 \labelwidthstring 00.00.0000
19054 putchar dummy function.
19055 This writes a character to a user specified manner.
19058 In order to increase performance
19062 is declared in stdio.h as having its parameter in WREG (it has the wparam
19064 In stdio.h exists the macro PUTCHAR(arg) that defines the putchar function
19065 in a user-friendly way.
19070 is the name of the variable that holds the character to print.
19071 An example follows:
19074 #include <pic18fregs.h>
19086 PORTA = c; /* dump character c to PORTA */
19099 stdout = STREAM_USER; /* this is not necessery, since stdout points
19102 * by default to STREAM_USER */
19105 printf (¨This is a printf test
19113 \layout Subsubsection
19118 PIC16 contains an implementation of the printf-family of functions.
19119 There exist the following functions:
19122 extern unsigned int sprintf(char *buf, char *fmt, ...);
19125 extern unsigned int vsprintf(char *buf, char *fmt, va_list ap);
19130 extern unsigned int printf(char *fmt, ...);
19133 extern unsigned int vprintf(char *fmt, va_lista ap);
19138 extern unsigned int fprintf(FILE *fp, char *fmt, ...);
19141 extern unsigned int vfprintf(FILE *fp, char *fmt, va_list ap);
19144 For sprintf and vsprintf
19148 should normally be a data pointer where the resulting string will be placed.
19149 No range checking is done so the user should allocate the necessery buffer.
19150 For fprintf and vfprintf
19154 should be a stream pointer (i.e.
19155 stdout, STREAM_MSSP, etc...).
19156 \layout Subsubsection
19161 The PIC18F family of microcontrollers supports a number of interrupt sources.
19162 A list of these interrupts is shown in the following table:
19166 \begin_inset Tabular
19167 <lyxtabular version="3" rows="11" columns="4">
19169 <column alignment="left" valignment="top" leftline="true" width="0">
19170 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
19171 <column alignment="left" valignment="top" leftline="true" width="0">
19172 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
19173 <row topline="true" bottomline="true">
19174 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19182 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19190 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19198 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19207 <row topline="true">
19208 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19216 <cell multicolumn="1" alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19221 PORTB change interrupt
19224 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19232 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19237 EEPROM/FLASH write complete interrupt
19241 <row topline="true">
19242 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19250 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19255 INT0 external interrupt
19258 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19266 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19271 Bus collision interrupt
19275 <row topline="true">
19276 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19284 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19289 INT1 external interrupt
19292 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19300 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19305 Low voltage detect interrupt
19309 <row topline="true">
19310 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19318 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19323 INT2 external interrupt
19326 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19334 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19339 Parallel slave port interrupt
19343 <row topline="true">
19344 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19352 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19357 CCP1 module interrupt
19360 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19368 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19373 AD convertion complete interrupt
19377 <row topline="true">
19378 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19386 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19391 CCP2 module interrupt
19394 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19402 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19407 USART receive interrupt
19411 <row topline="true">
19412 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19420 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19425 TMR0 overflow interrupt
19428 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19436 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19441 USART transmit interrupt
19445 <row topline="true">
19446 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19454 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19459 TMR1 overflow interrupt
19462 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19470 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19475 SSP receive/transmit interrupt
19479 <row topline="true">
19480 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19488 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19493 TMR2 matches PR2 interrupt
19496 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19503 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19511 <row topline="true" bottomline="true">
19512 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19520 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19525 TMR3 overflow interrupt
19528 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19535 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19550 The prototypes for these names are defined in the header file
19557 In order to simplify signal handling, a number of macros is provided:
19559 \labelwidthstring 00.00.0000
19561 DEF_INTHIGH(name) begin the definition of the interrupt dispatch table for
19562 high priority interrupts.
19567 is the function name to use.
19569 \labelwidthstring 00.00.0000
19571 DEF_INTLOW(name) begin the definition of the interrupt dispatch table fo
19572 low priority interrupt.
19577 is the function name to use.
19579 \labelwidthstring 00.00.0000
19581 DEF_HANDLER(sig,handler) define a handler for signal
19585 \labelwidthstring 00.00.0000
19587 END_DEF end the declaration of the dispatch table.
19590 Additionally there are two more macros to simplify the declaration of the
19593 \labelwidthstring 00.00.0000
19597 SIGHANDLER(handler)
19599 this declares the function prototype for the
19605 \labelwidthstring 00.00.0000
19607 SIGHANDLERNAKED(handler) same as SIGHANDLER() but declares a naked function.
19610 An example of using the macros above is shown below:
19613 #include <pic18fregs.h>
19616 #include <signal.h>
19620 DEF_INTHIGH(high_int)
19623 DEF_HANDLER(SIG_TMR0, _tmr0_handler)
19626 DEF_HANDLER(SIG_BCOL, _bcol_handler)
19633 SIGHANDLER(_tmr0_handler)
19639 /* action to be taken when timer 0 overflows */
19646 SIGHANDLERNAKED(_bcol_handler)
19655 /* action to be taken when bus collision occurs */
19671 Special care should be taken when using the above scheme:
19674 do not place a colon (;) at the end of the DEF_* and END_DEF macros.
19677 when declaring SIGHANDLERNAKED handler never forget to use
19681 for proper returning.
19687 Here you can find some general tips for compiling programs with SDCC/pic16.
19688 \layout Subsubsection
19693 The default stack size (that is 64 bytes) probably is enough for many programs.
19694 One must take care that when there are many levels of function nesting,
19695 or there is excessive usage of stack, its size should be extended.
19696 An example of such a case is the printf/sprintf family of functions.
19697 If you encounter problems like not being able to print integers, then you
19698 need to set the stack size around the maximum (256 for small stack model).
19699 The following diagram shows what happens when calling printf to print an
19703 printf () --> ltoa () --> ultoa () --> divschar ()
19706 It is should be understood that stack is easily consumed when calling complicate
19708 Using command line arguments like -
19718 -fommit-frame-pointer might reduce stack usage by not creating unnecessery
19720 Other ways to reduce stack usage may exist.
19723 Debugging with SDCDB
19724 \begin_inset LatexCommand \label{cha:Debugging-with-SDCDB}
19729 \begin_inset LatexCommand \index{sdcdb (debugger)}
19736 SDCC is distributed with a source level debugger
19737 \begin_inset LatexCommand \index{Debugger}
19742 The debugger uses a command line interface, the command repertoire of the
19743 debugger has been kept as close to gdb
19744 \begin_inset LatexCommand \index{gdb}
19748 (the GNU debugger) as possible.
19749 The configuration and build process is part of the standard compiler installati
19750 on, which also builds and installs the debugger in the target directory
19751 specified during configuration.
19752 The debugger allows you debug BOTH at the C source and at the ASM source
19754 Sdcdb is available on Unix platforms only.
19757 Compiling for Debugging
19771 \begin_inset LatexCommand \index{-\/-debug}
19775 option must be specified for all files for which debug information is to
19777 The complier generates a .adb file for each of these files.
19778 The linker creates the .cdb
19779 \begin_inset LatexCommand \index{<file>.cdb}
19784 \begin_inset LatexCommand \index{<file>.adb}
19788 files and the address information.
19789 This .cdb is used by the debugger.
19792 How the Debugger Works
19805 -debug option is specified the compiler generates extra symbol information
19806 some of which are put into the assembler source and some are put into the
19808 Then the linker creates the .cdb file from the individual .adb files with
19809 the address information for the symbols.
19810 The debugger reads the symbolic information generated by the compiler &
19811 the address information generated by the linker.
19812 It uses the SIMULATOR (Daniel's S51) to execute the program, the program
19813 execution is controlled by the debugger.
19814 When a command is issued for the debugger, it translates it into appropriate
19815 commands for the simulator.
19818 Starting the Debugger
19821 The debugger can be started using the following command line.
19822 (Assume the file you are debugging has the file name foo).
19836 The debugger will look for the following files.
19839 foo.c - the source file.
19842 foo.cdb - the debugger symbol information file.
19845 foo.ihx - the Intel hex format
19846 \begin_inset LatexCommand \index{Intel hex format}
19853 Command Line Options
19866 -directory=<source file directory> this option can used to specify the directory
19868 The debugger will look into the directory list specified for source, cdb
19870 The items in the directory list must be separated by ':', e.g.
19871 if the source files can be in the directories /home/src1 and /home/src2,
19882 -directory option should be -
19892 -directory=/home/src1:/home/src2.
19893 Note there can be no spaces in the option.
19897 -cd <directory> - change to the <directory>.
19900 -fullname - used by GUI front ends.
19903 -cpu <cpu-type> - this argument is passed to the simulator please see the
19904 simulator docs for details.
19907 -X <Clock frequency > this options is passed to the simulator please see
19908 the simulator docs for details.
19911 -s <serial port file> passed to simulator see the simulator docs for details.
19914 -S <serial in,out> passed to simulator see the simulator docs for details.
19917 -k <port number> passed to simulator see the simulator docs for details.
19923 As mentioned earlier the command interface for the debugger has been deliberatel
19924 y kept as close the GNU debugger gdb, as possible.
19925 This will help the integration with existing graphical user interfaces
19926 (like ddd, xxgdb or xemacs) existing for the GNU debugger.
19927 If you use a graphical user interface for the debugger you can skip this
19929 \layout Subsubsection*
19931 break [line | file:line | function | file:function]
19934 Set breakpoint at specified line or function:
19943 sdcdb>break foo.c:100
19945 sdcdb>break funcfoo
19947 sdcdb>break foo.c:funcfoo
19948 \layout Subsubsection*
19950 clear [line | file:line | function | file:function ]
19953 Clear breakpoint at specified line or function:
19962 sdcdb>clear foo.c:100
19964 sdcdb>clear funcfoo
19966 sdcdb>clear foo.c:funcfoo
19967 \layout Subsubsection*
19972 Continue program being debugged, after breakpoint.
19973 \layout Subsubsection*
19978 Execute till the end of the current function.
19979 \layout Subsubsection*
19984 Delete breakpoint number 'n'.
19985 If used without any option clear ALL user defined break points.
19986 \layout Subsubsection*
19988 info [break | stack | frame | registers ]
19991 info break - list all breakpoints
19994 info stack - show the function call stack.
19997 info frame - show information about the current execution frame.
20000 info registers - show content of all registers.
20001 \layout Subsubsection*
20006 Step program until it reaches a different source line.
20007 Note: pressing <return> repeats the last command.
20008 \layout Subsubsection*
20013 Step program, proceeding through subroutine calls.
20014 \layout Subsubsection*
20019 Start debugged program.
20020 \layout Subsubsection*
20025 Print type information of the variable.
20026 \layout Subsubsection*
20031 print value of variable.
20032 \layout Subsubsection*
20037 load the given file name.
20038 Note this is an alternate method of loading file for debugging.
20039 \layout Subsubsection*
20044 print information about current frame.
20045 \layout Subsubsection*
20050 Toggle between C source & assembly source.
20051 \layout Subsubsection*
20053 ! simulator command
20056 Send the string following '!' to the simulator, the simulator response is
20058 Note the debugger does not interpret the command being sent to the simulator,
20059 so if a command like 'go' is sent the debugger can loose its execution
20060 context and may display incorrect values.
20061 \layout Subsubsection*
20068 My name is Bobby Brown"
20071 Interfacing with DDD
20074 The screenshot was converted from png to eps with:
20075 \begin_inset Quotes sld
20078 bmeps -c -e8f -p3 ddd_example.png >ddd_example.eps
20079 \begin_inset Quotes srd
20082 which produces a pretty compact eps file which is free from compression
20086 The screenshot was included in sdccman.lyx cvs version 1.120 but later removed
20087 as this broke the build system on Sourceforge (pdf-file was broken).
20093 \begin_inset LatexCommand \url{http://cvs.sourceforge.net/viewcvs.py/*checkout*/sdcc/sdcc/doc/figures/ddd_example.eps}
20099 shows a screenshot of a debugging session with DDD
20100 \begin_inset LatexCommand \index{DDD (debugger)}
20104 (Unix only) on a simulated 8032.
20105 The debugging session might not run as smoothly as the screenshot suggests.
20106 The debugger allows setting of breakpoints, displaying and changing variables,
20107 single stepping through C and assembler code.
20110 The source was compiled with
20133 -debug ddd_example.c
20146 and DDD was invoked with
20153 ddd -debugger 'sdcdb -cpu 8032 ddd_example'
20156 Interfacing with XEmacs
20157 \begin_inset LatexCommand \index{XEmacs}
20162 \begin_inset LatexCommand \index{Emacs}
20169 Two files (in emacs lisp) are provided for the interfacing with XEmacs,
20170 sdcdb.el and sdcdbsrc.el.
20171 These two files can be found in the $(prefix)/bin directory after the installat
20173 These files need to be loaded into XEmacs for the interface to work.
20174 This can be done at XEmacs startup time by inserting the following into
20175 your '.xemacs' file (which can be found in your HOME directory):
20181 (load-file sdcdbsrc.el)
20187 .xemacs is a lisp file so the () around the command is REQUIRED.
20188 The files can also be loaded dynamically while XEmacs is running, set the
20189 environment variable 'EMACSLOADPATH' to the installation bin directory
20190 (<installdir>/bin), then enter the following command ESC-x load-file sdcdbsrc.
20191 To start the interface enter the following command:
20205 You will prompted to enter the file name to be debugged.
20210 The command line options that are passed to the simulator directly are bound
20211 to default values in the file sdcdbsrc.el.
20212 The variables are listed below, these values maybe changed as required.
20215 sdcdbsrc-cpu-type '51
20218 sdcdbsrc-frequency '11059200
20221 sdcdbsrc-serial nil
20224 The following is a list of key mapping for the debugger interface.
20235 ;;key\SpecialChar ~
20249 binding\SpecialChar ~
20273 ;;---\SpecialChar ~
20287 -------\SpecialChar ~
20329 sdcdb-next-from-src\SpecialChar ~
20357 sdcdb-back-from-src\SpecialChar ~
20385 sdcdb-cont-from-src\SpecialChar ~
20395 SDCDB continue command
20413 sdcdb-step-from-src\SpecialChar ~
20441 sdcdb-whatis-c-sexp\SpecialChar ~
20451 SDCDB ptypecommand for data at
20518 sdcdbsrc-delete\SpecialChar ~
20532 SDCDB Delete all breakpoints if no arg
20581 given or delete arg (C-u arg x)
20599 sdcdbsrc-frame\SpecialChar ~
20614 SDCDB Display current frame if no arg,
20663 given or display frame arg
20730 sdcdbsrc-goto-sdcdb\SpecialChar ~
20740 Goto the SDCDB output buffer
20758 sdcdb-print-c-sexp\SpecialChar ~
20769 SDCDB print command for data at
20836 sdcdbsrc-goto-sdcdb\SpecialChar ~
20846 Goto the SDCDB output buffer
20864 sdcdbsrc-mode\SpecialChar ~
20880 Toggles Sdcdbsrc mode (turns it off)
20895 sdcdb-finish-from-src\SpecialChar ~
20903 SDCDB finish command
20918 sdcdb-break\SpecialChar ~
20936 Set break for line with point
20951 sdcdbsrc-mode\SpecialChar ~
20967 Toggle Sdcdbsrc mode
20982 sdcdbsrc-srcmode\SpecialChar ~
21005 Here are a few guidelines that will help the compiler generate more efficient
21006 code, some of the tips are specific to this compiler others are generally
21007 good programming practice.
21010 Use the smallest data type to represent your data-value.
21011 If it is known in advance that the value is going to be less than 256 then
21012 use an 'unsigned char' instead of a 'short' or 'int'.
21013 Please note, that ANSI C requires both signed and unsigned chars to be
21014 promoted to 'signed int' before doing any operation.
21016 \begin_inset LatexCommand \index{type promotion}
21020 can be omitted, if the result is the same.
21021 The effect of the promotion rules together with the sign-extension is often
21028 unsigned char uc = 0xfe;
21030 if (uc * uc < 0) /* this is true! */
21049 (int) uc * (int) uc = (int) 0xfe * (int) 0xfe = (int) 0xfc04 = -1024
21059 (unsigned char) -12 / (signed char) -3 = ...
21062 No, the result is not 4:
21067 (int) (unsigned char) -12 / (int) (signed char) -3 =
21069 (int) (unsigned char) 0xf4 / (int) (signed char) 0xfd =
21071 (int) 0x00f4 / (int) 0xfffd =
21073 (int) 0x00f4 / (int) 0xfffd =
21075 (int) 244 / (int) -3 =
21077 (int) -81 = (int) 0xffaf;
21080 Don't complain, that gcc gives you a different result.
21081 gcc uses 32 bit ints, while SDCC uses 16 bit ints.
21082 Therefore the results are different.
21085 \begin_inset Quotes sld
21089 \begin_inset Quotes srd
21095 If well-defined overflow characteristics are important and negative values
21096 are not, or if you want to steer clear of sign-extension problems when
21097 manipulating bits or bytes, use one of the corresponding unsigned types.
21098 (Beware when mixing signed and unsigned values in expressions, though.)
21100 Although character types (especially unsigned char) can be used as "tiny"
21101 integers, doing so is sometimes more trouble than it's worth, due to unpredicta
21102 ble sign extension and increased code size.
21106 Use unsigned when it is known in advance that the value is not going to
21108 This helps especially if you are doing division or multiplication, bit-shifting
21109 or are using an array index.
21112 NEVER jump into a LOOP.
21115 Declare the variables to be local
21116 \begin_inset LatexCommand \index{local variables}
21120 whenever possible, especially loop control variables (induction).
21123 Since the compiler does not always do implicit integral promotion, the programme
21124 r should do an explicit cast when integral promotion is required.
21127 Reducing the size of division, multiplication & modulus operations can reduce
21128 code size substantially.
21129 Take the following code for example.
21135 foobar(unsigned int p1, unsigned char ch)
21143 unsigned char ch1 = p1 % ch ;
21154 For the modulus operation the variable ch will be promoted to unsigned int
21155 first then the modulus operation will be performed (this will lead to a
21156 call to support routine _moduint()), and the result will be casted to a
21158 If the code is changed to
21163 foobar(unsigned int p1, unsigned char ch)
21171 unsigned char ch1 = (unsigned char)p1 % ch ;
21182 It would substantially reduce the code generated (future versions of the
21183 compiler will be smart enough to detect such optimization opportunities).
21187 Have a look at the assembly listing to get a
21188 \begin_inset Quotes sld
21192 \begin_inset Quotes srd
21195 for the code generation.
21199 \begin_inset LatexCommand \index{Tools}
21203 included in the distribution
21207 \begin_inset Tabular
21208 <lyxtabular version="3" rows="12" columns="3">
21210 <column alignment="center" valignment="top" leftline="true" width="0pt">
21211 <column alignment="center" valignment="top" leftline="true" width="0pt">
21212 <column alignment="left" valignment="top" leftline="true" rightline="true" width="0pt">
21213 <row topline="true" bottomline="true">
21214 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21222 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21230 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21239 <row topline="true">
21240 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21248 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21253 Simulator for various architectures
21256 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21265 <row topline="true">
21266 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21274 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21279 header file conversion
21282 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21287 sdcc/support/scripts
21291 <row topline="true">
21292 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21300 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21305 header file conversion
21308 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21313 sdcc/support/scripts
21317 <row topline="true">
21318 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21326 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21334 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21352 <row topline="true">
21353 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21361 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21369 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21387 <row topline="true">
21388 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21396 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21404 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21422 <row topline="true">
21423 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21431 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21439 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21457 <row topline="true">
21458 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21466 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21474 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21492 <row topline="true">
21493 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21501 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21509 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21527 <row topline="true">
21528 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21536 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21544 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21562 <row topline="true" bottomline="true">
21563 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21571 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21579 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21607 \begin_inset LatexCommand \index{Documentation}
21611 included in the distribution
21615 \begin_inset Tabular
21616 <lyxtabular version="3" rows="10" columns="2">
21618 <column alignment="left" valignment="top" leftline="true" width="0">
21619 <column alignment="left" valignment="top" leftline="true" rightline="true" width="0pt">
21620 <row topline="true" bottomline="true">
21621 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21629 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21634 Where to get / filename
21638 <row topline="true">
21639 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21644 SDCC Compiler User Guide
21647 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21652 You're reading it right now
21656 <row topline="true">
21657 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21665 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21674 <row topline="true">
21675 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21681 \begin_inset LatexCommand \index{asXXXX (as-gbz80, as-hc08, asx8051, as-z80)}
21686 \begin_inset LatexCommand \index{Assembler documentation}
21690 Assemblers and ASLINK
21691 \begin_inset LatexCommand \index{aslink}
21696 \begin_inset LatexCommand \index{Linker documentation}
21703 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21708 sdcc/as/doc/asxhtm.html
21712 <row topline="true">
21713 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21718 SDCC regression test
21719 \begin_inset LatexCommand \index{Regression test}
21726 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21731 sdcc/doc/test_suite_spec.pdf
21735 <row topline="true">
21736 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21744 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21753 <row topline="true">
21754 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21759 Notes on debugging with sdcdb
21760 \begin_inset LatexCommand \index{sdcdb (debugger)}
21767 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21772 sdcc/debugger/README
21776 <row topline="true">
21777 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21782 Software simulator for microcontrollers
21785 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21812 <row topline="true">
21813 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21818 Temporary notes on the pic16
21819 \begin_inset LatexCommand \index{PIC16}
21826 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21831 sdcc/src/pic16/NOTES
21835 <row topline="true" bottomline="true">
21836 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21841 SDCC internal documentation (debugging file format)
21844 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21880 Related open source tools
21881 \begin_inset LatexCommand \index{Related tools}
21889 \begin_inset Tabular
21890 <lyxtabular version="3" rows="11" columns="3">
21892 <column alignment="center" valignment="top" leftline="true" width="0pt">
21893 <column alignment="block" valignment="top" leftline="true" width="30line%">
21894 <column alignment="left" valignment="top" leftline="true" rightline="true" width="0pt">
21895 <row topline="true" bottomline="true">
21896 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21904 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21912 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21921 <row topline="true">
21922 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21928 \begin_inset LatexCommand \index{gpsim (pic simulator)}
21935 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21943 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21949 \begin_inset LatexCommand \url{http://www.dattalo.com/gnupic/gpsim.html}
21957 <row topline="true">
21958 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21964 \begin_inset LatexCommand \index{gputils (pic tools)}
21971 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21979 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21985 \begin_inset LatexCommand \url{http://sourceforge.net/projects/gputils}
21993 <row topline="true">
21994 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22002 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22010 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
22016 \begin_inset LatexCommand \url{http://freshmeat.net/projects/flp5/}
22024 <row topline="true">
22025 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22031 \begin_inset LatexCommand \index{indent (source formatting tool)}
22038 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22043 Formats C source - Master of the white spaces
22046 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
22052 \begin_inset LatexCommand \url{http://directory.fsf.org/GNU/indent.html}
22060 <row topline="true">
22061 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22067 \begin_inset LatexCommand \index{srecord (bin, hex, ... tool)}
22074 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22079 Object file conversion, checksumming, ...
22082 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
22088 \begin_inset LatexCommand \url{http://sourceforge.net/projects/srecord}
22096 <row topline="true">
22097 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22103 \begin_inset LatexCommand \index{objdump (tool)}
22110 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22115 Object file conversion, ...
22118 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
22123 Part of binutils (should be there anyway)
22127 <row topline="true">
22128 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22134 \begin_inset LatexCommand \index{doxygen (source documentation tool)}
22141 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22146 Source code documentation system
22149 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
22155 \begin_inset LatexCommand \url{http://www.doxygen.org}
22163 <row topline="true">
22164 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22172 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22177 IDE (has anyone tried integrating SDCC & sdcdb? Unix only)
22180 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
22186 \begin_inset LatexCommand \url{http://www.kdevelop.org}
22194 <row topline="true">
22195 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22201 \begin_inset LatexCommand \index{splint (syntax checking tool)}
22208 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22213 Statically checks c sources (see
22214 \begin_inset LatexCommand \ref{lyx:more-pedantic-SPLINT}
22221 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
22227 \begin_inset LatexCommand \url{http://www.splint.org}
22235 <row topline="true" bottomline="true">
22236 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22242 \begin_inset LatexCommand \index{ddd (debugger)}
22249 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22254 Debugger, serves nicely as GUI to sdcdb
22255 \begin_inset LatexCommand \index{sdcdb (debugger)}
22262 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
22268 \begin_inset LatexCommand \url{http://www.gnu.org/software/ddd/}
22285 Related documentation / recommended reading
22289 \begin_inset Tabular
22290 <lyxtabular version="3" rows="6" columns="3">
22292 <column alignment="center" valignment="top" leftline="true" width="0pt">
22293 <column alignment="block" valignment="top" leftline="true" width="30line%">
22294 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0pt">
22295 <row topline="true" bottomline="true">
22296 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22304 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22312 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
22321 <row topline="true">
22322 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22339 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22345 \begin_inset LatexCommand \index{C Reference card}
22352 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
22358 \begin_inset LatexCommand \url{http://refcards.com/refcards/c/index.html}
22366 <row topline="true">
22367 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22375 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22383 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
22389 \begin_inset LatexCommand \url{http://www.eskimo.com/~scs/C-faq/top.html}
22397 <row topline="true">
22398 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22405 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22410 Latest datasheet of the target CPU
22413 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
22422 <row topline="true">
22423 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22430 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22435 Revision history of datasheet
22438 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
22447 <row topline="true" bottomline="true">
22448 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22458 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
22463 Advanced Compiler Design and Implementation
22466 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
22471 bookstore (very dedicated, probably read other books first)
22487 Some questions answered, some pointers given - it might be time to in turn
22495 can you solve your project with the selected microcontroller? Would you
22496 find out early or rather late that your target is too small/slow/whatever?
22497 Can you switch to a slightly better device if it doesn't fit?
22500 should you solve the problem with an 8 bit CPU? Or would a 16/32 bit CPU
22501 and/or another programming language be more adequate? Would an operating
22502 system on the target device help?
22505 if you solved the problem, will the marketing department be happy?
22508 if the marketing department is happy, will customers be happy?
22511 if you're the project manager, marketing department and maybe even the customer
22512 in one person, have you tried to see the project from the outside?
22515 is the project done if you think it is done? Or is just that other interface/pro
22516 tocol/feature/configuration/option missing? How about website, manual(s),
22517 internationali(z|s)ation, packaging, labels, 2nd source for components,
22518 electromagnetic compatability/interference, documentation for production,
22519 production test software, update mechanism, patent issues?
22522 is your project adequately positioned in that magic triangle: fame, fortune,
22526 Maybe not all answers to these questions are known and some answers may
22531 , nevertheless knowing these questions may help you to avoid burnout
22537 burnout is bad for electronic devices, programmers and motorcycle tyres
22541 Chances are you didn't want to hear some of them...
22545 \begin_inset LatexCommand \index{Support}
22552 SDCC has grown to be a large project.
22553 The compiler alone (without the preprocessor, assembler and linker) is
22554 well over 100,000 lines of code (blank stripped).
22555 The open source nature of this project is a key to its continued growth
22557 You gain the benefit and support of many active software developers and
22559 Is SDCC perfect? No, that's why we need your help.
22560 The developers take pride in fixing reported bugs.
22561 You can help by reporting the bugs and helping other SDCC users.
22562 There are lots of ways to contribute, and we encourage you to take part
22563 in making SDCC a great software package.
22567 The SDCC project is hosted on the SDCC sourceforge site at
22568 \begin_inset LatexCommand \htmlurl{http://sourceforge.net/projects/sdcc}
22573 You'll find the complete set of mailing lists
22574 \begin_inset LatexCommand \index{Mailing list(s)}
22578 , forums, bug reporting system, patch submission
22579 \begin_inset LatexCommand \index{Patch submission}
22584 \begin_inset LatexCommand \index{download}
22588 area and cvs code repository
22589 \begin_inset LatexCommand \index{cvs code repository}
22597 \begin_inset LatexCommand \index{Bug reporting}
22602 \begin_inset LatexCommand \index{Reporting bugs}
22609 The recommended way of reporting bugs is using the infrastructure of the
22611 You can follow the status of bug reports there and have an overview about
22615 Bug reports are automatically forwarded to the developer mailing list and
22616 will be fixed ASAP.
22617 When reporting a bug, it is very useful to include a small test program
22618 (the smaller the better) which reproduces the problem.
22619 If you can isolate the problem by looking at the generated assembly code,
22620 this can be very helpful.
22621 Compiling your program with the -
22632 \begin_inset LatexCommand \index{-\/-dumpall}
22636 option can sometimes be useful in locating optimization problems.
22637 When reporting a bug please maker sure you:
22640 Attach the code you are compiling with SDCC.
22644 Specify the exact command you use to run SDCC, or attach your Makefile.
22648 Specify the SDCC version (type "
22654 "), your platform, and operating system.
22658 Provide an exact copy of any error message or incorrect output.
22662 Put something meaningful in the subject of your message.
22665 Please attempt to include these 5 important parts, as applicable, in all
22666 requests for support or when reporting any problems or bugs with SDCC.
22667 Though this will make your message lengthy, it will greatly improve your
22668 chance that SDCC users and developers will be able to help you.
22669 Some SDCC developers are frustrated by bug reports without code provided
22670 that they can use to reproduce and ultimately fix the problem, so please
22671 be sure to provide sample code if you are reporting a bug!
22674 Please have a short check that you are using a recent version of SDCC and
22675 the bug is not yet known.
22676 This is the link for reporting bugs:
22677 \begin_inset LatexCommand \htmlurl{http://sourceforge.net/tracker/?group_id=599&atid=100599}
22684 Requesting Features
22685 \begin_inset LatexCommand \label{sub:Requesting-Features}
22690 \begin_inset LatexCommand \index{Feature request}
22695 \begin_inset LatexCommand \index{Requesting features}
22702 Like bug reports feature requests are forwarded to the developer mailing
22704 This is the link for requesting features:
22705 \begin_inset LatexCommand \htmlurl{http://sourceforge.net/tracker/?group_id=599&atid=350599}
22715 Like bug reports contributed patches are forwarded to the developer mailing
22717 This is the link for submitting patches
22718 \begin_inset LatexCommand \index{Patch submission}
22723 \begin_inset LatexCommand \url{http://sourceforge.net/tracker/?group_id=599&atid=300599}
22730 You need to specify some parameters to the
22734 command for the patches to be useful.
22735 If you modified more than one file a patch created f.e.
22740 \begin_inset Quotes sld
22743 diff -Naur unmodified_directory modified_directory >my_changes.patch
22744 \begin_inset Quotes srd
22750 will be fine, otherwise
22754 \begin_inset Quotes sld
22757 diff -u sourcefile.c.orig sourcefile.c >my_changes.patch
22758 \begin_inset Quotes srd
22771 These links should take you directly to the
22772 \begin_inset LatexCommand \url[Mailing lists]{http://sourceforge.net/mail/?group_id=599}
22782 Traffic on sdcc-devel and sdcc-user is about 100 mails/month each not counting
22783 automated messages (mid 2003)
22787 \begin_inset LatexCommand \url[Forums]{http://sourceforge.net/forum/?group_id=599}
22792 \begin_inset LatexCommand \index{Mailing list(s)}
22796 and forums are archived and searchable so if you are lucky someone already
22797 had a similar problem.
22798 While mails to the lists themselves are delivered promptly their web front
22799 end on sourceforge sometimes shows a severe time lag (up to several weeks),
22800 if you're seriously using SDCC please consider subscribing to the lists.
22806 You can follow the status of the cvs version
22807 \begin_inset LatexCommand \index{version}
22811 of SDCC by watching the Changelog
22812 \begin_inset LatexCommand \index{Changelog}
22816 in the cvs-repository
22821 \begin_inset LatexCommand \htmlurl{http://cvs.sf.net/cgi-bin/viewcvs.cgi/*checkout*/sdcc/sdcc/ChangeLog?rev=HEAD&content-type=text/plain}
22829 \begin_inset LatexCommand \index{Release policy}
22836 Historically there often were long delays between official releases and
22837 the sourceforge download area tends to get not updated at all.
22838 Excuses in the past might have referred to problems with live range analysis,
22839 but as this was fixed a while ago, the current problem is that another
22840 excuse has to be found.
22841 Kidding aside, we have to get better there! On the other hand there are
22842 daily snapshots available at
22843 \begin_inset LatexCommand \htmlurl[snap]{http://sdcc.sourceforge.net/snap.php}
22847 , and you can always build the very last version (hopefully with many bugs
22848 fixed, and features added) from the source code available at
22849 \begin_inset LatexCommand \htmlurl[Source]{http://sdcc.sourceforge.net/snap.php#Source}
22857 \begin_inset LatexCommand \index{Examples}
22864 You'll find some small examples in the directory
22866 sdcc/device/examples/.
22869 More examples and libraries are available at
22871 The SDCC Open Knowledge Resource
22872 \begin_inset LatexCommand \url{http://sdccokr.dl9sec.de/}
22879 \begin_inset LatexCommand \url{http://www.pjrc.com/tech/8051/}
22886 I did insert a reference to Paul's web site here although it seems rather
22887 dedicated to a specific 8032 board (I think it's okay because it f.e.
22888 shows LCD/Harddisc interface and has a free 8051 monitor.
22889 Independent 8032 board vendors face hard competition of heavily subsidized
22890 development boards anyway).
22893 Maybe we should include some links to real world applications.
22894 Preferably pointer to pointers (one for each architecture) so this stays
22899 \begin_inset LatexCommand \index{Quality control}
22906 The compiler is passed through nightly compile and build checks.
22912 \begin_inset LatexCommand \index{Regression test}
22916 check that SDCC itself compiles flawlessly on several platforms and checks
22917 the quality of the code generated by SDCC by running the code through simulator
22919 There is a separate document
22922 \begin_inset LatexCommand \index{Test suite}
22931 You'll find the test code in the directory
22933 sdcc/support/regression
22936 You can run these tests manually by running
22940 in this directory (or f.e.
22945 \begin_inset Quotes sld
22949 \begin_inset Quotes srd
22955 if you don't want to run the complete tests).
22956 The test code might also be interesting if you want to look for examples
22957 \begin_inset LatexCommand \index{Examples}
22961 checking corner cases of SDCC or if you plan to submit patches
22962 \begin_inset LatexCommand \index{Patch submission}
22969 The pic port uses a different set of regression tests, you'll find them
22972 sdcc/src/regression
22977 SDCC Technical Data
22981 \begin_inset LatexCommand \index{Optimizations}
22988 SDCC performs a host of standard optimizations in addition to some MCU specific
22993 Sub-expression Elimination
22994 \begin_inset LatexCommand \index{Subexpression elimination}
23001 The compiler does local and
23027 will be translated to
23039 Some subexpressions are not as obvious as the above example, e.g.:
23049 In this case the address arithmetic a->b[i] will be computed only once;
23050 the equivalent code in C would be.
23062 The compiler will try to keep these temporary variables in registers.
23065 Dead-Code Elimination
23066 \begin_inset LatexCommand \index{Dead-code elimination}
23087 i = 1; \SpecialChar ~
23096 global = 1;\SpecialChar ~
23109 global = 3;\SpecialChar ~
23134 \begin_inset LatexCommand \index{Copy propagation}
23190 Note: the dead stores created by this copy propagation will be eliminated
23191 by dead-code elimination.
23195 \begin_inset LatexCommand \index{Loop optimization}
23200 \begin_inset LatexCommand \label{sub:Loop-Optimizations}
23207 Two types of loop optimizations are done by SDCC
23215 of loop induction variables.
23216 In addition to the strength reduction the optimizer marks the induction
23217 variables and the register allocator tries to keep the induction variables
23218 in registers for the duration of the loop.
23219 Because of this preference of the register allocator
23220 \begin_inset LatexCommand \index{Register allocation}
23224 , loop induction optimization causes an increase in register pressure, which
23225 may cause unwanted spilling of other temporary variables into the stack
23226 \begin_inset LatexCommand \index{stack}
23231 The compiler will generate a warning message when it is forced to allocate
23232 extra space either on the stack or data space.
23233 If this extra space allocation is undesirable then induction optimization
23234 can be eliminated either for the entire source file (with -
23244 -noinduction option) or for a given function only using #pragma\SpecialChar ~
23246 \begin_inset LatexCommand \index{\#pragma noinduction}
23259 for (i = 0 ; i < 100 ; i ++)
23275 for (i = 0; i < 100; i++)
23284 As mentioned previously some loop invariants are not as apparent, all static
23285 address computations are also moved out of the loop.
23290 \begin_inset LatexCommand \index{Strength reduction}
23294 , this optimization substitutes an expression by a cheaper expression:
23299 for (i=0;i < 100; i++)
23317 for (i=0;i< 100;i++) {
23323 ar[itemp1] = itemp2;
23340 The more expensive multiplication
23341 \begin_inset LatexCommand \index{Multiplication}
23345 is changed to a less expensive addition.
23349 \begin_inset LatexCommand \index{Loop reversing}
23356 This optimization is done to reduce the overhead of checking loop boundaries
23357 for every iteration.
23358 Some simple loops can be reversed and implemented using a
23359 \begin_inset Quotes eld
23362 decrement and jump if not zero
23363 \begin_inset Quotes erd
23367 SDCC checks for the following criterion to determine if a loop is reversible
23368 (note: more sophisticated compilers use data-dependency analysis to make
23369 this determination, SDCC uses a more simple minded analysis).
23372 The 'for' loop is of the form
23378 for(<symbol> = <expression>; <sym> [< | <=] <expression>; [<sym>++ | <sym>
23388 The <for body> does not contain
23389 \begin_inset Quotes eld
23393 \begin_inset Quotes erd
23397 \begin_inset Quotes erd
23403 All goto's are contained within the loop.
23406 No function calls within the loop.
23409 The loop control variable <sym> is not assigned any value within the loop
23412 The loop control variable does NOT participate in any arithmetic operation
23416 There are NO switch statements in the loop.
23419 Algebraic Simplifications
23422 SDCC does numerous algebraic simplifications, the following is a small sub-set
23423 of these optimizations.
23428 i = j + 0;\SpecialChar ~
23432 /* changed to: */\SpecialChar ~
23438 i /= 2;\SpecialChar ~
23445 /* changed to: */\SpecialChar ~
23451 i = j - j;\SpecialChar ~
23455 /* changed to: */\SpecialChar ~
23461 i = j / 1;\SpecialChar ~
23465 /* changed to: */\SpecialChar ~
23472 Note the subexpressions
23473 \begin_inset LatexCommand \index{Subexpression}
23477 given above are generally introduced by macro expansions or as a result
23478 of copy/constant propagation.
23481 'switch' Statements
23482 \begin_inset LatexCommand \label{sub:'switch'-Statements}
23487 \begin_inset LatexCommand \index{switch statement}
23494 SDCC can optimize switch statements to jump tables
23495 \begin_inset LatexCommand \index{jump tables}
23500 It makes the decision based on an estimate of the generated code size.
23501 SDCC is quite liberal in the requirements for jump table generation:
23504 The labels need not be in order, and the starting number need not be one
23505 or zero, the case labels are in numerical sequence or not too many case
23506 labels are missing.
23512 switch(i) {\SpecialChar ~
23543 case 4: ...\SpecialChar ~
23575 case 5: ...\SpecialChar ~
23607 case 3: ...\SpecialChar ~
23638 case 6: ...\SpecialChar ~
23670 case 7: ...\SpecialChar ~
23702 case 8: ...\SpecialChar ~
23734 case 9: ...\SpecialChar ~
23766 case 10: ...\SpecialChar ~
23797 case 11: ...\SpecialChar ~
23864 Both the above switch statements will be implemented using a jump-table.
23865 The example to the right side is slightly more efficient as the check for
23866 the lower boundary of the jump-table is not needed.
23870 The number of case labels is not larger than supported by the target architectur
23874 If the case labels are not in numerical sequence ('gaps' between cases)
23875 SDCC checks whether a jump table with additionally inserted dummy cases
23876 is still attractive.
23880 If the starting number is not zero and a check for the lower boundary of
23881 the jump-table can thus be eliminated SDCC might insert dummy cases 0,
23886 Switch statements which have large gaps in the numeric sequence or those
23887 that have too many case labels can be split into more than one switch statement
23888 for efficient code generation, e.g.:
23968 If the above switch statement is broken down into two switch statements
24058 then both the switch statements will be implemented using jump-tables whereas
24059 the unmodified switch statement will not be.
24062 There might be reasons which SDCC cannot know about to either favour or
24063 not favour jump tables.
24064 If the target system has to be as quick for the last switch case as for
24065 the first (pro jump table), or if the switch argument is known to be zero
24066 in the majority of the cases (contra jump table).
24069 The pragma nojtbound
24070 \begin_inset LatexCommand \index{\#pragma nojtbound}
24074 can be used to turn off checking the
24087 It has no effect if a default label is supplied.
24088 Use of this pragma is dangerous: if the switch
24089 \begin_inset LatexCommand \index{switch statement}
24093 argument is not matched by a case statement the processor will happily
24097 Bit-shifting Operations
24098 \begin_inset LatexCommand \index{Bit shifting}
24105 Bit shifting is one of the most frequently used operation in embedded programmin
24107 SDCC tries to implement bit-shift operations in the most efficient way
24123 generates the following code:
24140 In general SDCC will never setup a loop if the shift count is known.
24183 \begin_inset LatexCommand \index{Bit rotation}
24190 A special case of the bit-shift operation is bit rotation
24191 \begin_inset LatexCommand \index{rotating bits}
24195 , SDCC recognizes the following expression to be a left bit-rotation:
24205 char i;\SpecialChar ~
24216 /* unsigned is needed for rotation */
24221 i = ((i << 1) | (i >> 7));
24230 will generate the following code:
24249 SDCC uses pattern matching on the parse tree to determine this operation.Variatio
24250 ns of this case will also be recognized as bit-rotation, i.e.:
24255 i = ((i >> 7) | (i << 1)); /* left-bit rotation */
24258 Nibble and Byte Swapping
24261 Other special cases of the bit-shift operations are nibble or byte swapping
24262 \begin_inset LatexCommand \index{swapping nibbles/bytes}
24266 , SDCC recognizes the following expressions:
24289 i = ((i << 4) | (i >> 4));
24295 j = ((j << 8) | (j >> 8));
24298 and generates a swap instruction for the nibble swapping
24299 \begin_inset LatexCommand \index{Nibble swapping}
24303 or move instructions for the byte swapping
24304 \begin_inset LatexCommand \index{Byte swapping}
24310 \begin_inset Quotes sld
24314 \begin_inset Quotes srd
24317 example can be used to convert from little to big-endian or vice versa.
24318 If you want to change the endianness of a
24322 integer you have to cast to
24329 Note that SDCC stores numbers in little-endian
24335 Usually 8-bit processors don't care much about endianness.
24336 This is not the case for the standard 8051 which only has an instruction
24342 \begin_inset LatexCommand \index{DPTR}
24350 so little-endian is the more efficient byte order.
24354 \begin_inset LatexCommand \index{little-endian}
24359 \begin_inset LatexCommand \index{Endianness}
24364 lowest order first).
24368 \begin_inset LatexCommand \index{Highest Order Bit}
24375 It is frequently required to obtain the highest order bit of an integral
24376 type (long, int, short or char types).
24377 SDCC recognizes the following expression to yield the highest order bit
24378 and generates optimized code for it, e.g.:
24400 hob = (gint >> 15) & 1;
24410 will generate the following code:
24443 000A E5*01\SpecialChar ~
24470 000C 23\SpecialChar ~
24501 000D 54 01\SpecialChar ~
24528 000F F5*02\SpecialChar ~
24556 Variations of this case however will
24561 It is a standard C expression, so I heartily recommend this be the only
24562 way to get the highest order bit, (it is portable).
24563 Of course it will be recognized even if it is embedded in other expressions,
24569 xyz = gint + ((gint >> 15) & 1);
24572 will still be recognized.
24576 \begin_inset LatexCommand \label{sub:Peephole-Optimizer}
24581 \begin_inset LatexCommand \index{Peephole optimizer}
24588 The compiler uses a rule based, pattern matching and re-writing mechanism
24589 for peep-hole optimization.
24594 a peep-hole optimizer by Christopher W.
24595 Fraser (cwfraser\SpecialChar ~
24598 A default set of rules are compiled into the compiler, additional rules
24599 may be added with the
24612 \begin_inset LatexCommand \index{-\/-peep-file}
24619 The rule language is best illustrated with examples.
24643 The above rule will change the following assembly
24644 \begin_inset LatexCommand \index{Assembler routines}
24666 Note: All occurrences of a
24670 (pattern variable) must denote the same string.
24671 With the above rule, the assembly sequence:
24681 will remain unmodified.
24685 Other special case optimizations may be added by the user (via
24701 some variants of the 8051 MCU
24702 \begin_inset LatexCommand \index{MCS51 variants}
24715 The following two rules will change all
24734 replace { lcall %1 } by { acall %1 }
24736 replace { ljmp %1 } by { ajmp %1 }
24741 inline-assembler code
24743 is also passed through the peep hole optimizer, thus the peephole optimizer
24744 can also be used as an assembly level macro expander.
24745 The rules themselves are MCU dependent whereas the rule language infra-structur
24746 e is MCU independent.
24747 Peephole optimization rules for other MCU can be easily programmed using
24752 The syntax for a rule is as follows:
24757 rule := replace [ restart ] '{' <assembly sequence> '
24795 <assembly sequence> '
24813 '}' [if <functionName> ] '
24818 <assembly sequence> := assembly instruction (each instruction including
24819 labels must be on a separate line).
24823 The optimizer will apply to the rules one by one from the top in the sequence
24824 of their appearance, it will terminate when all rules are exhausted.
24825 If the 'restart' option is specified, then the optimizer will start matching
24826 the rules again from the top, this option for a rule is expensive (performance)
24827 , it is intended to be used in situations where a transformation will trigger
24828 the same rule again.
24829 An example of this (not a good one, it has side effects) is the following
24852 Note that the replace pattern cannot be a blank, but can be a comment line.
24853 Without the 'restart' option only the innermost 'pop' 'push' pair would
24854 be eliminated, i.e.:
24884 the restart option the rule will be applied again to the resulting code
24885 and then all the pop-push pairs will be eliminated to yield:
24895 A conditional function can be attached to a rule.
24896 Attaching rules are somewhat more involved, let me illustrate this with
24923 The optimizer does a look-up of a function name table defined in function
24928 in the source file SDCCpeeph.c, with the name
24933 If it finds a corresponding entry the function is called.
24934 Note there can be no parameters specified for these functions, in this
24939 is crucial, since the function
24943 expects to find the label in that particular variable (the hash table containin
24944 g the variable bindings is passed as a parameter).
24945 If you want to code more such functions, take a close look at the function
24946 labelInRange and the calling mechanism in source file SDCCpeeph.c.
24947 Currently implemented are
24949 labelInRange, labelRefCount, labelIsReturnOnly, operandsNotSame, xramMovcOption,
24950 24bitMode, portIsDS390, 24bitModeAndPortDS390
24959 I know this whole thing is a little kludgey, but maybe some day we will
24960 have some better means.
24961 If you are looking at this file, you will see the default rules that are
24962 compiled into the compiler, you can add your own rules in the default set
24963 there if you get tired of specifying the -
24977 \begin_inset LatexCommand \index{ANSI-compliance}
24982 \begin_inset LatexCommand \label{sub:ANSI-Compliance}
24989 Deviations from the compliance:
24992 functions are not reentrant
24993 \begin_inset LatexCommand \index{reentrant}
24997 unless explicitly declared as such or the
25010 \begin_inset LatexCommand \index{-\/-stack-auto}
25016 command line option is specified.
25019 structures and unions cannot be assigned values directly, cannot be passed
25020 as function parameters or assigned to each other and cannot be a return
25021 value from a function, e.g.:
25047 s1 = s2 ; /* is invalid in SDCC although allowed in ANSI */
25058 struct s foo1 (struct s parms) /* invalid in SDCC although allowed in ANSI
25080 return rets;/* is invalid in SDCC although allowed in ANSI */
25087 \begin_inset LatexCommand \index{long long (not supported)}
25092 \begin_inset LatexCommand \index{int (64 bit) (not supported)}
25100 \begin_inset LatexCommand \index{double (not supported)}
25104 ' precision floating point
25105 \begin_inset LatexCommand \index{Floating point support}
25112 No support for setjmp
25113 \begin_inset LatexCommand \index{setjmp (not supported)}
25118 \begin_inset LatexCommand \index{longjmp (not supported)}
25126 \begin_inset LatexCommand \index{K\&R style}
25130 function declarations are NOT allowed.
25136 foo(i,j) /* this old style of function declarations */
25138 int i,j; /* are valid in ANSI but not valid in SDCC */
25153 Certain words that are valid identifiers in the standard may be reserved
25154 words in SDCC unless the
25167 \begin_inset LatexCommand \index{-\/-std-c89}
25182 \begin_inset LatexCommand \index{-\/-std-c99}
25188 command line options are used.
25189 These may include (depending on the selected processor): 'at', 'banked',
25190 'bit', 'code', 'critical', 'data', 'eeprom', 'far', 'flash', 'idata', 'interrup
25191 t', 'near', 'nonbanked', 'pdata', 'reentrant', 'sbit', 'sfr', 'shadowregs',
25192 'sram', 'using', 'wparam', 'xdata', '_overlay', '_asm', '_endasm', and
25194 Compliant equivalents of these keywords are always available in a form
25195 that begin with two underscores
25196 \begin_inset LatexCommand \index{\_\_ (prefix for extended keywords)}
25201 '__data' instead of 'data'.
25204 Cyclomatic Complexity
25205 \begin_inset LatexCommand \index{Cyclomatic complexity}
25212 Cyclomatic complexity of a function is defined as the number of independent
25213 paths the program can take during execution of the function.
25214 This is an important number since it defines the number test cases you
25215 have to generate to validate the function.
25216 The accepted industry standard for complexity number is 10, if the cyclomatic
25217 complexity reported by SDCC exceeds 10 you should think about simplification
25218 of the function logic.
25219 Note that the complexity level is not related to the number of lines of
25220 code in a function.
25221 Large functions can have low complexity, and small functions can have large
25227 SDCC uses the following formula to compute the complexity:
25232 complexity = (number of edges in control flow graph) - (number of nodes
25233 in control flow graph) + 2;
25237 Having said that the industry standard is 10, you should be aware that in
25238 some cases it be may unavoidable to have a complexity level of less than
25240 For example if you have switch statement with more than 10 case labels,
25241 each case label adds one to the complexity level.
25242 The complexity level is by no means an absolute measure of the algorithmic
25243 complexity of the function, it does however provide a good starting point
25244 for which functions you might look at for further optimization.
25247 Retargetting for other Processors
25250 The issues for retargetting the compiler are far too numerous to be covered
25252 What follows is a brief description of each of the seven phases of the
25253 compiler and its MCU dependency.
25256 Parsing the source and building the annotated parse tree.
25257 This phase is largely MCU independent (except for the language extensions).
25258 Syntax & semantic checks are also done in this phase, along with some initial
25259 optimizations like back patching labels and the pattern matching optimizations
25260 like bit-rotation etc.
25263 The second phase involves generating an intermediate code which can be easy
25264 manipulated during the later phases.
25265 This phase is entirely MCU independent.
25266 The intermediate code generation assumes the target machine has unlimited
25267 number of registers, and designates them with the name iTemp.
25268 The compiler can be made to dump a human readable form of the code generated
25282 This phase does the bulk of the standard optimizations and is also MCU independe
25284 This phase can be broken down into several sub-phases:
25288 Break down intermediate code (iCode) into basic blocks.
25290 Do control flow & data flow analysis on the basic blocks.
25292 Do local common subexpression elimination, then global subexpression elimination
25294 Dead code elimination
25298 If loop optimizations caused any changes then do 'global subexpression eliminati
25299 on' and 'dead code elimination' again.
25302 This phase determines the live-ranges; by live range I mean those iTemp
25303 variables defined by the compiler that still survive after all the optimization
25305 Live range analysis
25306 \begin_inset LatexCommand \index{Live range analysis}
25310 is essential for register allocation, since these computation determines
25311 which of these iTemps will be assigned to registers, and for how long.
25314 Phase five is register allocation.
25315 There are two parts to this process.
25319 The first part I call 'register packing' (for lack of a better term).
25320 In this case several MCU specific expression folding is done to reduce
25325 The second part is more MCU independent and deals with allocating registers
25326 to the remaining live ranges.
25327 A lot of MCU specific code does creep into this phase because of the limited
25328 number of index registers available in the 8051.
25331 The Code generation phase is (unhappily), entirely MCU dependent and very
25332 little (if any at all) of this code can be reused for other MCU.
25333 However the scheme for allocating a homogenized assembler operand for each
25334 iCode operand may be reused.
25337 As mentioned in the optimization section the peep-hole optimizer is rule
25338 based system, which can reprogrammed for other MCUs.
25342 \begin_inset LatexCommand \index{Compiler internals}
25349 The anatomy of the compiler
25350 \begin_inset LatexCommand \label{sub:The-anatomy-of}
25359 This is an excerpt from an article published in Circuit Cellar Magazine
25365 It's a little outdated (the compiler is much more efficient now and user/develo
25366 per friendly), but pretty well exposes the guts of it all.
25372 The current version of SDCC can generate code for Intel 8051 and Z80 MCU.
25373 It is fairly easy to retarget for other 8-bit MCU.
25374 Here we take a look at some of the internals of the compiler.
25379 \begin_inset LatexCommand \index{Parsing}
25386 Parsing the input source file and creating an AST (Annotated Syntax Tree
25387 \begin_inset LatexCommand \index{Annotated syntax tree}
25392 This phase also involves propagating types (annotating each node of the
25393 parse tree with type information) and semantic analysis.
25394 There are some MCU specific parsing rules.
25395 For example the storage classes, the extended storage classes are MCU specific
25396 while there may be a xdata storage class for 8051 there is no such storage
25397 class for z80 or Atmel AVR.
25398 SDCC allows MCU specific storage class extensions, i.e.
25399 xdata will be treated as a storage class specifier when parsing 8051 C
25400 code but will be treated as a C identifier when parsing z80 or ATMEL AVR
25405 \begin_inset LatexCommand \index{iCode}
25412 Intermediate code generation.
25413 In this phase the AST is broken down into three-operand form (iCode).
25414 These three operand forms are represented as doubly linked lists.
25415 ICode is the term given to the intermediate form generated by the compiler.
25416 ICode example section shows some examples of iCode generated for some simple
25417 C source functions.
25421 \begin_inset LatexCommand \index{Optimizations}
25428 Bulk of the target independent optimizations is performed in this phase.
25429 The optimizations include constant propagation, common sub-expression eliminati
25430 on, loop invariant code movement, strength reduction of loop induction variables
25431 and dead-code elimination.
25434 Live range analysis
25435 \begin_inset LatexCommand \index{Live range analysis}
25442 During intermediate code generation phase, the compiler assumes the target
25443 machine has infinite number of registers and generates a lot of temporary
25445 The live range computation determines the lifetime of each of these compiler-ge
25446 nerated temporaries.
25447 A picture speaks a thousand words.
25448 ICode example sections show the live range annotations for each of the
25450 It is important to note here, each iCode is assigned a number in the order
25451 of its execution in the function.
25452 The live ranges are computed in terms of these numbers.
25453 The from number is the number of the iCode which first defines the operand
25454 and the to number signifies the iCode which uses this operand last.
25457 Register Allocation
25458 \begin_inset LatexCommand \index{Register allocation}
25465 The register allocation determines the type and number of registers needed
25467 In most MCUs only a few registers can be used for indirect addressing.
25468 In case of 8051 for example the registers R0 & R1 can be used to indirectly
25469 address the internal ram and DPTR to indirectly address the external ram.
25470 The compiler will try to allocate the appropriate register to pointer variables
25472 ICode example section shows the operands annotated with the registers assigned
25474 The compiler will try to keep operands in registers as much as possible;
25475 there are several schemes the compiler uses to do achieve this.
25476 When the compiler runs out of registers the compiler will check to see
25477 if there are any live operands which is not used or defined in the current
25478 basic block being processed, if there are any found then it will push that
25479 operand and use the registers in this block, the operand will then be popped
25480 at the end of the basic block.
25484 There are other MCU specific considerations in this phase.
25485 Some MCUs have an accumulator; very short-lived operands could be assigned
25486 to the accumulator instead of a general-purpose register.
25492 Figure II gives a table of iCode operations supported by the compiler.
25493 The code generation involves translating these operations into corresponding
25494 assembly code for the processor.
25495 This sounds overly simple but that is the essence of code generation.
25496 Some of the iCode operations are generated on a MCU specific manner for
25497 example, the z80 port does not use registers to pass parameters so the
25498 SEND and RECV iCode operations will not be generated, and it also does
25499 not support JUMPTABLES.
25506 <Where is Figure II?>
25509 In the original article Figure II was announced to be downloadable on
25514 Unfortunately it never seemed to have shown up there, so: where is Figure
25519 \begin_inset LatexCommand \index{iCode}
25526 This section shows some details of iCode.
25527 The example C code does not do anything useful; it is used as an example
25528 to illustrate the intermediate code generated by the compiler.
25540 /* This function does nothing useful.
25547 for the purpose of explaining iCode */
25550 short function (data int *x)
25558 short i=10; \SpecialChar ~
25560 /* dead initialization eliminated */
25565 short sum=10; /* dead initialization eliminated */
25578 while (*x) *x++ = *p++;
25592 /* compiler detects i,j to be induction variables */
25596 for (i = 0, j = 10 ; i < 10 ; i++, j
25622 mul += i * 3; \SpecialChar ~
25624 /* this multiplication remains */
25630 gint += j * 3;\SpecialChar ~
25632 /* this multiplication changed to addition */
25646 In addition to the operands each iCode contains information about the filename
25647 and line it corresponds to in the source file.
25648 The first field in the listing should be interpreted as follows:
25653 Filename(linenumber: iCode Execution sequence number : ICode hash table
25654 key : loop depth of the iCode).
25659 Then follows the human readable form of the ICode operation.
25660 Each operand of this triplet form can be of three basic types a) compiler
25661 generated temporary b) user defined variable c) a constant value.
25662 Note that local variables and parameters are replaced by compiler generated
25665 \begin_inset LatexCommand \index{Live range analysis}
25669 are computed only for temporaries (i.e.
25670 live ranges are not computed for global variables).
25672 \begin_inset LatexCommand \index{Register allocation}
25676 are allocated for temporaries only.
25677 Operands are formatted in the following manner:
25682 Operand Name [lr live-from : live-to ] { type information } [ registers
25688 As mentioned earlier the live ranges are computed in terms of the execution
25689 sequence number of the iCodes, for example
25691 the iTemp0 is live from (i.e.
25692 first defined in iCode with execution sequence number 3, and is last used
25693 in the iCode with sequence number 5).
25694 For induction variables such as iTemp21 the live range computation extends
25695 the lifetime from the start to the end of the loop.
25697 The register allocator used the live range information to allocate registers,
25698 the same registers may be used for different temporaries if their live
25699 ranges do not overlap, for example r0 is allocated to both iTemp6 and to
25700 iTemp17 since their live ranges do not overlap.
25701 In addition the allocator also takes into consideration the type and usage
25702 of a temporary, for example itemp6 is a pointer to near space and is used
25703 as to fetch data from (i.e.
25704 used in GET_VALUE_AT_ADDRESS) so it is allocated a pointer register (r0).
25705 Some short lived temporaries are allocated to special registers which have
25706 meaning to the code generator e.g.
25707 iTemp13 is allocated to a pseudo register CC which tells the back end that
25708 the temporary is used only for a conditional jump the code generation makes
25709 use of this information to optimize a compare and jump ICode.
25711 There are several loop optimizations
25712 \begin_inset LatexCommand \index{Loop optimization}
25716 performed by the compiler.
25717 It can detect induction variables iTemp21(i) and iTemp23(j).
25718 Also note the compiler does selective strength reduction
25719 \begin_inset LatexCommand \index{Strength reduction}
25724 the multiplication of an induction variable in line 18 (gint = j * 3) is
25725 changed to addition, a new temporary iTemp17 is allocated and assigned
25726 a initial value, a constant 3 is then added for each iteration of the loop.
25727 The compiler does not change the multiplication
25728 \begin_inset LatexCommand \index{Multiplication}
25732 in line 17 however since the processor does support an 8 * 8 bit multiplication.
25734 Note the dead code elimination
25735 \begin_inset LatexCommand \index{Dead-code elimination}
25739 optimization eliminated the dead assignments in line 7 & 8 to I and sum
25747 Sample.c (5:1:0:0) _entry($9) :
25752 Sample.c(5:2:1:0) proc _function [lr0:0]{function short}
25757 Sample.c(11:3:2:0) iTemp0 [lr3:5]{_near * int}[r2] = recv
25762 Sample.c(11:4:53:0) preHeaderLbl0($11) :
25767 Sample.c(11:5:55:0) iTemp6 [lr5:16]{_near * int}[r0] := iTemp0 [lr3:5]{_near
25773 Sample.c(11:6:5:1) _whilecontinue_0($1) :
25778 Sample.c(11:7:7:1) iTemp4 [lr7:8]{int}[r2 r3] = @[iTemp6 [lr5:16]{_near *
25784 Sample.c(11:8:8:1) if iTemp4 [lr7:8]{int}[r2 r3] == 0 goto _whilebreak_0($3)
25789 Sample.c(11:9:14:1) iTemp7 [lr9:13]{_far * int}[DPTR] := _p [lr0:0]{_far
25795 Sample.c(11:10:15:1) _p [lr0:0]{_far * int} = _p [lr0:0]{_far * int} + 0x2
25801 Sample.c(11:13:18:1) iTemp10 [lr13:14]{int}[r2 r3] = @[iTemp7 [lr9:13]{_far
25807 Sample.c(11:14:19:1) *(iTemp6 [lr5:16]{_near * int}[r0]) := iTemp10 [lr13:14]{int
25813 Sample.c(11:15:12:1) iTemp6 [lr5:16]{_near * int}[r0] = iTemp6 [lr5:16]{_near
25814 * int}[r0] + 0x2 {short}
25819 Sample.c(11:16:20:1) goto _whilecontinue_0($1)
25824 Sample.c(11:17:21:0)_whilebreak_0($3) :
25829 Sample.c(12:18:22:0) iTemp2 [lr18:40]{short}[r2] := 0x0 {short}
25834 Sample.c(13:19:23:0) iTemp11 [lr19:40]{short}[r3] := 0x0 {short}
25839 Sample.c(15:20:54:0)preHeaderLbl1($13) :
25844 Sample.c(15:21:56:0) iTemp21 [lr21:38]{short}[r4] := 0x0 {short}
25849 Sample.c(15:22:57:0) iTemp23 [lr22:38]{int}[r5 r6] := 0xa {int}
25854 Sample.c(15:23:58:0) iTemp17 [lr23:38]{int}[r7 r0] := 0x1e {int}
25859 Sample.c(15:24:26:1)_forcond_0($4) :
25864 Sample.c(15:25:27:1) iTemp13 [lr25:26]{char}[CC] = iTemp21 [lr21:38]{short}[r4]
25870 Sample.c(15:26:28:1) if iTemp13 [lr25:26]{char}[CC] == 0 goto _forbreak_0($7)
25875 Sample.c(16:27:31:1) iTemp2 [lr18:40]{short}[r2] = iTemp2 [lr18:40]{short}[r2]
25876 + ITemp21 [lr21:38]{short}[r4]
25881 Sample.c(17:29:33:1) iTemp15 [lr29:30]{short}[r1] = iTemp21 [lr21:38]{short}[r4]
25887 Sample.c(17:30:34:1) iTemp11 [lr19:40]{short}[r3] = iTemp11 [lr19:40]{short}[r3]
25888 + iTemp15 [lr29:30]{short}[r1]
25893 Sample.c(18:32:36:1:1) iTemp17 [lr23:38]{int}[r7 r0]= iTemp17 [lr23:38]{int}[r7
25899 Sample.c(18:33:37:1) _gint [lr0:0]{int} = _gint [lr0:0]{int} + iTemp17 [lr23:38]{
25905 Sample.c(15:36:42:1) iTemp21 [lr21:38]{short}[r4] = iTemp21 [lr21:38]{short}[r4]
25911 Sample.c(15:37:45:1) iTemp23 [lr22:38]{int}[r5 r6]= iTemp23 [lr22:38]{int}[r5
25917 Sample.c(19:38:47:1) goto _forcond_0($4)
25922 Sample.c(19:39:48:0)_forbreak_0($7) :
25927 Sample.c(20:40:49:0) iTemp24 [lr40:41]{short}[DPTR] = iTemp2 [lr18:40]{short}[r2]
25928 + ITemp11 [lr19:40]{short}[r3]
25933 Sample.c(20:41:50:0) ret iTemp24 [lr40:41]{short}
25938 Sample.c(20:42:51:0)_return($8) :
25943 Sample.c(20:43:52:0) eproc _function [lr0:0]{ ia0 re0 rm0}{function short}
25949 Finally the code generated for this function:
25990 ; ----------------------------------------------
25995 ; function function
26000 ; ----------------------------------------------
26010 ; iTemp0 [lr3:5]{_near * int}[r2] = recv
26022 ; iTemp6 [lr5:16]{_near * int}[r0] := iTemp0 [lr3:5]{_near * int}[r2]
26034 ;_whilecontinue_0($1) :
26044 ; iTemp4 [lr7:8]{int}[r2 r3] = @[iTemp6 [lr5:16]{_near * int}[r0]]
26049 ; if iTemp4 [lr7:8]{int}[r2 r3] == 0 goto _whilebreak_0($3)
26108 ; iTemp7 [lr9:13]{_far * int}[DPTR] := _p [lr0:0]{_far * int}
26127 ; _p [lr0:0]{_far * int} = _p [lr0:0]{_far * int} + 0x2 {short}
26174 ; iTemp10 [lr13:14]{int}[r2 r3] = @[iTemp7 [lr9:13]{_far * int}[DPTR]]
26214 ; *(iTemp6 [lr5:16]{_near * int}[r0]) := iTemp10 [lr13:14]{int}[r2 r3]
26240 ; iTemp6 [lr5:16]{_near * int}[r0] =
26245 ; iTemp6 [lr5:16]{_near * int}[r0] +
26262 ; goto _whilecontinue_0($1)
26274 ; _whilebreak_0($3) :
26284 ; iTemp2 [lr18:40]{short}[r2] := 0x0 {short}
26296 ; iTemp11 [lr19:40]{short}[r3] := 0x0 {short}
26308 ; iTemp21 [lr21:38]{short}[r4] := 0x0 {short}
26320 ; iTemp23 [lr22:38]{int}[r5 r6] := 0xa {int}
26339 ; iTemp17 [lr23:38]{int}[r7 r0] := 0x1e {int}
26368 ; iTemp13 [lr25:26]{char}[CC] = iTemp21 [lr21:38]{short}[r4] < 0xa {short}
26373 ; if iTemp13 [lr25:26]{char}[CC] == 0 goto _forbreak_0($7)
26418 ; iTemp2 [lr18:40]{short}[r2] = iTemp2 [lr18:40]{short}[r2] +
26423 ; iTemp21 [lr21:38]{short}[r4]
26449 ; iTemp15 [lr29:30]{short}[r1] = iTemp21 [lr21:38]{short}[r4] * 0x3 {short}
26482 ; iTemp11 [lr19:40]{short}[r3] = iTemp11 [lr19:40]{short}[r3] +
26487 ; iTemp15 [lr29:30]{short}[r1]
26506 ; iTemp17 [lr23:38]{int}[r7 r0]= iTemp17 [lr23:38]{int}[r7 r0]- 0x3 {short}
26553 ; _gint [lr0:0]{int} = _gint [lr0:0]{int} + iTemp17 [lr23:38]{int}[r7 r0]
26600 ; iTemp21 [lr21:38]{short}[r4] = iTemp21 [lr21:38]{short}[r4] + 0x1 {short}
26612 ; iTemp23 [lr22:38]{int}[r5 r6]= iTemp23 [lr22:38]{int}[r5 r6]- 0x1 {short}
26626 cjne r5,#0xff,00104$
26638 ; goto _forcond_0($4)
26650 ; _forbreak_0($7) :
26660 ; ret iTemp24 [lr40:41]{short}
26703 A few words about basic block successors, predecessors and dominators
26706 Successors are basic blocks
26707 \begin_inset LatexCommand \index{Basic blocks}
26711 that might execute after this basic block.
26713 Predecessors are basic blocks that might execute before reaching this basic
26716 Dominators are basic blocks that WILL execute before reaching this basic
26750 a) succList of [BB2] = [BB4], of [BB3] = [BB4], of [BB1] = [BB2,BB3]
26753 b) predList of [BB2] = [BB1], of [BB3] = [BB1], of [BB4] = [BB2,BB3]
26756 c) domVect of [BB4] = BB1 ...
26757 here we are not sure if BB2 or BB3 was executed but we are SURE that BB1
26765 \begin_inset LatexCommand \url{http://sdcc.sourceforge.net#Who}
26775 Thanks to all the other volunteer developers who have helped with coding,
26776 testing, web-page creation, distribution sets, etc.
26777 You know who you are :-)
26784 This document was initially written by Sandeep Dutta
26787 All product names mentioned herein may be trademarks
26788 \begin_inset LatexCommand \index{Trademarks}
26792 of their respective companies.
26799 To avoid confusion, the installation and building options for SDCC itself
26800 (chapter 2) are not part of the index.
26804 \begin_inset LatexCommand \printindex{}