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={68hc08 8032 8051 ansi c compiler assembler CPU DS390 embedded development free Floating Point Arithmetic Freescale GPL HC08 inline Intel ISO/IEC 9899:1990 Linux MAC OS X manual Maxim mcs51 Microchip microcontroller open source PIC Unix Windows Z80 Zilog},
11 pdfpagemode=UseOutlines,
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 Subversion
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 retargeted for other microprocessors, support for Microchip PIC,
146 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 retargetable 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:
209 <lyxtabular version="3" rows="8" columns="5">
211 <column alignment="center" valignment="top" leftline="true" width="0">
212 <column alignment="center" valignment="top" leftline="true" width="0">
213 <column alignment="center" valignment="top" leftline="true" width="0">
214 <column alignment="center" valignment="top" leftline="true" width="0">
215 <column alignment="block" valignment="top" leftline="true" rightline="true" width="20text%">
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217 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
225 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
233 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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259 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
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291 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
301 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
309 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
317 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
325 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
333 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
343 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
351 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
359 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
367 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
375 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
385 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
393 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
401 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
409 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
417 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
426 <row topline="true" bottomline="true">
427 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
435 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
443 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
451 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
456 -2.147.483.648, +2.147.483.647
459 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
468 <row topline="true" bottomline="true">
469 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
477 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
485 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
493 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
500 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
518 <row topline="true" bottomline="true">
519 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
527 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
535 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
543 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
550 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
564 The compiler also allows
566 inline assembler code
568 to be embedded anywhere in a function.
569 In addition, routines developed in assembly can also be called.
573 SDCC also provides an option (-
583 -cyclomatic) to report the relative complexity of a function.
584 These functions can then be further optimized, or hand coded in assembly
590 SDCC also comes with a companion source level debugger SDCDB, the debugger
591 currently uses ucSim a freeware simulator for 8051 and other micro-controllers.<
595 The latest version can be downloaded from
596 \begin_inset LatexCommand \url{http://sdcc.sourceforge.net/snap.php}
606 Please note: the compiler will probably always be some steps ahead of this
611 \begin_inset LatexCommand \index{Status of documentation}
621 Obviously this has pros and cons
630 All packages used in this compiler system are
638 ; source code for all the sub-packages (pre-processor, assemblers, linkers
639 etc) is distributed with the package.
640 This documentation is maintained using a freeware word processor (LyX).
642 This program is free software; you can redistribute it and/or modify it
643 under the terms of the GNU General Public License
644 \begin_inset LatexCommand \index{GNU General Public License, GPL}
648 as published by the Free Software Foundation; either version 2, or (at
649 your option) any later version.
650 This program is distributed in the hope that it will be useful, but WITHOUT
651 ANY WARRANTY; without even the implied warranty
652 \begin_inset LatexCommand \index{warranty}
656 of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
657 See the GNU General Public License for more details.
658 You should have received a copy of the GNU General Public License along
659 with this program; if not, write to the Free Software Foundation, 59 Temple
660 Place - Suite 330, Boston, MA 02111-1307, USA.
661 In other words, you are welcome to use, share and improve this program.
662 You are forbidden to forbid anyone else to use, share and improve what
664 Help stamp out software-hoarding!
667 Typographic conventions
668 \begin_inset LatexCommand \index{Typographic conventions}
675 Throughout this manual, we will use the following convention.
676 Commands you have to type in are printed in
684 Code samples are printed in
689 Interesting items and new terms are printed in
695 \begin_inset LatexCommand \label{sec:Compatibility-with-previous}
699 with previous versions
700 \begin_inset LatexCommand \index{Compatibility with previous versions}
707 This version has numerous bug fixes compared with the previous version.
708 But we also introduced some incompatibilities with older versions.
709 Not just for the fun of it, but to make the compiler more stable, efficient
711 \begin_inset LatexCommand \index{ANSI-compliance}
716 \begin_inset LatexCommand \ref{sub:ANSI-Compliance}
720 for ANSI-Compliance).
726 short is now equivalent to int (16 bits), it used to be equivalent to char
727 (8 bits) which is not ANSI compliant.
730 the default directory for gcc-builds where include, library and documentation
731 files are stored is now in /usr/local/share.
734 char type parameters to vararg
735 \begin_inset LatexCommand \index{vararg, va\_arg}
739 functions are casted to int unless explicitly casted
740 \begin_inset Marginal
767 will push a as an int and as a char resp.
780 -regextend has been removed.
793 -noregparms has been removed.
806 -stack-after-data has been removed.
810 \begin_inset LatexCommand \index{bit}
815 \begin_inset LatexCommand \index{sbit}
820 \begin_inset LatexCommand \index{\_\_sbit}
824 types now consistently behave like the C99 _Bool type with respect to type
826 \begin_inset LatexCommand \index{type conversion}
831 \begin_inset LatexCommand \index{type promotion}
836 The most common incompatibility resulting from this change is related to
838 \begin_inset LatexCommand \index{Bit toggling}
853 \begin_inset LatexCommand \index{\~\/ Operator}
857 b; /* equivalent to b=1 instead of toggling b */
858 \begin_inset Marginal
873 b = !b; /* toggles b */
877 In previous versions, both forms would have toggled the bit.
882 <pending: more incompatibilities?>
888 What do you need before you start installation of SDCC? A computer, and
890 The preferred method of installation is to compile SDCC from source using
892 For Windows some pre-compiled binary distributions are available for your
894 You should have some experience with command line tools and compiler use.
900 The SDCC home page at
901 \begin_inset LatexCommand \url{http://sdcc.sourceforge.net/}
905 is a great place to find distribution sets.
906 You can also find links to the user mailing lists that offer help or discuss
907 SDCC with other SDCC users.
908 Web links to other SDCC related sites can also be found here.
909 This document can be found in the DOC directory of the source package as
911 A pdf version of this document is available at
912 \begin_inset LatexCommand \url{http://sdcc.sourceforge.net/doc/sdccman.pdf}
917 Some of the other tools (simulator and assembler) included with SDCC contain
918 their own documentation and can be found in the source distribution.
919 If you want the latest unreleased software, the complete source package
920 is available directly from Subversion on https://svn.sourceforge.net/svnroot/sdcc
924 Wishes for the future
927 There are (and always will be) some things that could be done.
928 Here are some I can think of:
935 char KernelFunction3(char p) at 0x340;
943 \begin_inset LatexCommand \index{code banking (limited support)}
953 If you can think of some more, please see the section
954 \begin_inset LatexCommand \ref{sub:Requesting-Features}
958 about filing feature requests
959 \begin_inset LatexCommand \index{Requesting features}
964 \begin_inset LatexCommand \index{Feature request}
974 \begin_inset LatexCommand \index{Installation}
981 For most users it is sufficient to skip to either section
982 \begin_inset LatexCommand \ref{sub:Building-SDCC-on-Linux}
987 \begin_inset LatexCommand \ref{sub:Windows-Install}
992 More detailed instructions follow below.
996 \begin_inset LatexCommand \index{Options SDCC configuration}
1003 The install paths, search paths and other options are defined when running
1005 The defaults can be overridden by:
1007 \labelwidthstring 00.00.0000
1019 -prefix see table below
1021 \labelwidthstring 00.00.0000
1033 -exec_prefix see table below
1035 \labelwidthstring 00.00.0000
1047 -bindir see table below
1049 \labelwidthstring 00.00.0000
1061 -datadir see table below
1065 \labelwidthstring 00.00.0000
1069 docdir environment variable, see table below
1071 \labelwidthstring 00.00.0000
1075 include_dir_suffix environment variable, see table below
1077 \labelwidthstring 00.00.0000
1081 lib_dir_suffix environment variable, see table below
1083 \labelwidthstring 00.00.0000
1087 sdccconf_h_dir_separator environment variable, either / or
1092 This character will only be used in sdccconf.h; don't forget it's a C-header,
1093 therefore a double-backslash is needed there.
1097 \labelwidthstring 00.00.0000
1109 -disable-mcs51-port Excludes the Intel mcs51 port
1111 \labelwidthstring 00.00.0000
1123 -disable-gbz80-port Excludes the Gameboy gbz80 port
1125 \labelwidthstring 00.00.0000
1137 -disable-z80-port Excludes the z80 port
1139 \labelwidthstring 00.00.0000
1151 -disable-avr-port Excludes the AVR port
1153 \labelwidthstring 00.00.0000
1165 -disable-ds390-port Excludes the DS390 port
1167 \labelwidthstring 00.00.0000
1179 -disable-hc08-port Excludes the HC08 port
1181 \labelwidthstring 00.00.0000
1193 -disable-pic-port Excludes the PIC port
1195 \labelwidthstring 00.00.0000
1207 -disable-xa51-port Excludes the XA51 port
1209 \labelwidthstring 00.00.0000
1221 -disable-ucsim Disables configuring and building of ucsim
1223 \labelwidthstring 00.00.0000
1235 -disable-device-lib Disables automatically building device libraries
1237 \labelwidthstring 00.00.0000
1249 -disable-packihx Disables building packihx
1253 \labelwidthstring 00.00.0000
1265 -enable-doc Build pdf, html and txt files from the lyx sources
1267 \labelwidthstring 00.00.0000
1279 -enable-libgc Use the Bohem memory allocator.
1280 Lower runtime footprint.
1283 Furthermore the environment variables CC, CFLAGS, ...
1284 the tools and their arguments can be influenced.
1285 Please see `configure -
1295 -help` and the man/info pages of `configure` for details.
1299 The names of the standard libraries STD_LIB, STD_INT_LIB, STD_LONG_LIB,
1300 STD_FP_LIB, STD_DS390_LIB, STD_XA51_LIB and the environment variables SDCC_DIR_
1301 NAME, SDCC_INCLUDE_NAME, SDCC_LIB_NAME are defined by `configure` too.
1302 At the moment it's not possible to change the default settings (it was
1303 simply never required).
1307 These configure options are compiled into the binaries, and can only be
1308 changed by rerunning 'configure' and recompiling SDCC.
1309 The configure options are written in
1313 to distinguish them from run time environment variables (see section search
1319 \begin_inset Quotes sld
1323 \begin_inset Quotes srd
1326 are used by the SDCC team to build the official Win32 binaries.
1327 The SDCC team uses Mingw32 to build the official Windows binaries, because
1334 a gcc compiler and last but not least
1337 the binaries can be built by cross compiling on Sourceforge's compile farm.
1340 See the examples, how to pass the Win32 settings to 'configure'.
1341 The other Win32 builds using Borland, VC or whatever don't use 'configure',
1342 but a header file sdcc_vc_in.h is the same as sdccconf.h built by 'configure'
1353 \begin_inset Tabular
1354 <lyxtabular version="3" rows="8" columns="3">
1356 <column alignment="block" valignment="top" leftline="true" width="0in">
1357 <column alignment="block" valignment="top" leftline="true" width="0in">
1358 <column alignment="block" valignment="top" leftline="true" rightline="true" width="0in">
1359 <row topline="true" bottomline="true">
1360 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1368 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1376 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1385 <row topline="true">
1386 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1396 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1404 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1415 <row topline="true">
1416 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1426 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1436 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1447 <row topline="true">
1448 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1458 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1470 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1485 <row topline="true">
1486 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1496 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1508 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1519 <row topline="true">
1520 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1530 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1542 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1557 <row topline="true">
1558 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1568 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1576 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1585 <row topline="true" bottomline="true">
1586 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1596 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1604 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1622 'configure' also computes relative paths.
1623 This is needed for full relocatability of a binary package and to complete
1624 search paths (see section search paths below):
1630 \begin_inset Tabular
1631 <lyxtabular version="3" rows="4" columns="3">
1633 <column alignment="block" valignment="top" leftline="true" width="0in">
1634 <column alignment="block" valignment="top" leftline="true" width="0in">
1635 <column alignment="block" valignment="top" leftline="true" rightline="true" width="0in">
1636 <row topline="true" bottomline="true">
1637 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1645 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1653 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1662 <row topline="true" bottomline="true">
1663 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1673 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1681 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1690 <row bottomline="true">
1691 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1701 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1709 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1718 <row bottomline="true">
1719 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1729 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
1737 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
1770 \begin_inset Quotes srd
1774 \begin_inset Quotes srd
1788 \begin_inset Quotes srd
1792 \begin_inset Quotes srd
1820 To cross compile on linux for Mingw32 (see also 'sdcc/support/scripts/sdcc_mingw
1829 \begin_inset Quotes srd
1832 i586-mingw32msvc-gcc
1833 \begin_inset Quotes srd
1837 \begin_inset Quotes srd
1840 i586-mingw32msvc-g++
1841 \begin_inset Quotes srd
1849 \begin_inset Quotes srd
1852 i586-mingw32msvc-ranlib
1853 \begin_inset Quotes srd
1861 \begin_inset Quotes srd
1864 i586-mingw32msvc-strip
1865 \begin_inset Quotes srd
1883 \begin_inset Quotes srd
1887 \begin_inset Quotes srd
1905 \begin_inset Quotes srd
1909 \begin_inset Quotes srd
1917 \begin_inset Quotes srd
1921 \begin_inset Quotes srd
1929 \begin_inset Quotes srd
1933 \begin_inset Quotes srd
1941 \begin_inset Quotes srd
1945 \begin_inset Quotes srd
1952 sdccconf_h_dir_separator=
1953 \begin_inset Quotes srd
1965 \begin_inset Quotes srd
1996 -host=i586-mingw32msvc
2010 -build=unknown-unknown-linux-gnu
2014 \begin_inset Quotes sld
2018 \begin_inset Quotes srd
2021 compile on Cygwin for Mingw32 (see also sdcc/support/scripts/sdcc_cygwin_mingw32
2040 \begin_inset Quotes srd
2044 \begin_inset Quotes srd
2062 \begin_inset Quotes srd
2066 \begin_inset Quotes srd
2074 \begin_inset Quotes srd
2078 \begin_inset Quotes srd
2086 \begin_inset Quotes srd
2090 \begin_inset Quotes srd
2098 \begin_inset Quotes srd
2102 \begin_inset Quotes srd
2109 sdccconf_h_dir_separator=
2110 \begin_inset Quotes srd
2122 \begin_inset Quotes srd
2130 \begin_inset Quotes srd
2134 \begin_inset Quotes srd
2142 \begin_inset Quotes srd
2146 \begin_inset Quotes srd
2152 'configure' is quite slow on Cygwin (at least on windows before Win2000/XP).
2163 -C' turns on caching, which gives a little bit extra speed.
2164 However if options are changed, it can be necessary to delete the config.cache
2169 \begin_inset LatexCommand \label{sub:Install-paths}
2174 \begin_inset LatexCommand \index{Install paths}
2180 \added_space_top medskip \align center
2182 \begin_inset Tabular
2183 <lyxtabular version="3" rows="5" columns="4">
2185 <column alignment="left" valignment="top" leftline="true" width="0">
2186 <column alignment="left" valignment="top" leftline="true" width="0">
2187 <column alignment="left" valignment="top" leftline="true" width="0">
2188 <column alignment="left" valignment="top" leftline="true" rightline="true" width="0">
2189 <row topline="true" bottomline="true">
2190 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2200 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2210 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2220 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2231 <row topline="true">
2232 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2240 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2250 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2258 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2271 <row topline="true">
2272 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2280 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2287 $DATADIR/ $INCLUDE_DIR_SUFFIX
2290 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2295 /usr/local/share/sdcc/include
2298 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2311 <row topline="true">
2312 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2320 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2327 $DATADIR/$LIB_DIR_SUFFIX
2330 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2335 /usr/local/share/sdcc/lib
2338 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2351 <row topline="true" bottomline="true">
2352 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2360 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2370 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2375 /usr/local/share/sdcc/doc
2378 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2400 *compiler, preprocessor, assembler, and linker
2406 is auto-appended by the compiler, e.g.
2407 small, large, z80, ds390 etc
2410 The install paths can still be changed during `make install` with e.g.:
2413 make install prefix=$(HOME)/local/sdcc
2416 Of course this doesn't change the search paths compiled into the binaries.
2420 Moreover the install path can be changed by defining DESTDIR
2421 \begin_inset LatexCommand \index{DESTDIR}
2428 make install DESTDIR=$(HOME)/sdcc.rpm/
2431 Please note that DESTDIR must have a trailing slash!
2435 \begin_inset LatexCommand \label{sub:Search-Paths}
2440 \begin_inset LatexCommand \index{Search path}
2447 Some search paths or parts of them are determined by configure variables
2452 , see section above).
2453 Further search paths are determined by environment variables during runtime.
2456 The paths searched when running the compiler are as follows (the first catch
2462 Binary files (preprocessor, assembler and linker)
2468 \begin_inset Tabular
2469 <lyxtabular version="3" rows="4" columns="3">
2471 <column alignment="block" valignment="top" leftline="true" width="0in">
2472 <column alignment="block" valignment="top" leftline="true" width="0in">
2473 <column alignment="block" valignment="top" leftline="true" rightline="true" width="0in">
2474 <row topline="true" bottomline="true">
2475 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2483 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2491 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2500 <row topline="true">
2501 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2511 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2519 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2530 <row topline="true">
2531 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2536 Path of argv[0] (if available)
2539 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2547 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2556 <row topline="true" bottomline="true">
2557 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2565 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2573 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2598 \begin_inset Tabular
2599 <lyxtabular version="3" rows="6" columns="3">
2601 <column alignment="block" valignment="top" leftline="true" width="1.5in">
2602 <column alignment="block" valignment="top" leftline="true" width="1.5in">
2603 <column alignment="block" valignment="top" leftline="true" rightline="true" width="0in">
2604 <row topline="true" bottomline="true">
2605 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2613 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2621 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2630 <row topline="true">
2631 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2649 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2667 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2686 <row topline="true">
2687 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2695 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2703 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2712 <row topline="true">
2713 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2727 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2739 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2750 <row topline="true">
2751 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2769 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2819 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2832 <row topline="true" bottomline="true">
2833 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2849 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2854 /usr/local/share/sdcc/
2859 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2887 -nostdinc disables the last two search paths.
2897 With the exception of
2898 \begin_inset Quotes sld
2912 \begin_inset Quotes srd
2919 is auto-appended by the compiler (e.g.
2920 small, large, z80, ds390 etc.).
2927 \begin_inset Tabular
2928 <lyxtabular version="3" rows="6" columns="3">
2930 <column alignment="block" valignment="top" leftline="true" width="1.7in">
2931 <column alignment="block" valignment="top" leftline="true" width="1.2in">
2932 <column alignment="block" valignment="top" leftline="true" rightline="true" width="1.2in">
2933 <row topline="true" bottomline="true">
2934 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2942 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2950 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
2959 <row topline="true">
2960 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
2978 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
2996 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
3015 <row topline="true">
3016 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
3028 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
3040 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
3055 <row topline="true">
3056 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
3067 $LIB_DIR_SUFFIX/<model>
3070 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
3084 <cell alignment="left" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
3101 <row topline="true">
3102 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
3117 $LIB_DIR_SUFFIX/<model>
3120 <cell alignment="left" valignment="top" topline="true" leftline="true" usebox="none">
3173 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
3229 <row topline="true" bottomline="true">
3230 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
3239 $LIB_DIR_SUFFIX/<model>
3242 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
3247 /usr/local/share/sdcc/
3254 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
3272 Don't delete any of the stray spaces in the table above without checking
3273 the HTML output (last line)!
3289 -nostdlib disables the last two search paths.
3293 \begin_inset LatexCommand \index{Building SDCC}
3300 Building SDCC on Linux
3301 \begin_inset LatexCommand \label{sub:Building-SDCC-on-Linux}
3310 Download the source package
3312 either from the SDCC Subversion repository or from the nightly snapshots
3314 , it will be named something like sdcc
3325 \begin_inset LatexCommand \url{http://sdcc.sourceforge.net/snap.php}
3334 Bring up a command line terminal, such as xterm.
3339 Unpack the file using a command like:
3342 "tar -xvzf sdcc.src.tar.gz
3347 , this will create a sub-directory called sdcc with all of the sources.
3350 Change directory into the main SDCC directory, for example type:
3367 This configures the package for compilation on your system.
3383 All of the source packages will compile, this can take a while.
3399 This copies the binary executables, the include files, the libraries and
3400 the documentation to the install directories.
3401 Proceed with section
3402 \begin_inset LatexCommand \ref{sec:Testing-the-SDCC}
3409 Building SDCC on OSX 2.x
3412 Follow the instruction for Linux.
3416 On OSX 2.x it was reported, that the default gcc (version 3.1 20020420 (prerelease
3417 )) fails to compile SDCC.
3418 Fortunately there's also gcc 2.9.x installed, which works fine.
3419 This compiler can be selected by running 'configure' with:
3422 ./configure CC=gcc2 CXX=g++2
3425 Cross compiling SDCC on Linux for Windows
3428 With the Mingw32 gcc cross compiler it's easy to compile SDCC for Win32.
3429 See section 'Configure Options'.
3432 Building SDCC using Cygwin and Mingw32
3435 For building and installing a Cygwin executable follow the instructions
3441 \begin_inset Quotes sld
3445 \begin_inset Quotes srd
3448 Win32-binary can be built, which will not need the Cygwin-DLL.
3449 For the necessary 'configure' options see section 'configure options' or
3450 the script 'sdcc/support/scripts/sdcc_cygwin_mingw32'.
3454 In order to install Cygwin on Windows download setup.exe from
3455 \begin_inset LatexCommand \url[www.cygwin.com]{http://www.cygwin.com/}
3461 \begin_inset Quotes sld
3464 default text file type
3465 \begin_inset Quotes srd
3469 \begin_inset Quotes sld
3473 \begin_inset Quotes srd
3476 and download/install at least the following packages.
3477 Some packages are selected by default, others will be automatically selected
3478 because of dependencies with the manually selected packages.
3479 Never deselect these packages!
3488 gcc ; version 3.x is fine, no need to use the old 2.9x
3491 binutils ; selected with gcc
3497 rxvt ; a nice console, which makes life much easier under windoze (see below)
3500 man ; not really needed for building SDCC, but you'll miss it sooner or
3504 less ; not really needed for building SDCC, but you'll miss it sooner or
3508 svn ; only if you use Subversion access
3511 If you want to develop something you'll need:
3514 python ; for the regression tests
3517 gdb ; the gnu debugger, together with the nice GUI
3518 \begin_inset Quotes sld
3522 \begin_inset Quotes srd
3528 openssh ; to access the CF or commit changes
3531 autoconf and autoconf-devel ; if you want to fight with 'configure', don't
3532 use autoconf-stable!
3535 rxvt is a nice console with history.
3536 Replace in your cygwin.bat the line
3555 rxvt -sl 1000 -fn "Lucida Console-12" -sr -cr red
3558 -bg black -fg white -geometry 100x65 -e bash -
3571 Text selected with the mouse is automatically copied to the clipboard, pasting
3572 works with shift-insert.
3576 The other good tip is to make sure you have no //c/-style paths anywhere,
3577 use /cygdrive/c/ instead.
3578 Using // invokes a network lookup which is very slow.
3580 \begin_inset Quotes sld
3584 \begin_inset Quotes srd
3587 is too long, you can change it with e.g.
3593 SDCC sources use the unix line ending LF.
3594 Life is much easier, if you store the source tree on a drive which is mounted
3596 And use an editor which can handle LF-only line endings.
3597 Make sure not to commit files with windows line endings.
3598 The tabulator spacing
3599 \begin_inset LatexCommand \index{tabulator spacing (8 columns)}
3603 used in the project is 8.
3604 Although a tabulator spacing of 8 is a sensible choice for programmers
3605 (it's a power of 2 and allows to display 8/16 bit signed variables without
3606 loosing columns) the plan is to move towards using only spaces in the source.
3609 Building SDCC Using Microsoft Visual C++ 6.0/NET (MSVC)
3614 Download the source package
3616 either from the SDCC Subversion repository or from the
3617 \begin_inset LatexCommand \url[nightly snapshots]{http://sdcc.sourceforge.net/snap.php}
3623 , it will be named something like sdcc
3630 SDCC is distributed with all the projects, workspaces, and files you need
3631 to build it using Visual C++ 6.0/NET (except for SDCDB and ucSim).
3632 The workspace name is 'sdcc.dsw'.
3633 Please note that as it is now, all the executables are created in a folder
3637 Once built you need to copy the executables from sdcc
3641 bin before running SDCC.
3646 WARNING: Visual studio is very picky with line terminations; it expects
3647 the 0x0d, 0x0a DOS style line endings, not the 0x0a Unix style line endings.
3648 When using the Subversion repository it's easiest to configure the svn
3649 client to convert automatically for you.
3650 If however you are getting a message such as "This makefile was not generated
3651 by Developer Studio etc.
3653 \begin_inset Quotes srd
3656 when opening the sdcc.dsw workspace or any of the *.dsp projects, then you
3657 need to convert the Unix style line endings to DOS style line endings.
3658 To do so you can use the
3659 \begin_inset Quotes sld
3663 \begin_inset Quotes srd
3666 utility freely available on the internet.
3667 Doug Hawkins reported in the sdcc-user list that this works:
3675 SDCC> unix2dos sdcc.dsw
3681 SDCC> for /R %I in (*.dsp) do @unix2dos "%I"
3685 In order to build SDCC with MSVC you need win32 executables of bison.exe,
3686 flex.exe, and gawk.exe.
3687 One good place to get them is
3688 \begin_inset LatexCommand \url[here]{http://unxutils.sourceforge.net}
3696 Download the file UnxUtils
3697 \begin_inset LatexCommand \index{UnxUtils}
3702 Now you have to install the utilities and setup MSVC so it can locate the
3704 Here there are two alternatives (choose one!):
3711 a) Extract UnxUtils.zip to your C:
3713 hard disk PRESERVING the original paths, otherwise bison won't work.
3714 (If you are using WinZip make certain that 'Use folder names' is selected)
3718 b) In the Visual C++ IDE click Tools, Options, select the Directory tab,
3719 in 'Show directories for:' select 'Executable files', and in the directories
3720 window add a new path: 'C:
3730 (As a side effect, you get a bunch of Unix utilities that could be useful,
3731 such as diff and patch.)
3738 This one avoids extracting a bunch of files you may not use, but requires
3743 a) Create a directory were to put the tools needed, or use a directory already
3751 b) Extract 'bison.exe', 'bison.hairy', 'bison.simple', 'flex.exe', and gawk.exe
3752 to such directory WITHOUT preserving the original paths.
3753 (If you are using WinZip make certain that 'Use folder names' is not selected)
3757 c) Rename bison.exe to '_bison.exe'.
3761 d) Create a batch file 'bison.bat' in 'C:
3765 ' and add these lines:
3785 _bison %1 %2 %3 %4 %5 %6 %7 %8 %9
3789 Steps 'c' and 'd' are needed because bison requires by default that the
3790 files 'bison.simple' and 'bison.hairy' reside in some weird Unix directory,
3791 '/usr/local/share/' I think.
3792 So it is necessary to tell bison where those files are located if they
3793 are not in such directory.
3794 That is the function of the environment variables BISON_SIMPLE and BISON_HAIRY.
3798 e) In the Visual C++ IDE click Tools, Options, select the Directory tab,
3799 in 'Show directories for:' select 'Executable files', and in the directories
3800 window add a new path: 'c:
3803 Note that you can use any other path instead of 'c:
3805 util', even the path where the Visual C++ tools are, probably: 'C:
3809 Microsoft Visual Studio
3814 So you don't have to execute step 'e' :)
3818 Open 'sdcc.dsw' in Visual Studio, click 'build all', when it finishes copy
3819 the executables from sdcc
3823 bin, and you can compile using SDCC.
3826 Building SDCC Using Borland
3829 From the sdcc directory, run the command "make -f Makefile.bcc".
3830 This should regenerate all the .exe files in the bin directory except for
3834 If you modify any source files and need to rebuild, be aware that the dependenci
3835 es may not be correctly calculated.
3836 The safest option is to delete all .obj files and run the build again.
3837 From a Cygwin BASH prompt, this can easily be done with the command (be
3838 sure you are in the sdcc directory):
3848 ( -name '*.obj' -o -name '*.lib' -o -name '*.rul'
3850 ) -print -exec rm {}
3859 or on Windows NT/2000/XP from the command prompt with the command:
3866 del /s *.obj *.lib *.rul
3869 from the sdcc directory.
3872 Windows Install Using a ZIP Package
3875 Download the binary zip package from
3876 \begin_inset LatexCommand \url{http://sdcc.sf.net/snap.php}
3880 and unpack it using your favorite unpacking tool (gunzip, WinZip, etc).
3881 This should unpack to a group of sub-directories.
3882 An example directory structure after unpacking the mingw32 package is:
3887 bin for the executables, c:
3895 lib for the include and libraries.
3898 Adjust your environment variable PATH to include the location of the bin
3899 directory or start sdcc using the full path.
3902 Windows Install Using the Setup Program
3903 \begin_inset LatexCommand \label{sub:Windows-Install}
3910 Download the setup program
3912 sdcc-x.y.z-setup.exe
3914 for an official release from
3917 \begin_inset LatexCommand \url{http://sf.net/project/showfiles.php?group_id=599}
3921 or a setup program for one of the snapshots
3923 sdcc-yyyymmdd-xxxx-setup.exe
3926 \begin_inset LatexCommand \url{http://sdcc.sf.net/snap.php}
3931 A windows typical installer will guide you through the installation process.
3935 \begin_inset LatexCommand \index{VPATH}
3942 SDCC supports the VPATH feature provided by configure and make.
3943 It allows to separate the source and build trees.
3975 tar -xzf sdcc.src.tar.gz\SpecialChar ~
3976 # extract source to directory sdcc
3981 mkdir sdcc.build\SpecialChar ~
3990 # put output in sdcc.build
4000 ../sdcc/configure\SpecialChar ~
4008 # configure is doing all the magic!
4020 will create the directory tree will all the necessary Makefiles in ~/sdcc.build.
4021 It automagically computes the variables srcdir, top_srcdir and top_buildir
4027 the generated files will be in ~/sdcc.build, while the source files stay
4030 This is not only usefull for building different binaries, e.g.
4031 when cross compiling.
4032 It also gives you a much better overview in the source tree when all the
4033 generated files are not scattered between the source files.
4034 And the best thing is: if you want to change a file you can leave the original
4035 file untouched in the source directory.
4036 Simply copy it to the build directory, edit it, enter `make clean`, `rm
4037 Makefile.dep` and `make`.
4042 will do the rest for you!
4045 Building the Documentation
4058 -enable-doc to the configure arguments to build the documentation together
4059 with all the other stuff.
4060 You will need several tools (LyX, LaTeX, LaTeX2HTML, pdflatex, dvipdf,
4061 dvips and makeindex) to get the job done.
4062 Another possibility is to change to the doc directory and to type
4066 \begin_inset Quotes srd
4070 \begin_inset Quotes srd
4077 You're invited to make changes and additions to this manual (sdcc/doc/sdccman.ly
4080 \begin_inset LatexCommand \url{http://www.lyx.org}
4084 as editor is straightforward.
4085 Prebuilt documentation in html and pdf format is available from
4086 \begin_inset LatexCommand \url{http://sdcc.sf.net/snap.php}
4093 Reading the Documentation
4094 \begin_inset LatexCommand \index{Documentation}
4101 Currently reading the document in pdf format is recommended, as for unknown
4102 reason the hyperlinks are working there whereas in the html version they
4109 If you should know why please drop us a note
4115 You'll find the pdf version
4116 \begin_inset LatexCommand \index{PDF version of this document}
4121 \begin_inset LatexCommand \url{http://sdcc.sf.net/doc/sdccman.pdf}
4129 \begin_inset LatexCommand \index{HTML version of this document}
4134 \begin_inset LatexCommand \url{http://sdcc.sf.net/doc/sdccman.html/index.html}
4140 This documentation is in some aspects different from a commercial documentation:
4144 It tries to document SDCC for several processor architectures in one document
4145 (commercially these probably would be separate documents/products).
4147 \begin_inset LatexCommand \index{Status of documentation}
4151 currently matches SDCC for mcs51 and DS390 best and does give too few informati
4153 Z80, PIC14, PIC16 and HC08.
4156 There are many references pointing away from this documentation.
4157 Don't let this distract you.
4159 was a reference like
4160 \begin_inset LatexCommand \url{http://www.opencores.org}
4164 together with a statement
4165 \begin_inset Quotes sld
4168 some processors which are targetted by SDCC can be implemented in a
4185 \begin_inset LatexCommand \index{FPGA (field programmable gate array)}
4190 \begin_inset Quotes srd
4194 \begin_inset LatexCommand \url{http://sf.net/projects/fpgac}
4199 \begin_inset LatexCommand \index{FpgaC ((subset of) C to FPGA compiler)}
4204 \begin_inset Quotes sld
4207 have you ever heard of an open source compiler that compiles a subset of
4209 \begin_inset Quotes srd
4212 we expect you to have a quick look there and come back.
4213 If you read this you are on the right track.
4216 Some sections attribute more space to problems, restrictions and warnings
4217 than to the solution.
4220 The installation section and the section about the debugger is intimidating.
4223 There are still lots of typos and there are more different writing styles
4227 Testing the SDCC Compiler
4228 \begin_inset LatexCommand \label{sec:Testing-the-SDCC}
4235 The first thing you should do after installing your SDCC compiler is to
4251 \begin_inset LatexCommand \index{version}
4258 at the prompt, and the program should run and output its version like:
4263 SDCC : mcs51/z80/avr/ds390/pic16/pic14/ds400/hc08 2.5.6 #4169 (May 8 2006)
4267 If it doesn't run, or gives a message about not finding sdcc program, then
4268 you need to check over your installation.
4269 Make sure that the sdcc bin directory is in your executable search path
4270 defined by the PATH environment setting (
4275 \begin_inset LatexCommand \ref{sub:Install-Trouble-shooting}
4282 Install trouble-shooting for suggestions
4285 Make sure that the sdcc program is in the bin folder, if not perhaps something
4286 did not install correctly.
4294 is commonly installed as described in section
4295 \begin_inset Quotes sld
4298 Install and search paths
4299 \begin_inset Quotes srd
4308 Make sure the compiler works on a very simple example.
4309 Type in the following test.c program using your favorite
4335 Compile this using the following command:
4344 If all goes well, the compiler will generate a test.asm and test.rel file.
4345 Congratulations, you've just compiled your first program with SDCC.
4346 We used the -c option to tell SDCC not to link the generated code, just
4347 to keep things simple for this step.
4355 The next step is to try it with the linker.
4365 If all goes well the compiler will link with the libraries and produce
4366 a test.ihx output file.
4371 (no test.ihx, and the linker generates warnings), then the problem is most
4380 usr/local/share/sdcc/lib directory
4387 \begin_inset LatexCommand \ref{sub:Install-Trouble-shooting}
4394 Install trouble-shooting for suggestions).
4402 The final test is to ensure
4410 header files and libraries.
4411 Edit test.c and change it to the following:
4428 strcpy(str1, "testing");
4435 Compile this by typing
4442 This should generate a test.ihx output file, and it should give no warnings
4443 such as not finding the string.h file.
4444 If it cannot find the string.h file, then the problem is that
4448 cannot find the /usr/local/share/sdcc/include directory
4455 \begin_inset LatexCommand \ref{sub:Install-Trouble-shooting}
4462 Install trouble-shooting section for suggestions).
4480 \begin_inset LatexCommand \index{-\/-print-search-dirs}
4484 to find exactly where SDCC is looking for the include and lib files.
4487 Install Trouble-shooting
4488 \begin_inset LatexCommand \label{sub:Install-Trouble-shooting}
4493 \begin_inset LatexCommand \index{Install trouble-shooting}
4500 If SDCC does not build correctly
4503 A thing to try is starting from scratch by unpacking the .tgz source package
4504 again in an empty directory.
4512 ./configure 2>&1 | tee configure.log
4526 make 2>&1 | tee make.log
4533 If anything goes wrong, you can review the log files to locate the problem.
4534 Or a relevant part of this can be attached to an email that could be helpful
4535 when requesting help from the mailing list.
4539 \begin_inset Quotes sld
4543 \begin_inset Quotes srd
4550 \begin_inset Quotes sld
4554 \begin_inset Quotes srd
4557 command is a script that analyzes your system and performs some configuration
4558 to ensure the source package compiles on your system.
4559 It will take a few minutes to run, and will compile a few tests to determine
4560 what compiler features are installed.
4564 \begin_inset Quotes sld
4568 \begin_inset Quotes srd
4574 This runs the GNU make tool, which automatically compiles all the source
4575 packages into the final installed binary executables.
4579 \begin_inset Quotes sld
4583 \begin_inset Quotes erd
4589 This will install the compiler, other executables libraries and include
4590 files into the appropriate directories.
4592 \begin_inset LatexCommand \ref{sub:Install-paths}
4598 \begin_inset LatexCommand \ref{sub:Search-Paths}
4603 about install and search paths.
4605 On most systems you will need super-user privileges to do this.
4611 SDCC is not just a compiler, but a collection of tools by various developers.
4612 These include linkers, assemblers, simulators and other components.
4613 Here is a summary of some of the components.
4614 Note that the included simulator and assembler have separate documentation
4615 which you can find in the source package in their respective directories.
4616 As SDCC grows to include support for other processors, other packages from
4617 various developers are included and may have their own sets of documentation.
4621 You might want to look at the files which are installed in <installdir>.
4622 At the time of this writing, we find the following programs for gcc-builds:
4626 In <installdir>/bin:
4629 sdcc - The compiler.
4632 sdcpp - The C preprocessor.
4635 asx8051 - The assembler for 8051 type processors.
4642 as-gbz80 - The Z80 and GameBoy Z80 assemblers.
4645 aslink -The linker for 8051 type processors.
4652 link-gbz80 - The Z80 and GameBoy Z80 linkers.
4655 s51 - The ucSim 8051 simulator.
4658 sdcdb - The source debugger.
4661 packihx - A tool to pack (compress) Intel hex files.
4664 In <installdir>/share/sdcc/include
4670 In <installdir>/share/sdcc/lib
4673 the subdirs src and small, large, z80, gbz80 and ds390 with the precompiled
4677 In <installdir>/share/sdcc/doc
4683 As development for other processors proceeds, this list will expand to include
4684 executables to support processors like AVR, PIC, etc.
4690 This is the actual compiler, it in turn uses the c-preprocessor and invokes
4691 the assembler and linkage editor.
4694 sdcpp - The C-Preprocessor
4698 \begin_inset LatexCommand \index{sdcpp (preprocessor)}
4702 is a modified version of the GNU cpp
4703 \begin_inset LatexCommand \index{cpp|see{sdcpp}}
4708 \begin_inset LatexCommand \url{http://gcc.gnu.org/}
4713 The C preprocessor is used to pull in #include sources, process #ifdef
4714 statements, #defines and so on.
4725 - The Assemblers and Linkage Editors
4728 This is retargettable assembler & linkage editor, it was developed by Alan
4730 John Hartman created the version for 8051, and I (Sandeep) have made some
4731 enhancements and bug fixes for it to work properly with SDCC.
4738 \begin_inset LatexCommand \index{s51}
4742 is a freeware, opensource simulator developed by Daniel Drotos.
4743 The simulator is built as part of the build process.
4744 For more information visit Daniel's web site at:
4745 \begin_inset LatexCommand \url{http://mazsola.iit.uni-miskolc.hu/~drdani/embedded/s51}
4750 It currently supports the core mcs51, the Dallas DS80C390 and the Phillips
4754 sdcdb - Source Level Debugger
4758 \begin_inset LatexCommand \index{SDCDB (debugger)}
4762 is the companion source level debugger.
4763 More about SDCDB in section
4764 \begin_inset LatexCommand \ref{cha:Debugging-with-SDCDB}
4769 The current version of the debugger uses Daniel's Simulator S51
4770 \begin_inset LatexCommand \index{s51}
4774 , but can be easily changed to use other simulators.
4783 Single Source File Projects
4786 For single source file 8051 projects the process is very simple.
4787 Compile your programs with the following command
4790 "sdcc sourcefile.c".
4794 This will compile, assemble and link your source file.
4795 Output files are as follows:
4799 \begin_inset LatexCommand \index{<file>.asm}
4804 \begin_inset LatexCommand \index{Assembler source}
4808 file created by the compiler
4812 \begin_inset LatexCommand \index{<file>.lst}
4817 \begin_inset LatexCommand \index{Assembler listing}
4821 file created by the Assembler
4825 \begin_inset LatexCommand \index{<file>.rst}
4830 \begin_inset LatexCommand \index{Assembler listing}
4834 file updated with linkedit information, created by linkage editor
4838 \begin_inset LatexCommand \index{<file>.sym}
4843 \begin_inset LatexCommand \index{Symbol listing}
4847 for the sourcefile, created by the assembler
4851 \begin_inset LatexCommand \index{<file>.rel}
4856 \begin_inset LatexCommand \index{<file>.o}
4861 \begin_inset LatexCommand \index{Object file}
4865 created by the assembler, input to Linkage editor
4869 \begin_inset LatexCommand \index{<file>.map}
4874 \begin_inset LatexCommand \index{Memory map}
4878 for the load module, created by the Linker
4882 \begin_inset LatexCommand \index{<file>.mem}
4886 - A file with a summary of the memory usage
4890 \begin_inset LatexCommand \index{<file>.ihx}
4894 - The load module in Intel hex format
4895 \begin_inset LatexCommand \index{Intel hex format}
4899 (you can select the Motorola S19 format
4900 \begin_inset LatexCommand \index{Motorola S19 format}
4915 \begin_inset LatexCommand \index{-\/-out-fmt-s19}
4920 If you need another format you might want to use
4927 \begin_inset LatexCommand \index{objdump (tool)}
4938 \begin_inset LatexCommand \index{srecord (bin, hex, ... tool)}
4943 Both formats are documented in the documentation of srecord
4944 \begin_inset LatexCommand \index{srecord (bin, hex, ... tool)}
4952 \begin_inset LatexCommand \index{<file>.adb}
4956 - An intermediate file containing debug information needed to create the
4968 \begin_inset LatexCommand \index{-\/-debug}
4976 \begin_inset LatexCommand \index{<file>.cdb}
4980 - An optional file (with -
4990 -debug) containing debug information.
4991 The format is documented in cdbfileformat.pdf
4996 \begin_inset LatexCommand \index{<file> (no extension)}
5000 An optional AOMF or AOMF51
5001 \begin_inset LatexCommand \index{AOMF, AOMF51}
5006 \begin_inset LatexCommand \label{OMF file}
5010 file containing debug information (generated with option -
5037 ormat is commonly used by third party tools (debuggers
5038 \begin_inset LatexCommand \index{Debugger}
5042 , simulators, emulators)
5046 \begin_inset LatexCommand \index{<file>.dump*}
5050 - Dump file to debug the compiler it self (generated with option -
5060 -dumpall) (see section
5061 \begin_inset LatexCommand \ref{sub:Intermediate-Dump-Options}
5067 \begin_inset LatexCommand \ref{sub:The-anatomy-of}
5073 \begin_inset Quotes sld
5076 Anatomy of the compiler
5077 \begin_inset Quotes srd
5083 Postprocessing the Intel Hex
5084 \begin_inset LatexCommand \index{Intel hex format}
5091 In most cases this won't be needed but the Intel Hex file
5092 \begin_inset LatexCommand \index{<file>.ihx}
5096 which is generated by SDCC might include lines of varying length and the
5097 addresses within the file are not guaranteed to be strictly ascending.
5098 If your toolchain or a bootloader does not like this you can use the tool
5104 \begin_inset LatexCommand \index{packihx (tool)}
5108 which is part of the SDCC distribution:
5115 packihx sourcefile.ihx >sourcefile.hex
5122 The separately available
5127 \begin_inset LatexCommand \index{srecord (bin, hex, ... tool)}
5131 package additionally allows to set undefined locations to a predefined
5132 value, to insert checksums
5133 \begin_inset LatexCommand \index{checksum}
5137 of various flavours (crc, add, xor) and to perform other manipulations
5138 (convert, split, crop, offset, ...).
5146 srec_cat\SpecialChar ~
5148 sourcefile.ihx -intel\SpecialChar ~
5150 -o sourcefile.hex -intel
5157 An example for a more complex command line
5163 the command backfills
5164 \begin_inset LatexCommand \index{backfill unused memory}
5168 unused memory with 0x12 and the overall 16 bit sum of the complete 64 kByte
5170 If the program counter on an mcs51 runs wild the backfill pattern 0x12
5171 will be interpreted as an
5179 (where an emergency routine could sit).
5190 srec_cat\SpecialChar ~
5191 sourcefile.ihx -intel\SpecialChar ~
5193 -fill 0x12 0x0000 0xfffe\SpecialChar ~
5194 -little-endian-checksum-nega
5195 tive 0xfffe 0x02 0x02\SpecialChar ~
5197 -o sourcefile.hex -intel
5206 The srecord package is available at
5207 \begin_inset LatexCommand \url{http://sf.net/projects/srecord}
5214 Projects with Multiple Source Files
5217 SDCC can compile only ONE file at a time.
5218 Let us for example assume that you have a project containing the following
5223 foo1.c (contains some functions)
5225 foo2.c (contains some more functions)
5227 foomain.c (contains more functions and the function main)
5235 The first two files will need to be compiled separately with the commands:
5267 Then compile the source file containing the
5272 \begin_inset LatexCommand \index{Linker}
5276 the files together with the following command:
5284 foomain.c\SpecialChar ~
5285 foo1.rel\SpecialChar ~
5290 \begin_inset LatexCommand \index{<file>.rel}
5302 can be separately compiled as well:
5313 sdcc foomain.rel foo1.rel foo2.rel
5320 The file containing the
5335 file specified in the command line, since the linkage editor processes
5336 file in the order they are presented to it.
5337 The linker is invoked from SDCC using a script file with extension .lnk
5338 \begin_inset LatexCommand \index{<file>.lnk}
5343 You can view this file to troubleshoot linking problems such as those arising
5344 from missing libraries.
5347 Projects with Additional Libraries
5348 \begin_inset LatexCommand \index{Libraries}
5355 Some reusable routines may be compiled into a library, see the documentation
5356 for the assembler and linkage editor (which are in <installdir>/share/sdcc/doc)
5360 \begin_inset LatexCommand \index{<file>.lib}
5367 Libraries created in this manner can be included in the command line.
5368 Make sure you include the -L <library-path> option to tell the linker where
5369 to look for these files if they are not in the current directory.
5370 Here is an example, assuming you have the source file
5382 (if that is not the same as your current project):
5389 sdcc foomain.c foolib.lib -L mylib
5400 must be an absolute path name.
5404 The most efficient way to use libraries is to keep separate modules in separate
5406 The lib file now should name all the modules.rel
5407 \begin_inset LatexCommand \index{<file>.rel}
5412 For an example see the standard library file
5416 in the directory <installdir>/share/lib/small.
5419 Using sdcclib to Create and Manage Libraries
5420 \begin_inset LatexCommand \index{sdcclib}
5427 Alternatively, instead of having a .rel file for each entry on the library
5428 file as described in the preceding section, sdcclib can be used to embed
5429 all the modules belonging to such library in the library file itself.
5430 This results in a larger library file, but it greatly reduces the number
5431 of disk files accessed by the linker.
5432 Additionally, the packed library file contains an index of all include
5433 modules and symbols that significantly speeds up the linking process.
5434 To display a list of options supported by sdcclib type:
5443 \begin_inset LatexCommand \index{sdcclib}
5454 To create a new library file, start by compiling all the required modules.
5492 This will create files _divsint.rel, _divuint.rel, _modsint.rel, _moduint.rel,
5494 The next step is to add the .rel files to the library file:
5502 sdcclib libint.lib _divsint.rel
5505 \begin_inset LatexCommand \index{sdcclib}
5515 sdcclib libint.lib _divuint.rel
5521 sdcclib libint.lib _modsint.rel
5527 sdcclib libint.lib _moduint.rel
5533 sdcclib libint.lib _mulint.rel
5540 If the file already exists in the library, it will be replaced.
5541 To see what modules and symbols are included in the library, options -s
5542 and -m are available.
5550 sdcclib -s libint.lib
5553 \begin_inset LatexCommand \index{sdcclib}
5662 \added_space_bottom bigskip
5663 If the source files are compiled using -
5674 \begin_inset LatexCommand \index{-\/-debug}
5678 , the corresponding debug information file .adb will be include in the library
5680 The library files created with sdcclib are plain text files, so they can
5681 be viewed with a text editor.
5682 It is not recomended to modify a library file created with sdcclib using
5683 a text editor, as there are file indexes numbers located accross the file
5684 used by the linker to quickly locate the required module to link.
5685 Once a .rel file (as well as a .adb file) is added to a library using sdcclib,
5686 it can be safely deleted, since all the information required for linking
5687 is embedded in the library file itself.
5688 Library files created using sdcclib are used as described in the preceding
5692 Command Line Options
5693 \begin_inset LatexCommand \index{Command Line Options}
5700 Processor Selection Options
5701 \begin_inset LatexCommand \index{Options processor selection}
5706 \begin_inset LatexCommand \index{Processor selection options}
5712 \labelwidthstring 00.00.0000
5717 \begin_inset LatexCommand \index{-mmcs51}
5723 Generate code for the Intel MCS51
5724 \begin_inset LatexCommand \index{MCS51}
5728 family of processors.
5729 This is the default processor target.
5731 \labelwidthstring 00.00.0000
5736 \begin_inset LatexCommand \index{-mds390}
5742 Generate code for the Dallas DS80C390
5743 \begin_inset LatexCommand \index{DS80C390}
5749 \labelwidthstring 00.00.0000
5754 \begin_inset LatexCommand \index{-mds400}
5760 Generate code for the Dallas DS80C400
5761 \begin_inset LatexCommand \index{DS80C400}
5767 \labelwidthstring 00.00.0000
5772 \begin_inset LatexCommand \index{-mhc08}
5778 Generate code for the Freescale/Motorola HC08
5779 \begin_inset LatexCommand \index{HC08}
5783 family of processors.
5785 \labelwidthstring 00.00.0000
5790 \begin_inset LatexCommand \index{-mz80}
5796 Generate code for the Zilog Z80
5797 \begin_inset LatexCommand \index{Z80}
5801 family of processors.
5803 \labelwidthstring 00.00.0000
5808 \begin_inset LatexCommand \index{-mgbz80}
5814 Generate code for the GameBoy Z80
5815 \begin_inset LatexCommand \index{gbz80 (GameBoy Z80)}
5819 processor (Not actively maintained).
5821 \labelwidthstring 00.00.0000
5826 \begin_inset LatexCommand \index{-mavr}
5832 Generate code for the Atmel AVR
5833 \begin_inset LatexCommand \index{AVR}
5837 processor (Not maintained, not complete).
5838 AVR users should probably have a look at winavr
5839 \begin_inset LatexCommand \url{http://sourceforge.net/projects/winavr}
5844 \begin_inset LatexCommand \url{http://www.avrfreaks.net/index.php?name=PNphpBB2&file=index}
5851 I think it is fair to direct users there for now.
5852 Open source is also about avoiding unnecessary work .
5853 But I didn't find the 'official' link.
5855 \labelwidthstring 00.00.0000
5860 \begin_inset LatexCommand \index{-mpic14}
5866 Generate code for the Microchip PIC 14
5867 \begin_inset LatexCommand \index{PIC14}
5871 -bit processors (p16f84 and variants.
5872 In development, not complete).
5875 p16f627 p16f628 p16f84 p16f873 p16f877?
5877 \labelwidthstring 00.00.0000
5882 \begin_inset LatexCommand \index{-mpic16}
5888 Generate code for the Microchip PIC 16
5889 \begin_inset LatexCommand \index{PIC16}
5893 -bit processors (p18f452 and variants.
5894 In development, not complete).
5896 \labelwidthstring 00.00.0000
5902 Generate code for the Toshiba TLCS-900H
5903 \begin_inset LatexCommand \index{TLCS-900H}
5907 processor (Not maintained, not complete).
5909 \added_space_bottom bigskip \labelwidthstring 00.00.0000
5914 \begin_inset LatexCommand \index{-mxa51}
5920 Generate code for the Phillips XA51
5921 \begin_inset LatexCommand \index{XA51}
5925 processor (Not maintained, not complete).
5928 Preprocessor Options
5929 \begin_inset LatexCommand \index{Options preprocessor}
5934 \begin_inset LatexCommand \index{Preprocessor options}
5939 \begin_inset LatexCommand \index{sdcpp (preprocessor)}
5945 \labelwidthstring 00.00.0000
5950 \begin_inset LatexCommand \index{-I<path>}
5956 The additional location where the pre processor will look for <..h> or
5957 \begin_inset Quotes eld
5961 \begin_inset Quotes erd
5966 \labelwidthstring 00.00.0000
5971 \begin_inset LatexCommand \index{-D<macro[=value]>}
5977 Command line definition of macros.
5978 Passed to the preprocessor.
5980 \labelwidthstring 00.00.0000
5985 \begin_inset LatexCommand \index{-M}
5991 Tell the preprocessor to output a rule suitable for make describing the
5992 dependencies of each object file.
5993 For each source file, the preprocessor outputs one make-rule whose target
5994 is the object file name for that source file and whose dependencies are
5995 all the files `#include'd in it.
5996 This rule may be a single line or may be continued with `
5998 '-newline if it is long.
5999 The list of rules is printed on standard output instead of the preprocessed
6002 \begin_inset LatexCommand \index{-E}
6008 \labelwidthstring 00.00.0000
6013 \begin_inset LatexCommand \index{-C}
6019 Tell the preprocessor not to discard comments.
6020 Used with the `-E' option.
6022 \labelwidthstring 00.00.0000
6027 \begin_inset LatexCommand \index{-MM}
6038 Like `-M' but the output mentions only the user header files included with
6040 \begin_inset Quotes eld
6044 System header files included with `#include <file>' are omitted.
6046 \labelwidthstring 00.00.0000
6051 \begin_inset LatexCommand \index{-Aquestion(answer)}
6057 Assert the answer answer for question, in case it is tested with a preprocessor
6058 conditional such as `#if #question(answer)'.
6059 `-A-' disables the standard assertions that normally describe the target
6062 \labelwidthstring 00.00.0000
6067 \begin_inset LatexCommand \index{-Umacro}
6073 Undefine macro macro.
6074 `-U' options are evaluated after all `-D' options, but before any `-include'
6075 and `-imacros' options.
6077 \labelwidthstring 00.00.0000
6082 \begin_inset LatexCommand \index{-dM}
6088 Tell the preprocessor to output only a list of the macro definitions that
6089 are in effect at the end of preprocessing.
6090 Used with the `-E' option.
6092 \labelwidthstring 00.00.0000
6097 \begin_inset LatexCommand \index{-dD}
6103 Tell the preprocessor to pass all macro definitions into the output, in
6104 their proper sequence in the rest of the output.
6106 \labelwidthstring 00.00.0000
6111 \begin_inset LatexCommand \index{-dN}
6122 Like `-dD' except that the macro arguments and contents are omitted.
6123 Only `#define name' is included in the output.
6125 \labelwidthstring 00.00.0000
6129 -pedantic-parse-number
6130 \begin_inset LatexCommand \index{-pedantic-parse-number}
6141 Pedentic parse numbers so that situations like 0xfe-LO_B(3) are parsed properly
6142 and the macro LO_B(3) gets expanded.
6143 See also #pragma pedantic_parse_number in section
6144 \begin_inset LatexCommand \ref{sec:Pragmas}
6150 Note: this functionality is not in conformance with standard!
6152 \added_space_bottom bigskip \labelwidthstring 00.00.0000
6157 preprocessorOption[,preprocessorOption]
6160 \begin_inset LatexCommand \index{-Wp preprocessorOption[,preprocessorOption]}
6165 Pass the preprocessorOption to the preprocessor
6170 \begin_inset LatexCommand \index{sdcpp (preprocessor)}
6175 SDCC uses an adapted version of the preprocessor
6179 of the GNU Compiler Collection
6180 \begin_inset LatexCommand \index{gcc (GNU Compiler Collection)}
6189 \begin_inset LatexCommand \url{http://gcc.gnu.org/}
6193 ), if you need more dedicated options please refer to the GCC\SpecialChar ~
6198 \begin_inset LatexCommand \htmlurl{http://www.gnu.org/software/gcc/onlinedocs/}
6206 \begin_inset LatexCommand \index{Options linker}
6211 \begin_inset LatexCommand \index{Linker options}
6217 \labelwidthstring 00.00.0000
6237 \begin_inset LatexCommand \index{-\/-lib-path <path>}
6242 \begin_inset LatexCommand \index{-L -\/-lib-path}
6249 <absolute path to additional libraries> This option is passed to the linkage
6250 editor's additional libraries
6251 \begin_inset LatexCommand \index{Libraries}
6256 The path name must be absolute.
6257 Additional library files may be specified in the command line.
6258 See section Compiling programs for more details.
6260 \labelwidthstring 00.00.0000
6277 \begin_inset LatexCommand \index{-\/-xram-loc <Value>}
6282 <Value> The start location of the external ram
6283 \begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
6287 , default value is 0.
6288 The value entered can be in Hexadecimal or Decimal format, e.g.: -
6298 -xram-loc 0x8000 or -
6310 \labelwidthstring 00.00.0000
6327 \begin_inset LatexCommand \index{-\/-code-loc <Value>}
6332 <Value> The start location of the code
6333 \begin_inset LatexCommand \index{code}
6337 segment, default value 0.
6338 Note when this option is used the interrupt vector table
6339 \begin_inset LatexCommand \index{interrupt vector table}
6343 is also relocated to the given address.
6344 The value entered can be in Hexadecimal or Decimal format, e.g.: -
6354 -code-loc 0x8000 or -
6366 \labelwidthstring 00.00.0000
6383 \begin_inset LatexCommand \index{-\/-stack-loc <Value>}
6388 <Value> By default the stack
6389 \begin_inset LatexCommand \index{stack}
6393 is placed after the data segment.
6394 Using this option the stack can be placed anywhere in the internal memory
6396 The value entered can be in Hexadecimal or Decimal format, e.g.
6407 -stack-loc 0x20 or -
6418 Since the sp register is incremented before a push or call, the initial
6419 sp will be set to one byte prior the provided value.
6420 The provided value should not overlap any other memory areas such as used
6421 register banks or the data segment and with enough space for the current
6439 \begin_inset LatexCommand \index{-\/-pack-iram}
6443 option (which is now a default setting) will override this setting, so
6444 you should also specify the
6460 \begin_inset LatexCommand \index{-\/-no-pack-iram}
6464 option if you need to manually place the stack.
6466 \labelwidthstring 00.00.0000
6483 \begin_inset LatexCommand \index{-\/-xstack-loc <Value>}
6488 <Value> By default the external stack
6489 \begin_inset LatexCommand \index{xstack}
6493 is placed after the pdata
6494 \begin_inset LatexCommand \index{pdata (mcs51, ds390 storage class)}
6499 Using this option the xstack can be placed anywhere in the external memory
6501 The value entered can be in Hexadecimal or Decimal format, e.g.
6512 -xstack-loc 0x8000 or -
6523 The provided value should not overlap any other memory areas such as the
6524 pdata or xdata segment and with enough space for the current application.
6526 \labelwidthstring 00.00.0000
6543 \begin_inset LatexCommand \index{-\/-data-loc <Value>}
6548 <Value> The start location of the internal ram data
6549 \begin_inset LatexCommand \index{data (mcs51, ds390 storage class)}
6554 The value entered can be in Hexadecimal or Decimal format, eg.
6576 (By default, the start location of the internal ram data segment is set
6577 as low as possible in memory, taking into account the used register banks
6578 and the bit segment at address 0x20.
6579 For example if register banks 0 and 1 are used without bit variables, the
6580 data segment will be set, if -
6590 -data-loc is not used, to location 0x10.)
6592 \labelwidthstring 00.00.0000
6609 \begin_inset LatexCommand \index{-\/-idata-loc <Value>}
6614 <Value> The start location of the indirectly addressable internal ram
6615 \begin_inset LatexCommand \index{idata (mcs51, ds390 storage class)}
6619 of the 8051, default value is 0x80.
6620 The value entered can be in Hexadecimal or Decimal format, eg.
6631 -idata-loc 0x88 or -
6643 \labelwidthstring 00.00.0000
6660 <Value> The start location of the bit
6661 \begin_inset LatexCommand \index{bit}
6665 addressable internal ram of the 8051.
6671 Instead an option can be passed directly to the linker: -Wl\SpecialChar ~
6674 \labelwidthstring 00.00.0000
6689 \begin_inset LatexCommand \index{-\/-out-fmt-ihx}
6698 The linker output (final object code) is in Intel Hex format.
6699 \begin_inset LatexCommand \index{Intel hex format}
6703 This is the default option.
6704 The format itself is documented in the documentation of srecord
6705 \begin_inset LatexCommand \index{srecord (bin, hex, ... tool)}
6711 \labelwidthstring 00.00.0000
6726 \begin_inset LatexCommand \index{-\/-out-fmt-s19}
6735 The linker output (final object code) is in Motorola S19 format
6736 \begin_inset LatexCommand \index{Motorola S19 format}
6741 The format itself is documented in the documentation of srecord.
6743 \labelwidthstring 00.00.0000
6758 \begin_inset LatexCommand \index{-\/-out-fmt-s19}
6763 \begin_inset LatexCommand \index{HC08!Options!-\/-out-fmt-elf}
6772 The linker output (final object code) is in ELF format
6773 \begin_inset LatexCommand \index{ELF format}
6778 (Currently only supported for the HC08
6779 \begin_inset LatexCommand \index{HC08}
6785 \added_space_bottom bigskip \labelwidthstring 00.00.0000
6790 linkOption[,linkOption]
6793 \begin_inset LatexCommand \index{-Wl linkOption[,linkOption]}
6798 Pass the linkOption to the linker.
6799 If a bootloader is used an option like
6800 \begin_inset Quotes sld
6805 \begin_inset Quotes srd
6808 would be typical to set the start of the code segment.
6809 See also #pragma constseg and #pragma codeseg in section
6810 \begin_inset LatexCommand \ref{sec:Pragmas}
6815 File sdcc/as/doc/asxhtm.html has more on linker options.
6819 \begin_inset LatexCommand \index{Options MCS51}
6824 \begin_inset LatexCommand \index{MCS51 options}
6830 \labelwidthstring 00.00.0000
6845 \begin_inset LatexCommand \index{-\/-model-small}
6856 Generate code for Small Model programs, see section Memory Models for more
6858 This is the default model.
6860 \labelwidthstring 00.00.0000
6875 \begin_inset LatexCommand \index{-\/-model-medium}
6881 Generate code for Medium model programs, see section Memory Models for
6883 If this option is used all source files in the project have to be compiled
6885 It must also be used when invoking the linker.
6887 \labelwidthstring 00.00.0000
6902 \begin_inset LatexCommand \index{-\/-model-large}
6908 Generate code for Large model programs, see section Memory Models for more
6910 If this option is used all source files in the project have to be compiled
6912 It must also be used when invoking the linker.
6914 \labelwidthstring 00.00.0000
6929 \begin_inset LatexCommand \index{-\/-xstack}
6935 Uses a pseudo stack in the pdata
6936 \begin_inset LatexCommand \index{pdata (mcs51, ds390 storage class)}
6940 area (usually the first 256 bytes in the external ram) for allocating variables
6941 and passing parameters.
6943 \begin_inset LatexCommand \ref{sub:External-Stack}
6948 External Stack for more details.
6950 \labelwidthstring 00.00.0000
6968 \begin_inset LatexCommand \index{-\/-iram-size <Value>}
6972 Causes the linker to check if the internal ram usage is within limits of
6975 \labelwidthstring 00.00.0000
6993 \begin_inset LatexCommand \index{-\/-xram-size <Value>}
6997 Causes the linker to check if the external ram usage is within limits of
7000 \labelwidthstring 00.00.0000
7018 \begin_inset LatexCommand \index{-\/-code-size <Value>}
7022 Causes the linker to check if the code memory usage is within limits of
7025 \labelwidthstring 00.00.0000
7043 \begin_inset LatexCommand \index{-\/-stack-size <Value>}
7047 Causes the linker to check if there is at minimum <Value> bytes for stack.
7049 \labelwidthstring 00.00.0000
7067 \begin_inset LatexCommand \index{-\/-pack-iram}
7071 Causes the linker to use unused register banks for data variables and pack
7072 data, idata and stack together.
7073 This is the default now.
7075 \added_space_bottom bigskip \labelwidthstring 00.00.0000
7093 \begin_inset LatexCommand \index{-\/-no-pack-iram}
7097 Causes the linker to use old style for allocating memory areas.
7100 DS390 / DS400 Options
7101 \begin_inset LatexCommand \index{Options DS390}
7106 \begin_inset LatexCommand \index{DS390}
7112 \labelwidthstring 00.00.0000
7129 \begin_inset LatexCommand \index{DS390!Options!-\/-model-flat24}
7139 Generate 24-bit flat mode code.
7140 This is the one and only that the ds390 code generator supports right now
7141 and is default when using
7146 See section Memory Models for more details.
7148 \labelwidthstring 00.00.0000
7163 \begin_inset LatexCommand \index{DS390!Options!-\/-protect-sp-update}
7169 disable interrupts during ESP:SP updates.
7171 \labelwidthstring 00.00.0000
7188 \begin_inset LatexCommand \index{DS390!Options!-\/-stack-10bit}
7192 Generate code for the 10 bit stack mode of the Dallas DS80C390 part.
7193 This is the one and only that the ds390 code generator supports right now
7194 and is default when using
7199 In this mode, the stack is located in the lower 1K of the internal RAM,
7200 which is mapped to 0x400000.
7201 Note that the support is incomplete, since it still uses a single byte
7202 as the stack pointer.
7203 This means that only the lower 256 bytes of the potential 1K stack space
7204 will actually be used.
7205 However, this does allow you to reclaim the precious 256 bytes of low RAM
7206 for use for the DATA and IDATA segments.
7207 The compiler will not generate any code to put the processor into 10 bit
7209 It is important to ensure that the processor is in this mode before calling
7210 any re-entrant functions compiled with this option.
7211 In principle, this should work with the
7224 \begin_inset LatexCommand \index{-\/-stack-auto}
7230 option, but that has not been tested.
7231 It is incompatible with the
7244 \begin_inset LatexCommand \index{-\/-xstack}
7251 It also only makes sense if the processor is in 24 bit contiguous addressing
7264 -model-flat24 option
7268 \labelwidthstring 00.00.0000
7283 \begin_inset LatexCommand \index{DS390!Options!-\/-stack-probe}
7289 insert call to function __stack_probe at each function prologue.
7291 \labelwidthstring 00.00.0000
7306 \begin_inset LatexCommand \index{DS390!Options!-\/-tini-libid}
7312 <nnnn> LibraryID used in -mTININative.
7315 \added_space_bottom bigskip \labelwidthstring 00.00.0000
7330 \begin_inset LatexCommand \index{DS390!Options!-\/-use-accelerator}
7336 generate code for DS390 Arithmetic Accelerator.
7341 \begin_inset LatexCommand \index{Options Z80}
7346 \begin_inset LatexCommand \index{Z80}
7352 \labelwidthstring 00.00.0000
7369 \begin_inset LatexCommand \index{Z80!Options!-\/-callee-saves-bc}
7379 Force a called function to always save BC.
7381 \added_space_bottom bigskip \labelwidthstring 00.00.0000
7398 \begin_inset LatexCommand \index{Z80!Options!-\/-no-std-crt0}
7402 When linking, skip the standard crt0.o object file.
7403 You must provide your own crt0.o for your system when linking.
7407 Optimization Options
7408 \begin_inset LatexCommand \index{Options optimization}
7413 \begin_inset LatexCommand \index{Optimization options}
7419 \labelwidthstring 00.00.0000
7434 \begin_inset LatexCommand \index{-\/-nogcse}
7440 Will not do global subexpression elimination, this option may be used when
7441 the compiler creates undesirably large stack/data spaces to store compiler
7451 \begin_inset LatexCommand \index{sloc (spill location)}
7456 A warning message will be generated when this happens and the compiler
7457 will indicate the number of extra bytes it allocated.
7458 It is recommended that this option NOT be used, #pragma\SpecialChar ~
7460 \begin_inset LatexCommand \index{\#pragma nogcse}
7464 can be used to turn off global subexpression elimination
7465 \begin_inset LatexCommand \index{Subexpression elimination}
7469 for a given function only.
7471 \labelwidthstring 00.00.0000
7486 \begin_inset LatexCommand \index{-\/-noinvariant}
7492 Will not do loop invariant optimizations, this may be turned off for reasons
7493 explained for the previous option.
7494 For more details of loop optimizations performed see Loop Invariants in
7496 \begin_inset LatexCommand \ref{sub:Loop-Optimizations}
7501 It is recommended that this option NOT be used, #pragma\SpecialChar ~
7503 \begin_inset LatexCommand \index{\#pragma noinvariant}
7507 can be used to turn off invariant optimizations for a given function only.
7509 \labelwidthstring 00.00.0000
7524 \begin_inset LatexCommand \index{-\/-noinduction}
7530 Will not do loop induction optimizations, see section strength reduction
7532 It is recommended that this option is NOT used, #pragma\SpecialChar ~
7534 \begin_inset LatexCommand \index{\#pragma noinduction}
7538 can be used to turn off induction optimizations for a given function only.
7540 \labelwidthstring 00.00.0000
7555 \begin_inset LatexCommand \index{-\/-nojtbound}
7566 Will not generate boundary condition check when switch statements
7567 \begin_inset LatexCommand \index{switch statement}
7571 are implemented using jump-tables.
7573 \begin_inset LatexCommand \ref{sub:'switch'-Statements}
7578 Switch Statements for more details.
7579 It is recommended that this option is NOT used, #pragma\SpecialChar ~
7581 \begin_inset LatexCommand \index{\#pragma nojtbound}
7585 can be used to turn off boundary checking for jump tables for a given function
7588 \labelwidthstring 00.00.0000
7603 \begin_inset LatexCommand \index{-\/-noloopreverse}
7612 Will not do loop reversal
7613 \begin_inset LatexCommand \index{Loop reversing}
7619 \labelwidthstring 00.00.0000
7636 \begin_inset LatexCommand \index{-\/-nolabelopt }
7640 Will not optimize labels (makes the dumpfiles more readable).
7642 \labelwidthstring 00.00.0000
7657 \begin_inset LatexCommand \index{-\/-no-xinit-opt}
7663 Will not memcpy initialized data from code space into xdata space.
7664 This saves a few bytes in code space if you don't have initialized data
7665 \begin_inset LatexCommand \index{Variable initialization}
7671 \labelwidthstring 00.00.0000
7686 \begin_inset LatexCommand \index{-\/-nooverlay}
7692 The compiler will not overlay parameters and local variables of any function,
7693 see section Parameters and local variables for more details.
7695 \labelwidthstring 00.00.0000
7710 \begin_inset LatexCommand \index{-\/-no-peep}
7716 Disable peep-hole optimization with built-in rules.
7718 \labelwidthstring 00.00.0000
7735 \begin_inset LatexCommand \index{-\/-peep-file}
7740 <filename> This option can be used to use additional rules to be used by
7741 the peep hole optimizer.
7743 \begin_inset LatexCommand \ref{sub:Peephole-Optimizer}
7748 Peep Hole optimizations for details on how to write these rules.
7750 \labelwidthstring 00.00.0000
7765 \begin_inset LatexCommand \index{-\/-peep-asm}
7771 Pass the inline assembler code through the peep hole optimizer.
7772 This can cause unexpected changes to inline assembler code, please go through
7773 the peephole optimizer
7774 \begin_inset LatexCommand \index{Peephole optimizer}
7778 rules defined in the source file tree '<target>/peeph.def' before using
7781 \labelwidthstring 00.00.0000
7796 \begin_inset LatexCommand \index{-\/-opt-code-speed}
7802 The compiler will optimize code generation towards fast code, possibly
7803 at the expense of code size.
7805 \added_space_bottom bigskip \labelwidthstring 00.00.0000
7820 \begin_inset LatexCommand \index{-\/-opt-code-size}
7826 The compiler will optimize code generation towards compact code, possibly
7827 at the expense of code speed.
7831 \begin_inset LatexCommand \index{Options other}
7837 \labelwidthstring 00.00.0000
7853 \begin_inset LatexCommand \index{-\/-compile-only}
7858 \begin_inset LatexCommand \index{-c -\/-compile-only}
7864 will compile and assemble the source, but will not call the linkage editor.
7866 \labelwidthstring 00.00.0000
7885 \begin_inset LatexCommand \index{-\/-c1mode}
7891 reads the preprocessed source from standard input and compiles it.
7892 The file name for the assembler output must be specified using the -o option.
7894 \labelwidthstring 00.00.0000
7899 \begin_inset LatexCommand \index{-E}
7905 Run only the C preprocessor.
7906 Preprocess all the C source files specified and output the results to standard
7909 \labelwidthstring 00.00.0000
7915 \begin_inset LatexCommand \index{-o <path/file>}
7921 The output path resp.
7922 file where everything will be placed.
7923 If the parameter is a path, it must have a trailing slash (or backslash
7924 for the Windows binaries) to be recognized as a path.
7927 \labelwidthstring 00.00.0000
7942 \begin_inset LatexCommand \index{-\/-stack-auto}
7953 All functions in the source file will be compiled as
7958 \begin_inset LatexCommand \index{reentrant}
7963 the parameters and local variables will be allocated on the stack
7964 \begin_inset LatexCommand \index{stack}
7970 \begin_inset LatexCommand \ref{sec:Parameters-and-Local-Variables}
7974 Parameters and Local Variables for more details.
7975 If this option is used all source files in the project should be compiled
7977 It automatically implies --int-long-reent and --float-reent.
7980 \labelwidthstring 00.00.0000
7995 \begin_inset LatexCommand \index{-\/-callee-saves}
7999 function1[,function2][,function3]....
8002 The compiler by default uses a caller saves convention for register saving
8003 across function calls, however this can cause unnecessary register pushing
8004 & popping when calling small functions from larger functions.
8005 This option can be used to switch the register saving convention for the
8006 function names specified.
8007 The compiler will not save registers when calling these functions, no extra
8008 code will be generated at the entry & exit (function prologue
8011 \begin_inset LatexCommand \index{function prologue}
8020 \begin_inset LatexCommand \index{function epilogue}
8026 ) for these functions to save & restore the registers used by these functions,
8027 this can SUBSTANTIALLY reduce code & improve run time performance of the
8029 In the future the compiler (with inter procedural analysis) will be able
8030 to determine the appropriate scheme to use for each function call.
8031 DO NOT use this option for built-in functions such as _mulint..., if this
8032 option is used for a library function the appropriate library function
8033 needs to be recompiled with the same option.
8034 If the project consists of multiple source files then all the source file
8035 should be compiled with the same -
8045 -callee-saves option string.
8046 Also see #pragma\SpecialChar ~
8048 \begin_inset LatexCommand \index{\#pragma callee\_saves}
8054 \labelwidthstring 00.00.0000
8069 \begin_inset LatexCommand \index{-\/-debug}
8078 When this option is used the compiler will generate debug information.
8079 The debug information collected in a file with .cdb extension can be used
8081 For more information see documentation for SDCDB.
8082 Another file with no extension contains debug information in AOMF or AOMF51
8083 \begin_inset LatexCommand \index{AOMF, AOMF51}
8087 format which is commonly used by third party tools.
8089 \labelwidthstring 00.00.0000
8094 \begin_inset LatexCommand \index{-S}
8105 Stop after the stage of compilation proper; do not assemble.
8106 The output is an assembler code file for the input file specified.
8108 \labelwidthstring 00.00.0000
8123 \begin_inset LatexCommand \index{-\/-int-long-reent}
8129 Integer (16 bit) and long (32 bit) libraries have been compiled as reentrant.
8130 Note by default these libraries are compiled as non-reentrant.
8131 See section Installation for more details.
8133 \labelwidthstring 00.00.0000
8148 \begin_inset LatexCommand \index{-\/-cyclomatic}
8157 This option will cause the compiler to generate an information message for
8158 each function in the source file.
8159 The message contains some
8163 information about the function.
8164 The number of edges and nodes the compiler detected in the control flow
8165 graph of the function, and most importantly the
8167 cyclomatic complexity
8168 \begin_inset LatexCommand \index{Cyclomatic complexity}
8174 see section on Cyclomatic Complexity for more details.
8176 \labelwidthstring 00.00.0000
8191 \begin_inset LatexCommand \index{-\/-float-reent}
8197 Floating point library is compiled as reentrant
8198 \begin_inset LatexCommand \index{reentrant}
8203 See section Installation for more details.
8205 \labelwidthstring 00.00.0000
8220 \begin_inset LatexCommand \index{-\/-main-return}
8226 This option can be used if the code generated is called by a monitor program
8227 or if the main routine includes an endless loop.
8228 This option results in slightly smaller code and saves two bytes of stack
8230 The return from the 'main'
8231 \begin_inset LatexCommand \index{main return}
8235 function will return to the function calling main.
8236 The default setting is to lock up i.e.
8243 \labelwidthstring 00.00.0000
8258 \begin_inset LatexCommand \index{-\/-nostdinc}
8264 This will prevent the compiler from passing on the default include path
8265 to the preprocessor.
8267 \labelwidthstring 00.00.0000
8282 \begin_inset LatexCommand \index{-\/-nostdlib}
8288 This will prevent the compiler from passing on the default library
8289 \begin_inset LatexCommand \index{Libraries}
8295 \labelwidthstring 00.00.0000
8310 \begin_inset LatexCommand \index{-\/-verbose}
8316 Shows the various actions the compiler is performing.
8318 \labelwidthstring 00.00.0000
8323 \begin_inset LatexCommand \index{-V}
8329 Shows the actual commands the compiler is executing.
8331 \labelwidthstring 00.00.0000
8346 \begin_inset LatexCommand \index{-\/-no-c-code-in-asm}
8352 Hides your ugly and inefficient c-code from the asm file, so you can always
8353 blame the compiler :)
8355 \labelwidthstring 00.00.0000
8370 \begin_inset LatexCommand \index{-\/-no-peep-comments}
8376 Will not include peep-hole comments in the generated files.
8378 \labelwidthstring 00.00.0000
8393 \begin_inset LatexCommand \index{-\/-i-code-in-asm}
8399 Include i-codes in the asm file.
8400 Sounds like noise but is most helpful for debugging the compiler itself.
8402 \labelwidthstring 00.00.0000
8417 \begin_inset LatexCommand \index{-\/-less-pedantic}
8423 Disable some of the more pedantic warnings
8424 \begin_inset LatexCommand \index{Warnings}
8428 (jwk burps: please be more specific here, please!).
8430 \labelwidthstring 00.00.0000
8444 -disable-warning\SpecialChar ~
8446 \begin_inset LatexCommand \index{-\/-disable-warning}
8452 Disable specific warning with number <nnnn>.
8454 \labelwidthstring 00.00.0000
8469 \begin_inset LatexCommand \index{-\/-print-search-dirs}
8475 Display the directories in the compiler's search path
8477 \labelwidthstring 00.00.0000
8492 \begin_inset LatexCommand \index{-\/-vc}
8498 Display errors and warnings using MSVC style, so you can use SDCC with
8499 the visual studio IDE
8500 \begin_inset LatexCommand \index{IDE}
8505 With SDCC both offering a GCC-like (the default) and a MSVC-like
8506 \begin_inset LatexCommand \index{MSVC output style}
8510 output style, integration into most programming editors should be straightforwa
8513 \labelwidthstring 00.00.0000
8528 \begin_inset LatexCommand \index{-\/-use-stdout}
8534 Send errors and warnings to stdout instead of stderr.
8536 \labelwidthstring 00.00.0000
8541 asmOption[,asmOption]
8544 \begin_inset LatexCommand \index{-Wa asmOption[,asmOption]}
8549 Pass the asmOption to the assembler
8550 \begin_inset LatexCommand \index{Options assembler}
8555 \begin_inset LatexCommand \index{Assembler options}
8560 See file sdcc/as/doc/asxhtm.html for assembler options.cd
8562 \labelwidthstring 00.00.0000
8577 \begin_inset LatexCommand \index{-\/-std-sdcc89}
8583 Generally follow the C89 standard, but allow SDCC features that conflict
8584 with the standard (default).
8586 \labelwidthstring 00.00.0000
8601 \begin_inset LatexCommand \index{-\/-std-c89}
8607 Follow the C89 standard and disable SDCC features that conflict with the
8610 \labelwidthstring 00.00.0000
8625 \begin_inset LatexCommand \index{-\/-std-sdcc99}
8631 Generally follow the C99 standard, but allow SDCC features that conflict
8632 with the standard (incomplete support).
8634 \labelwidthstring 00.00.0000
8649 \begin_inset LatexCommand \index{-\/-std-sdcc99}
8655 Follow the C99 standard and disable SDCC features that conflict with the
8656 standard (incomplete support).
8658 \labelwidthstring 00.00.0000
8675 \begin_inset LatexCommand \index{-\/-codeseg <Value>}
8680 <Name> The name to be used for the code
8681 \begin_inset LatexCommand \index{code}
8685 segment, default CSEG.
8686 This is useful if you need to tell the compiler to put the code in a special
8687 segment so you can later on tell the linker to put this segment in a special
8689 Can be used for instance when using bank switching to put the code in a
8692 \labelwidthstring 00.00.0000
8709 \begin_inset LatexCommand \index{-\/-constseg <Value>}
8714 <Name> The name to be used for the const
8715 \begin_inset LatexCommand \index{code}
8719 segment, default CONST.
8720 This is useful if you need to tell the compiler to put the const data in
8721 a special segment so you can later on tell the linker to put this segment
8722 in a special place in memory.
8723 Can be used for instance when using bank switching to put the const data
8726 \added_space_bottom bigskip \labelwidthstring 00.00.0000
8738 a SDCC compiler option but if you want
8742 warnings you can use a separate tool dedicated to syntax checking like
8744 \begin_inset LatexCommand \label{lyx:more-pedantic-SPLINT}
8749 \begin_inset LatexCommand \index{lint (syntax checking tool)}
8754 \begin_inset LatexCommand \url{http://www.splint.org}
8759 To make your source files parseable by splint you will have to include
8765 \begin_inset LatexCommand \index{splint (syntax checking tool)}
8769 in your source file and add brackets around extended keywords (like
8772 \begin_inset Quotes sld
8785 \begin_inset Quotes srd
8793 \begin_inset Quotes sld
8796 __interrupt\SpecialChar ~
8798 \begin_inset Quotes srd
8806 Splint has an excellent on line manual at
8807 \begin_inset LatexCommand \url{http://www.splint.org/manual/}
8811 and it's capabilities go beyond pure syntax checking.
8812 You'll need to tell splint the location of SDCC's include files so a typical
8813 command line could look like this:
8817 splint\SpecialChar ~
8819 /usr/local/share/sdcc/include/mcs51/\SpecialChar ~
8824 Intermediate Dump Options
8825 \begin_inset LatexCommand \label{sub:Intermediate-Dump-Options}
8830 \begin_inset LatexCommand \index{Options intermediate dump}
8835 \begin_inset LatexCommand \index{Intermediate dump options}
8842 The following options are provided for the purpose of retargetting and debugging
8844 They provide a means to dump the intermediate code (iCode
8845 \begin_inset LatexCommand \index{iCode}
8849 ) generated by the compiler in human readable form at various stages of
8850 the compilation process.
8851 More on iCodes see chapter
8852 \begin_inset LatexCommand \ref{sub:The-anatomy-of}
8857 \begin_inset Quotes srd
8860 The anatomy of the compiler
8861 \begin_inset Quotes srd
8866 \labelwidthstring 00.00.0000
8881 \begin_inset LatexCommand \index{-\/-dumpraw}
8887 This option will cause the compiler to dump the intermediate code into
8890 <source filename>.dumpraw
8892 just after the intermediate code has been generated for a function, i.e.
8893 before any optimizations are done.
8895 \begin_inset LatexCommand \index{Basic blocks}
8899 at this stage ordered in the depth first number, so they may not be in
8900 sequence of execution.
8902 \labelwidthstring 00.00.0000
8917 \begin_inset LatexCommand \index{-\/-dumpgcse}
8923 Will create a dump of iCode's, after global subexpression elimination
8924 \begin_inset LatexCommand \index{Global subexpression elimination}
8930 <source filename>.dumpgcse.
8932 \labelwidthstring 00.00.0000
8947 \begin_inset LatexCommand \index{-\/-dumpdeadcode}
8953 Will create a dump of iCode's, after deadcode elimination
8954 \begin_inset LatexCommand \index{Dead-code elimination}
8960 <source filename>.dumpdeadcode.
8962 \labelwidthstring 00.00.0000
8977 \begin_inset LatexCommand \index{-\/-dumploop}
8986 Will create a dump of iCode's, after loop optimizations
8987 \begin_inset LatexCommand \index{Loop optimization}
8993 <source filename>.dumploop.
8995 \labelwidthstring 00.00.0000
9010 \begin_inset LatexCommand \index{-\/-dumprange}
9019 Will create a dump of iCode's, after live range analysis
9020 \begin_inset LatexCommand \index{Live range analysis}
9026 <source filename>.dumprange.
9028 \labelwidthstring 00.00.0000
9043 \begin_inset LatexCommand \index{-\/-dumlrange}
9049 Will dump the life ranges
9050 \begin_inset LatexCommand \index{Live range analysis}
9056 \labelwidthstring 00.00.0000
9071 \begin_inset LatexCommand \index{-\/-dumpregassign}
9080 Will create a dump of iCode's, after register assignment
9081 \begin_inset LatexCommand \index{Register assignment}
9087 <source filename>.dumprassgn.
9089 \labelwidthstring 00.00.0000
9104 \begin_inset LatexCommand \index{-\/-dumplrange}
9110 Will create a dump of the live ranges of iTemp's
9112 \added_space_bottom bigskip \labelwidthstring 00.00.0000
9127 \begin_inset LatexCommand \index{-\/-dumpall}
9138 Will cause all the above mentioned dumps to be created.
9141 Redirecting output on Windows Shells
9143 \added_space_bottom bigskip
9144 By default SDCC writes it's error messages to
9145 \begin_inset Quotes sld
9149 \begin_inset Quotes srd
9153 To force all messages to
9154 \begin_inset Quotes sld
9158 \begin_inset Quotes srd
9182 \begin_inset LatexCommand \index{-\/-use-stdout}
9187 Additionally, if you happen to have visual studio installed in your windows
9188 machine, you can use it to compile your sources using a custom build and
9204 \begin_inset LatexCommand \index{-\/-vc}
9209 Something like this should work:
9253 -model-large -c $(InputPath)
9256 Environment variables
9257 \begin_inset LatexCommand \index{Environment variables}
9264 SDCC recognizes the following environment variables:
9266 \labelwidthstring 00.00.0000
9271 \begin_inset LatexCommand \index{SDCC\_LEAVE\_SIGNALS}
9277 SDCC installs a signal handler
9278 \begin_inset LatexCommand \index{signal handler}
9282 to be able to delete temporary files after an user break (^C) or an exception.
9283 If this environment variable is set, SDCC won't install the signal handler
9284 in order to be able to debug SDCC.
9286 \labelwidthstring 00.00.0000
9293 \begin_inset LatexCommand \index{TMP, TEMP, TMPDIR}
9299 Path, where temporary files will be created.
9300 The order of the variables is the search order.
9301 In a standard *nix environment these variables are not set, and there's
9302 no need to set them.
9303 On Windows it's recommended to set one of them.
9305 \labelwidthstring 00.00.0000
9310 \begin_inset LatexCommand \index{SDCC\_HOME}
9317 \begin_inset LatexCommand \ref{sub:Install-paths}
9323 \begin_inset Quotes sld
9327 \begin_inset Quotes srd
9332 \labelwidthstring 00.00.0000
9337 \begin_inset LatexCommand \index{SDCC\_INCLUDE}
9344 \begin_inset LatexCommand \ref{sub:Search-Paths}
9350 \begin_inset Quotes sld
9354 \begin_inset Quotes srd
9359 \labelwidthstring 00.00.0000
9364 \begin_inset LatexCommand \index{SDCC\_LIB}
9371 \begin_inset LatexCommand \ref{sub:Search-Paths}
9377 \begin_inset Quotes sld
9381 \begin_inset Quotes srd
9386 \added_space_bottom bigskip
9387 There are some more environment variables recognized by SDCC, but these
9388 are solely used for debugging purposes.
9389 They can change or disappear very quickly, and will never be documented.
9392 Storage Class Language Extensions
9395 MCS51/DS390 Storage Class
9396 \begin_inset LatexCommand \index{Storage class}
9403 In addition to the ANSI storage classes SDCC allows the following MCS51
9404 specific storage classes:
9405 \layout Subsubsection
9408 \begin_inset LatexCommand \index{data (mcs51, ds390 storage class)}
9413 \begin_inset LatexCommand \index{\_\_data (mcs51, ds390 storage class)}
9418 \begin_inset LatexCommand \index{near (storage class)}
9423 \begin_inset LatexCommand \index{\_\_near (storage class)}
9434 storage class for the Small Memory model (
9442 or the more ANSI-C compliant forms
9450 can be used synonymously).
9451 Variables declared with this storage class will be allocated in the directly
9452 addressable portion of the internal RAM of a 8051, e.g.:
9457 __data unsigned char test_data;
9460 Writing 0x01 to this variable generates the assembly code:
9465 75*00 01\SpecialChar ~
9471 \layout Subsubsection
9474 \begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
9479 \begin_inset LatexCommand \index{\_\_xdata (mcs51, ds390 storage class)}
9484 \begin_inset LatexCommand \index{far (storage class)}
9489 \begin_inset LatexCommand \index{\_\_far (storage class)}
9496 Variables declared with this storage class will be placed in the external
9502 storage class for the Large Memory model, e.g.:
9507 __xdata unsigned char test_xdata;
9510 Writing 0x01 to this variable generates the assembly code:
9515 90s00r00\SpecialChar ~
9544 \layout Subsubsection
9547 \begin_inset LatexCommand \index{idata (mcs51, ds390 storage class)}
9552 \begin_inset LatexCommand \index{\_\_idata (mcs51, ds390 storage class)}
9559 Variables declared with this storage class will be allocated into the indirectly
9560 addressable portion of the internal ram of a 8051, e.g.:
9565 __idata unsigned char test_idata;
9568 Writing 0x01 to this variable generates the assembly code:
9597 Please note, the first 128 byte of idata physically access the same RAM
9599 The original 8051 had 128 byte idata memory, nowadays most devices have
9600 256 byte idata memory.
9602 \begin_inset LatexCommand \index{stack}
9606 is located in idata memory.
9607 \layout Subsubsection
9610 \begin_inset LatexCommand \index{pdata (mcs51, ds390 storage class)}
9615 \begin_inset LatexCommand \index{\_\_pdata (mcs51, ds390 storage class)}
9622 Paged xdata access is just as straightforward as using the other addressing
9624 It is typically located at the start of xdata and has a maximum size of
9626 The following example writes 0x01 to the pdata variable.
9627 Please note, pdata access physically accesses xdata memory.
9628 The high byte of the address is determined by port P2
9629 \begin_inset LatexCommand \index{P2 (mcs51 sfr)}
9633 (or in case of some 8051 variants by a separate Special Function Register,
9635 \begin_inset LatexCommand \ref{sub:MCS51-variants}
9644 storage class for the Medium Memory model, e.g.:
9649 __pdata unsigned char test_pdata;
9652 Writing 0x01 to this variable generates the assembly code:
9696 \begin_inset LatexCommand \index{-\/-xstack}
9700 option is used the pdata memory area is followed by the xstack memory area
9701 and the sum of their sizes is limited to 256 bytes.
9702 \layout Subsubsection
9705 \begin_inset LatexCommand \index{code}
9710 \begin_inset LatexCommand \index{\_\_code}
9717 'Variables' declared with this storage class will be placed in the code
9723 __code unsigned char test_code;
9726 Read access to this variable generates the assembly code:
9731 90s00r6F\SpecialChar ~
9734 mov dptr,#_test_code
9763 indexed arrays of characters in code memory can be accessed efficiently:
9768 __code char test_array[] = {'c','h','e','a','p'};
9771 Read access to this array using an 8-bit unsigned index generates the assembly
9788 90s00r41\SpecialChar ~
9791 mov dptr,#_test_array
9806 \layout Subsubsection
9809 \begin_inset LatexCommand \index{bit}
9814 \begin_inset LatexCommand \index{\_\_bit}
9821 This is a data-type and a storage class specifier.
9822 When a variable is declared as a bit, it is allocated into the bit addressable
9823 memory of 8051, e.g.:
9831 Writing 1 to this variable generates the assembly code:
9847 The bit addressable memory consists of 128 bits which are located from 0x20
9848 to 0x2f in data memory.
9851 Apart from this 8051 specific storage class most architectures support ANSI-C
9853 \begin_inset LatexCommand \index{bitfields}
9863 Not really meant as examples, but nevertheless showing what bitfields are
9864 about: device/include/mc68hc908qy.h and support/regression/tests/bitfields.c
9868 In accordance with ISO/IEC 9899 bits and bitfields without an explicit
9869 signed modifier are implemented as unsigned.
9870 \layout Subsubsection
9873 \begin_inset LatexCommand \index{sfr}
9878 \begin_inset LatexCommand \index{\_\_sfr}
9883 \begin_inset LatexCommand \index{sfr16}
9888 \begin_inset LatexCommand \index{\_\_sfr16}
9893 \begin_inset LatexCommand \index{sfr32}
9898 \begin_inset LatexCommand \index{\_\_sfr32}
9903 \begin_inset LatexCommand \index{\_\_sbit}
9908 \begin_inset LatexCommand \index{sbit}
9915 Like the bit keyword,
9917 sfr / sfr16 / sfr32 / sbit
9919 signify both a data-type and storage class, they are used to describe the
9940 variables of a 8051, eg:
9946 \begin_inset LatexCommand \index{at}
9951 \begin_inset LatexCommand \index{\_\_at}
9955 (0x80) P0;\SpecialChar ~
9956 /* special function register P0 at location 0x80 */
9960 /* 16 bit special function register combination for timer 0
9964 with the high byte at location 0x8C and the low byte at location 0x8A */
9966 __sfr16 __at (0x8C8A) TMR0;
9971 \begin_inset LatexCommand \index{at}
9976 \begin_inset LatexCommand \index{\_\_at}
9980 (0xd7) CY;\SpecialChar ~
9982 \begin_inset LatexCommand \index{Flags}
9987 \begin_inset LatexCommand \index{Carry flag}
9994 Special function registers which are located on an address dividable by
9995 8 are bit-addressable, an
9999 addresses a specific bit within these sfr.
10001 16 Bit and 32 bit special function register combinations which require a
10002 certain access order are better not declared using
10011 Allthough SDCC usually accesses them Least Significant Byte (LSB) first,
10012 this is not guaranteed.
10017 Please note, if you use a header file which was written for another compiler
10018 then the sfr / sfr16 / sfr32 / sbit Storage Class extensions will most
10024 Specifically the syntax
10027 sfr P0 = 0x80;\SpecialChar ~
10034 by SDCC to an assignment of 0x80 to a variable called P0
10037 \begin_inset Marginal
10051 Nevertheless it is possible to write header files
10052 \begin_inset LatexCommand \index{Header files}
10057 \begin_inset LatexCommand \index{Include files}
10061 which can be shared among different compilers (see section
10062 \begin_inset LatexCommand \ref{sec:Porting-code-to-other-compilers}
10068 \layout Subsubsection
10071 \begin_inset LatexCommand \index{Pointer}
10075 to MCS51/DS390 specific memory spaces
10078 SDCC allows (via language extensions) pointers to explicitly point to any
10079 of the memory spaces
10080 \begin_inset LatexCommand \index{Memory model}
10085 In addition to the explicit pointers, the compiler uses (by default) generic
10086 pointers which can be used to point to any of the memory spaces.
10090 Pointer declaration examples:
10095 /* pointer physically in internal ram pointing to object in external ram
10098 __xdata unsigned char * __data p;
10102 /* pointer physically in external ram pointing to object in internal ram
10105 __data unsigned char * __xdata p;
10109 /* pointer physically in code rom pointing to data in xdata space */
10111 __xdata unsigned char * __code p;
10115 /* pointer physically in code space pointing to data in code space */
10117 __code unsigned char * __code p;
10121 /* generic pointer physically located in xdata space */
10123 unsigned char * __xdata p;
10127 /* generic pointer physically located in default memory space */
10133 /* the following is a function pointer
10134 \begin_inset LatexCommand \index{function pointer}
10138 physically located in data space */
10140 char (* __data fp)(void);
10143 Well you get the idea.
10148 All unqualified pointers are treated as 3-byte (4-byte for the ds390)
10161 The highest order byte of the
10165 pointers contains the data space information.
10166 Assembler support routines are called whenever data is stored or retrieved
10172 These are useful for developing reusable library
10173 \begin_inset LatexCommand \index{Libraries}
10178 Explicitly specifying the pointer
10179 \begin_inset LatexCommand \index{pointer}
10183 type will generate the most efficient code.
10184 \layout Subsubsection
10186 Notes on MCS51 memory
10187 \begin_inset LatexCommand \index{MCS51 memory}
10194 The 8051 family of microcontrollers have a minimum of 128 bytes of internal
10195 RAM memory which is structured as follows:
10199 - Bytes 00-1F - 32 bytes to hold up to 4 banks of the registers R0 to R7,
10202 - Bytes 20-2F - 16 bytes to hold 128 bit
10203 \begin_inset LatexCommand \index{bit}
10209 - Bytes 30-7F - 80 bytes for general purpose use.
10214 Additionally some members of the MCS51 family may have up to 128 bytes of
10215 additional, indirectly addressable, internal RAM memory (
10220 \begin_inset LatexCommand \index{idata (mcs51, ds390 storage class)}
10225 \begin_inset LatexCommand \index{\_\_idata (mcs51, ds390 storage class)}
10230 Furthermore, some chips may have some built in external memory (
10235 \begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
10240 \begin_inset LatexCommand \index{\_\_xdata (mcs51, ds390 storage class)}
10244 ) which should not be confused with the internal, directly addressable RAM
10250 \begin_inset LatexCommand \index{data (mcs51, ds390 storage class)}
10255 \begin_inset LatexCommand \index{\_\_data (mcs51, ds390 storage class)}
10260 Sometimes this built in
10264 memory has to be activated before using it (you can probably find this
10265 information on the datasheet of the microcontroller your are using, see
10267 \begin_inset LatexCommand \ref{sub:Startup-Code}
10275 Normally SDCC will only use the first bank
10276 \begin_inset LatexCommand \index{register bank (mcs51, ds390)}
10280 of registers (register bank 0), but it is possible to specify that other
10281 banks of registers (keyword
10288 \begin_inset LatexCommand \index{using (mcs51, ds390 register bank)}
10293 \begin_inset LatexCommand \index{\_\_using (mcs51, ds390 register bank)}
10299 ) should be used in interrupt
10300 \begin_inset LatexCommand \index{interrupt}
10305 \begin_inset LatexCommand \index{\_\_interrupt}
10310 By default, the compiler will place the stack after the last byte of allocated
10311 memory for variables.
10312 For example, if the first 2 banks of registers are used, and only four
10317 variables, it will position the base of the internal stack at address 20
10319 This implies that as the stack
10320 \begin_inset LatexCommand \index{stack}
10324 grows, it will use up the remaining register banks, and the 16 bytes used
10325 by the 128 bit variables, and 80 bytes for general purpose use.
10326 If any bit variables are used, the data variables will be placed in unused
10327 register banks and after the byte holding the last bit variable.
10328 For example, if register banks 0 and 1 are used, and there are 9 bit variables
10333 variables will be placed starting from address 0x10 to 0x20 and continue
10346 \begin_inset LatexCommand \index{-\/-data-loc <Value>}
10350 to specify the start address of the
10365 \begin_inset LatexCommand \index{-\/-iram-size <Value>}
10369 to specify the size of the total internal RAM (
10383 By default the 8051 linker will place the stack after the last byte of (i)data
10396 \begin_inset LatexCommand \index{-\/-stack-loc <Value>}
10400 allows you to specify the start of the stack, i.e.
10401 you could start it after any data in the general purpose area.
10402 If your microcontroller has additional indirectly addressable internal
10407 ) you can place the stack on it.
10408 You may also need to use -
10419 \begin_inset LatexCommand \index{-\/-xdata-loc<Value>}
10423 to set the start address of the external RAM (
10438 \begin_inset LatexCommand \index{-\/-xram-size <Value>}
10442 to specify its size.
10443 Same goes for the code memory, using -
10454 \begin_inset LatexCommand \index{-\/-code-loc <Value>}
10469 \begin_inset LatexCommand \index{-\/-code-size <Value>}
10474 If in doubt, don't specify any options and see if the resulting memory
10475 layout is appropriate, then you can adjust it.
10477 \added_space_bottom bigskip
10478 The linker generates two files with memory allocation information.
10479 The first, with extension .map
10480 \begin_inset LatexCommand \index{<file>.map}
10484 shows all the variables and segments.
10485 The second with extension .mem
10486 \begin_inset LatexCommand \index{<file>.mem}
10490 shows the final memory layout.
10491 The linker will complain either if memory segments overlap, there is not
10492 enough memory, or there is not enough space for stack.
10493 If you get any linking warnings and/or errors related to stack or segments
10494 allocation, take a look at either the .map or .mem files to find out what
10496 The .mem file may even suggest a solution to the problem.
10499 Z80/Z180 Storage Class
10500 \begin_inset LatexCommand \index{Z80!Storage class}
10504 Language Extensions
10505 \layout Subsubsection
10508 \begin_inset LatexCommand \index{sfr}
10513 \begin_inset LatexCommand \index{\_\_sfr}
10517 (in/out to 8-bit addresses)
10521 \begin_inset LatexCommand \index{Z80}
10525 family has separate address spaces for memory and
10535 \begin_inset LatexCommand \index{I/O memory (Z80, Z180)}
10540 \begin_inset LatexCommand \index{Z80!I/O memory}
10545 \begin_inset LatexCommand \index{Z180!I/O memory}
10549 is accessed with special instructions, e.g.:
10554 sfr at 0x78 IoPort;\SpecialChar ~
10556 /* define a var in I/O space at 78h called IoPort */
10560 Writing 0x01 to this variable generates the assembly code:
10565 3E 01\SpecialChar ~
10573 D3 78\SpecialChar ~
10580 \layout Subsubsection
10583 \begin_inset LatexCommand \index{sfr}
10588 \begin_inset LatexCommand \index{\_\_sfr}
10592 (in/out to 16-bit addresses)
10599 is used to support 16 bit addresses in I/O memory e.g.:
10605 \begin_inset LatexCommand \index{at}
10610 \begin_inset LatexCommand \index{\_\_at}
10617 Writing 0x01 to this variable generates the assembly code:
10622 01 23 01\SpecialChar ~
10627 3E 01\SpecialChar ~
10635 ED 79\SpecialChar ~
10642 \layout Subsubsection
10645 \begin_inset LatexCommand \index{sfr}
10650 \begin_inset LatexCommand \index{\_\_sfr}
10654 (in0/out0 to 8 bit addresses on Z180
10655 \begin_inset LatexCommand \index{Z180}
10660 \begin_inset LatexCommand \index{HD64180 (see Z180)}
10666 \added_space_bottom bigskip
10667 The compiler option -
10678 \begin_inset LatexCommand \index{Z180!Options!-\/-portmode}
10682 =180 (80) and a compiler #pragma\SpecialChar ~
10684 \begin_inset LatexCommand \index{Z180!Pragmas!\#pragma portmode}
10688 z180 (z80) is used to turn on (off) the Z180/HD64180 port addressing instructio
10698 If you include the file z180.h this will be set automatically.
10702 \begin_inset LatexCommand \index{HC08!Storage class}
10706 Language Extensions
10707 \layout Subsubsection
10710 \begin_inset LatexCommand \index{data (hc08 storage class)}
10715 \begin_inset LatexCommand \index{\_\_data (hc08 storage class)}
10722 The data storage class declares a variable that resides in the first 256
10723 bytes of memory (the direct page).
10725 \begin_inset LatexCommand \index{HC08}
10729 is most efficient at accessing variables (especially pointers) stored here.
10730 \layout Subsubsection
10733 \begin_inset LatexCommand \index{xdata (hc08 storage class)}
10738 \begin_inset LatexCommand \index{\_\_xdata (hc08 storage class)}
10744 \added_space_bottom bigskip
10745 The xdata storage class declares a variable that can reside anywhere in
10747 This is the default if no storage class is specified.
10751 Absolute Addressing
10752 \begin_inset LatexCommand \index{Absolute addressing}
10759 Data items can be assigned an absolute address with the
10762 \begin_inset LatexCommand \index{at}
10767 \begin_inset LatexCommand \index{\_\_at}
10773 keyword, in addition to a storage class, e.g.:
10779 \begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
10784 \begin_inset LatexCommand \index{\_\_xdata (mcs51, ds390 storage class)}
10789 \begin_inset LatexCommand \index{at}
10794 \begin_inset LatexCommand \index{\_\_at}
10798 0x7ffe unsigned int chksum;
10801 or, better conforming to ISO/IEC 9899 C:
10806 __xdata __at (0x7ffe) unsigned int chksum;
10809 In the above example the variable chksum will be located at 0x7ffe and 0x7fff
10810 of the external ram.
10815 reserve any space for variables declared in this way
10816 \begin_inset Marginal
10827 (they are implemented with an equate in the assembler).
10828 Thus it is left to the programmer to make sure there are no overlaps with
10829 other variables that are declared without the absolute address.
10830 The assembler listing file (.lst
10831 \begin_inset LatexCommand \index{<file>.lst}
10835 ) and the linker output files (.rst
10836 \begin_inset LatexCommand \index{<file>.rst}
10841 \begin_inset LatexCommand \index{<file>.map}
10845 ) are good places to look for such overlaps.
10846 Variables with an absolute address are
10849 \begin_inset Marginal
10863 \begin_inset LatexCommand \index{Variable initialization}
10870 In case of memory mapped I/O devices the keyword
10874 has to be used to tell the compiler that accesses might not be removed:
10880 \begin_inset LatexCommand \index{volatile}
10885 \begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
10890 \begin_inset LatexCommand \index{at}
10894 (0x8000) unsigned char PORTA_8255;
10897 For some architectures (mcs51) array accesses are more efficient if an (xdata/fa
10902 \begin_inset LatexCommand \index{Aligned array}
10909 starts at a block (256 byte) boundary
10910 \begin_inset LatexCommand \index{block boundary}
10915 \begin_inset LatexCommand \ref{sub:A-Step-by Assembler Introduction}
10921 Absolute addresses can be specified for variables in all storage classes,
10928 \begin_inset LatexCommand \index{bit}
10933 \begin_inset LatexCommand \index{at}
10940 The above example will allocate the variable at offset 0x02 in the bit-addressab
10942 There is no real advantage to assigning absolute addresses to variables
10943 in this manner, unless you want strict control over all the variables allocated.
10944 One possible use would be to write hardware portable code.
10945 For example, if you have a routine that uses one or more of the microcontroller
10946 I/O pins, and such pins are different for two different hardwares, you
10947 can declare the I/O pins in your routine using:
10953 \begin_inset LatexCommand \index{volatile}
10957 __bit MOSI;\SpecialChar ~
10961 /* master out, slave in */
10963 extern volatile __bit MISO;\SpecialChar ~
10967 /* master in, slave out */
10969 extern volatile __bit MCLK;\SpecialChar ~
10977 /* Input and Output of a byte on a 3-wire serial bus.
10982 If needed adapt polarity of clock, polarity of data and bit order
10987 unsigned char spi_io(unsigned char out_byte)
11011 MOSI = out_byte & 0x80;
11041 /* _asm nop _endasm; */\SpecialChar ~
11049 /* for slow peripherals */
11100 Then, someplace in the code for the first hardware you would use
11106 \begin_inset LatexCommand \index{at}
11111 \begin_inset LatexCommand \index{\_\_at}
11115 (0x80) MOSI;\SpecialChar ~
11119 /* I/O port 0, bit 0 */
11121 __bit __at (0x81) MISO;\SpecialChar ~
11125 /* I/O port 0, bit 1 */
11127 __bit __at (0x82) MCLK;\SpecialChar ~
11131 /* I/O port 0, bit 2 */
11134 Similarly, for the second hardware you would use
11139 __bit __at (0x83) MOSI;\SpecialChar ~
11143 /* I/O port 0, bit 3 */
11145 __bit __at (0x91) MISO;\SpecialChar ~
11149 /* I/O port 1, bit 1 */
11152 \begin_inset LatexCommand \index{bit}
11156 __at (0x92) MCLK;\SpecialChar ~
11160 /* I/O port 1, bit 2 */
11162 \added_space_bottom bigskip
11163 and you can use the same hardware dependent routine without changes, as
11164 for example in a library.
11165 This is somehow similar to sbit, but only one absolute address has to be
11166 specified in the whole project.
11170 \begin_inset LatexCommand \index{Parameters}
11175 \begin_inset LatexCommand \index{function parameter}
11180 \begin_inset LatexCommand \index{local variables}
11185 \begin_inset LatexCommand \label{sec:Parameters-and-Local-Variables}
11192 Automatic (local) variables and parameters to functions can either be placed
11193 on the stack or in data-space.
11194 The default action of the compiler is to place these variables in the internal
11195 RAM (for small model) or external RAM (for large model).
11196 This in fact makes them similar to
11199 \begin_inset LatexCommand \index{static}
11205 so by default functions are non-reentrant
11206 \begin_inset LatexCommand \index{reentrant}
11215 They can be placed on the stack
11216 \begin_inset LatexCommand \index{stack}
11233 \begin_inset LatexCommand \index{-\/-stack-auto}
11241 #pragma\SpecialChar ~
11245 \begin_inset LatexCommand \index{\#pragma stackauto}
11252 \begin_inset LatexCommand \index{reentrant}
11258 keyword in the function declaration, e.g.:
11263 unsigned char foo(char i) __reentrant
11277 Since stack space on 8051 is limited, the
11295 option should be used sparingly.
11296 Note that the reentrant keyword just means that the parameters & local
11297 variables will be allocated to the stack, it
11301 mean that the function is register bank
11302 \begin_inset LatexCommand \index{register bank (mcs51, ds390)}
11311 \begin_inset LatexCommand \index{local variables}
11315 can be assigned storage classes and absolute
11316 \begin_inset LatexCommand \index{Absolute addressing}
11325 unsigned char foo()
11333 __xdata unsigned char i;
11346 \begin_inset LatexCommand \index{at}
11350 (0x31) unsigned char j;
11362 In the above example the variable
11366 will be allocated in the external ram,
11370 in bit addressable space and
11389 or when a function is declared as
11393 this should only be done for static variables.
11397 \begin_inset LatexCommand \index{function parameter}
11401 however are not allowed any storage class
11402 \begin_inset LatexCommand \index{Storage class}
11406 , (storage classes for parameters will be ignored), their allocation is
11407 governed by the memory model in use, and the reentrancy options.
11410 It is however allowed to use bit parameters in reentrant functions and also
11411 non-static local bit variables are supported.
11412 Efficient use is limited to 8 semi-bitregisters in bit space.
11413 They are pushed and popped to stack
11414 \begin_inset LatexCommand \index{stack}
11418 as a single byte just like the normal registers.
11422 \begin_inset LatexCommand \label{sub:Overlaying}
11427 \begin_inset LatexCommand \index{Overlaying}
11435 \begin_inset LatexCommand \index{reentrant}
11439 functions SDCC will try to reduce internal ram space usage by overlaying
11440 parameters and local variables of a function (if possible).
11441 Parameters and local variables
11442 \begin_inset LatexCommand \index{local variables}
11446 of a function will be allocated to an overlayable segment if the function
11449 no other function calls and the function is non-reentrant and the memory
11451 \begin_inset LatexCommand \index{Memory model}
11458 If an explicit storage class
11459 \begin_inset LatexCommand \index{Storage class}
11463 is specified for a local variable, it will NOT be overlayed.
11466 Note that the compiler (not the linkage editor) makes the decision for overlayin
11468 Functions that are called from an interrupt service routine
11469 \begin_inset Marginal
11479 should be preceded by a #pragma\SpecialChar ~
11481 \begin_inset LatexCommand \index{\#pragma nooverlay}
11485 if they are not reentrant.
11488 Also note that the compiler does not do any processing of inline assembler
11489 code, so the compiler might incorrectly assign local variables and parameters
11490 of a function into the overlay segment if the inline assembler code calls
11491 other c-functions that might use the overlay.
11492 In that case the #pragma\SpecialChar ~
11493 nooverlay should be used.
11496 Parameters and local variables of functions that contain 16 or 32 bit multiplica
11498 \begin_inset LatexCommand \index{Multiplication}
11503 \begin_inset LatexCommand \index{Division}
11507 will NOT be overlayed since these are implemented using external functions,
11516 \begin_inset LatexCommand \index{\#pragma nooverlay}
11522 void set_error(unsigned char errcd)
11538 void some_isr () __interrupt
11539 \begin_inset LatexCommand \index{interrupt}
11568 \added_space_bottom bigskip
11569 In the above example the parameter
11577 would be assigned to the overlayable segment if the #pragma\SpecialChar ~
11579 not present, this could cause unpredictable runtime behavior when called
11580 from an interrupt service routine.
11581 The #pragma\SpecialChar ~
11582 nooverlay ensures that the parameters and local variables for
11583 the function are NOT overlayed.
11586 Interrupt Service Routines
11587 \begin_inset LatexCommand \label{sub:Interrupt-Service-Routines}
11594 General Information
11609 outines to be coded in C, with some extended keywords.
11614 void timer_isr (void) __interrupt (1) __using (1)
11628 The optional number following the
11631 \begin_inset LatexCommand \index{interrupt}
11636 \begin_inset LatexCommand \index{\_\_interrupt}
11642 keyword is the interrupt number this routine will service.
11643 When present, the compiler will insert a call to this routine in the interrupt
11645 \begin_inset LatexCommand \index{interrupt vector table}
11649 for the interrupt number specified.
11650 If you have multiple source files in your project, interrupt service routines
11651 can be present in any of them, but a prototype of the isr MUST be present
11652 or included in the file that contains the function
11657 The optional (8051 specific) keyword
11660 \begin_inset LatexCommand \index{using (mcs51, ds390 register bank)}
11665 \begin_inset LatexCommand \index{\_\_using (mcs51, ds390 register bank)}
11671 can be used to tell the compiler to use the specified register bank when
11672 generating code for this function.
11675 Interrupt service routines open the door for some very interesting bugs:
11676 \layout Subsubsection
11679 \begin_inset LatexCommand \label{sub:Common-interrupt-pitfall-volatile}
11683 Common interrupt pitfall: variable not declared
11688 If an interrupt service routine changes variables which are accessed by
11689 other functions these variables have to be declared
11694 \begin_inset LatexCommand \index{volatile}
11700 \begin_inset LatexCommand \url{http://en.wikipedia.org/wiki/Volatile_variable}
11705 \layout Subsubsection
11708 \begin_inset LatexCommand \label{sub:Common-interrupt-pitfall-non-atomic}
11712 Common interrupt pitfall:
11717 If the access to these variables is not
11720 \begin_inset LatexCommand \index{atomic}
11727 the processor needs more than one instruction for the access and could
11728 be interrupted while accessing the variable) the interrupt must be disabled
11729 during the access to avoid inconsistent data.
11732 Access to 16 or 32 bit variables is obviously not atomic on 8 bit CPUs and
11733 should be protected by disabling interrupts.
11734 You're not automatically on the safe side if you use 8 bit variables though.
11735 We need an example here: f.e.
11736 on the 8051 the harmless looking
11737 \begin_inset Quotes srd
11742 flags\SpecialChar ~
11747 \begin_inset Quotes sld
11756 \begin_inset Quotes srd
11761 flags\SpecialChar ~
11766 \begin_inset Quotes sld
11769 from within an interrupt routine might get lost if the interrupt occurs
11772 \begin_inset Quotes sld
11777 counter\SpecialChar ~
11782 \begin_inset Quotes srd
11785 is not atomic on the 8051 even if
11789 is located in data memory.
11791 Bugs like these are hard to reproduce and can cause a lot of trouble.
11793 \layout Subsubsection
11796 \begin_inset LatexCommand \label{sub:Common-interrupt-pitfall-stack-overflow}
11800 Common interrupt pitfall:
11805 The return address and the registers used in the interrupt service routine
11806 are saved on the stack
11807 \begin_inset LatexCommand \index{stack}
11811 so there must be sufficient stack space.
11812 If there isn't variables or registers (or even the return address itself)
11819 \begin_inset LatexCommand \index{stack overflow}
11823 is most likely to happen if the interrupt occurs during the
11824 \begin_inset Quotes sld
11828 \begin_inset Quotes srd
11831 subroutine when the stack is already in use for f.e.
11832 many return addresses.
11833 \layout Subsubsection
11836 \begin_inset LatexCommand \label{sub:Common-interrupt-pitfall-non-reentrant}
11840 Common interrupt pitfall:
11842 use of non-reentrant functions
11845 A special note here, int (16 bit) and long (32 bit) integer division
11846 \begin_inset LatexCommand \index{Division}
11851 \begin_inset LatexCommand \index{Multiplication}
11856 \begin_inset LatexCommand \index{Modulus}
11861 \begin_inset LatexCommand \index{Floating point support}
11865 operations are implemented using external support routines.
11866 If an interrupt service routine needs to do any of these operations then
11867 the support routines (as mentioned in a following section) will have to
11868 be recompiled using the
11881 \begin_inset LatexCommand \index{-\/-stack-auto}
11887 option and the source file will need to be compiled using the
11902 \begin_inset LatexCommand \index{-\/-int-long-reent}
11909 Note, the type promotion
11910 \begin_inset LatexCommand \index{type promotion}
11914 required by ANSI C can cause 16 bit routines to be used
11915 \begin_inset Marginal
11926 without the programmer being aware of it.
11930 (unsigned char)(tail-1)
11932 within the if clause in section
11933 \begin_inset LatexCommand \ref{sub:A-Step-by Assembler Introduction}
11939 \added_space_bottom bigskip
11940 Calling other functions from an interrupt service routine is not recommended,
11941 avoid it if possible.
11942 Note that when some function is called from an interrupt service routine
11943 it should be preceded by a #pragma\SpecialChar ~
11945 \begin_inset LatexCommand \index{\#pragma nooverlay}
11949 if it is not reentrant.
11950 Furthermore nonreentrant functions should not be called from the main program
11951 while the interrupt service routine might be active.
11952 They also must not be called from low priority interrupt service routines
11953 while a high priority interrupt service routine might be active.
11954 You could use semaphores or make the function
11958 if all parameters are passed in registers.
11961 \begin_inset LatexCommand \ref{sub:Overlaying}
11966 about Overlaying and section
11967 \begin_inset LatexCommand \ref{sub:Functions-using-private-banks}
11972 about Functions using private register banks.
11975 MCS51/DS390 Interrupt Service Routines
11979 \begin_inset LatexCommand \index{interrupt}
11983 numbers and the corresponding address & descriptions for the Standard 8051/8052
11985 SDCC will automatically adjust the
11986 \begin_inset LatexCommand \index{interrupt vector table}
11990 to the maximum interrupt number specified.
11996 \begin_inset Tabular
11997 <lyxtabular version="3" rows="9" columns="3">
11999 <column alignment="center" valignment="top" leftline="true" width="0in">
12000 <column alignment="left" valignment="top" leftline="true" width="0in">
12001 <column alignment="left" valignment="top" leftline="true" rightline="true" width="0in">
12002 <row topline="true" bottomline="true">
12003 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
12011 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
12019 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
12028 <row topline="true">
12029 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
12037 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
12045 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
12054 <row topline="true">
12055 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
12063 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
12071 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
12080 <row topline="true">
12081 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
12089 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
12097 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
12106 <row topline="true">
12107 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
12115 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
12123 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
12132 <row topline="true">
12133 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
12141 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
12149 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
12158 <row topline="true">
12159 <cell multicolumn="1" alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
12167 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
12175 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
12184 <row topline="true">
12185 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
12193 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
12200 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
12209 <row topline="true" bottomline="true">
12210 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
12218 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
12225 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
12243 If the interrupt service routine is defined without
12246 \begin_inset LatexCommand \index{using (mcs51, ds390 register bank)}
12251 \begin_inset LatexCommand \index{\_\_using (mcs51, ds390 register bank)}
12257 a register bank or with register bank 0 (
12261 0), the compiler will save the registers used by itself on the stack upon
12262 entry and restore them at exit, however if such an interrupt service routine
12263 calls another function then the entire register bank will be saved on the
12265 This scheme may be advantageous for small interrupt service routines which
12266 have low register usage.
12268 \added_space_bottom bigskip
12269 If the interrupt service routine is defined to be using a specific register
12274 & psw are saved and restored, if such an interrupt service routine calls
12275 another function (using another register bank) then the entire register
12276 bank of the called function will be saved on the stack
12277 \begin_inset LatexCommand \index{stack}
12282 This scheme is recommended for larger interrupt service routines.
12286 \begin_inset LatexCommand \index{HC08}
12290 Interrupt Service Routines
12292 \added_space_bottom bigskip
12293 Since the number of interrupts
12294 \begin_inset LatexCommand \index{HC08!interrupt}
12298 available is chip specific and the interrupt vector table always ends at
12299 the last byte of memory, the interrupt numbers corresponds to the interrupt
12300 vectors in reverse order of address.
12301 For example, interrupt 1 will use the interrupt vector at 0xfffc, interrupt
12302 2 will use the interrupt vector at 0xfffa, and so on.
12303 However, interrupt 0 (the reset vector at 0xfffe) is not redefinable in
12304 this way; instead see section
12305 \begin_inset LatexCommand \ref{sub:Startup-Code}
12309 for details on customizing startup.
12312 Z80 Interrupt Service Routines
12316 \begin_inset LatexCommand \index{Z80}
12320 uses several different methods for determining the correct interrupt
12321 \begin_inset LatexCommand \index{Z80!interrupt}
12325 vector depending on the hardware implementation.
12326 Therefore, SDCC ignores the optional interrupt number and does not attempt
12327 to generate an interrupt vector table.
12330 By default, SDCC generates code for a maskable interrupt, which uses a RETI
12331 instruction to return from the interrupt.
12332 To write an interrupt handler for the non-maskable interrupt, which needs
12333 a RETN instruction instead, add the
12342 void nmi_isr (void) critical interrupt
12355 \added_space_bottom bigskip
12356 However if you need to create a non-interruptable interrupt service routine
12357 you would also require the
12362 To distinguish between this and an nmi_isr you must provide an interrupt
12366 Enabling and Disabling Interrupts
12369 Critical Functions and Critical Statements
12372 A special keyword may be associated with a block or a function declaring
12378 SDCC will generate code to disable all interrupts
12379 \begin_inset LatexCommand \index{interrupt}
12383 upon entry to a critical function and restore the interrupt enable to the
12384 previous state before returning.
12385 Nesting critical functions will need one additional byte on the stack
12386 \begin_inset LatexCommand \index{stack}
12395 int foo () __critical
12396 \begin_inset LatexCommand \index{critical}
12401 \begin_inset LatexCommand \index{\_\_critical}
12426 The critical attribute maybe used with other attributes like
12436 may also be used to disable interrupts more locally:
12444 More than one statement could have been included in the block.
12447 Enabling and Disabling Interrupts directly
12451 \begin_inset LatexCommand \index{interrupt}
12455 can also be disabled and enabled directly (8051):
12460 EA = 0;\SpecialChar ~
12523 EA = 1;\SpecialChar ~
12590 On other architectures which have seperate opcodes for enabling and disabling
12591 interrupts you might want to make use of defines with inline assembly
12592 \begin_inset LatexCommand \index{Assembler routines}
12597 \begin_inset LatexCommand \index{HC08!interrupt}
12607 \begin_inset LatexCommand \index{\_asm}
12616 \begin_inset LatexCommand \index{\_endasm}
12625 #define SEI _asm\SpecialChar ~
12637 Note: it is sometimes sufficient to disable only a specific interrupt source
12639 a timer or serial interrupt by manipulating an
12642 \begin_inset LatexCommand \index{interrupt mask}
12652 Usually the time during which interrupts are disabled should be kept as
12654 This minimizes both
12659 \begin_inset LatexCommand \index{interrupt latency}
12663 (the time between the occurrence of the interrupt and the execution of
12664 the first code in the interrupt routine) and
12669 \begin_inset LatexCommand \index{interrupt jitter}
12673 (the difference between the shortest and the longest interrupt latency).
12674 These really are something different, f.e.
12675 a serial interrupt has to be served before its buffer overruns so it cares
12676 for the maximum interrupt latency, whereas it does not care about jitter.
12677 On a loudspeaker driven via a digital to analog converter which is fed
12678 by an interrupt a latency of a few milliseconds might be tolerable, whereas
12679 a much smaller jitter will be very audible.
12682 You can reenable interrupts within an interrupt routine and on some architecture
12683 s you can make use of two (or more) levels of
12685 interrupt priorities
12688 \begin_inset LatexCommand \index{interrupt priority}
12693 On some architectures which don't support interrupt priorities these can
12694 be implemented by manipulating the interrupt mask and reenabling interrupts
12695 within the interrupt routine.
12696 Check there is sufficient space on the stack
12697 \begin_inset LatexCommand \index{stack}
12701 and don't add complexity unless you have to.
12706 \begin_inset LatexCommand \index{semaphore}
12710 locking (mcs51/ds390)
12713 Some architectures (mcs51/ds390) have an atomic
12714 \begin_inset LatexCommand \index{atomic}
12727 These type of instructions are typically used in preemptive multitasking
12728 systems, where a routine f.e.
12729 claims the use of a data structure ('acquires a lock
12730 \begin_inset LatexCommand \index{lock}
12734 on it'), makes some modifications and then releases the lock when the data
12735 structure is consistent again.
12736 The instruction may also be used if interrupt and non-interrupt code have
12737 to compete for a resource.
12738 With the atomic bit test and clear instruction interrupts
12739 \begin_inset LatexCommand \index{interrupt}
12743 don't have to be disabled for the locking operation.
12747 SDCC generates this instruction if the source follows this pattern:
12753 \begin_inset LatexCommand \index{volatile}
12757 bit resource_is_free;
12761 if (resource_is_free)
12771 resource_is_free=0;
12784 resource_is_free=1;
12791 Note, mcs51 and ds390 support only an atomic
12792 \begin_inset LatexCommand \index{atomic}
12800 instruction (as opposed to atomic bit test and
12805 Functions using private register banks
12806 \begin_inset LatexCommand \label{sub:Functions-using-private-banks}
12813 Some architectures have support for quickly changing register sets.
12814 SDCC supports this feature with the
12817 \begin_inset LatexCommand \index{using (mcs51, ds390 register bank)}
12822 \begin_inset LatexCommand \index{\_\_using (mcs51, ds390 register bank)}
12828 attribute (which tells the compiler to use a register bank
12829 \begin_inset LatexCommand \index{register bank (mcs51, ds390)}
12833 other than the default bank zero).
12834 It should only be applied to
12837 \begin_inset LatexCommand \index{interrupt}
12843 functions (see footnote below).
12844 This will in most circumstances make the generated ISR code more efficient
12845 since it will not have to save registers on the stack.
12852 attribute will have no effect on the generated code for a
12856 function (but may occasionally be useful anyway
12862 possible exception: if a function is called ONLY from 'interrupt' functions
12863 using a particular bank, it can be declared with the same 'using' attribute
12864 as the calling 'interrupt' functions.
12865 For instance, if you have several ISRs using bank one, and all of them
12866 call memcpy(), it might make sense to create a specialized version of memcpy()
12867 'using 1', since this would prevent the ISR from having to save bank zero
12868 to the stack on entry and switch to bank zero before calling the function
12875 (pending: Note, nowadays the
12879 attribute has an effect on
12883 the generated code for a
12898 function using a non-zero bank will assume that it can trash that register
12899 bank, and will not save it.
12900 Since high-priority interrupts
12901 \begin_inset LatexCommand \index{interrupts}
12906 \begin_inset LatexCommand \index{interrupt priority}
12910 can interrupt low-priority ones on the 8051 and friends, this means that
12911 if a high-priority ISR
12915 a particular bank occurs while processing a low-priority ISR
12919 the same bank, terrible and bad things can happen.
12920 To prevent this, no single register bank should be
12924 by both a high priority and a low priority ISR.
12925 This is probably most easily done by having all high priority ISRs use
12926 one bank and all low priority ISRs use another.
12927 If you have an ISR which can change priority at runtime, you're on your
12928 own: I suggest using the default bank zero and taking the small performance
12931 \added_space_bottom bigskip
12932 It is most efficient if your ISR calls no other functions.
12933 If your ISR must call other functions, it is most efficient if those functions
12934 use the same bank as the ISR (see note 1 below); the next best is if the
12935 called functions use bank zero.
12936 It is very inefficient to call a function using a different, non-zero bank
12942 \begin_inset LatexCommand \label{sub:Startup-Code}
12947 \begin_inset LatexCommand \index{Startup code}
12954 MCS51/DS390 Startup Code
12957 The compiler inserts a call to the C routine
12959 _sdcc_external_startup()
12960 \begin_inset LatexCommand \index{\_sdcc\_external\_startup()}
12969 at the start of the CODE area.
12970 This routine is in the runtime library
12971 \begin_inset LatexCommand \index{Runtime library}
12976 By default this routine returns 0, if this routine returns a non-zero value,
12977 the static & global variable initialization will be skipped and the function
12978 main will be invoked.
12979 Otherwise static & global variables will be initialized before the function
12983 _sdcc_external_startup()
12985 routine to your program to override the default if you need to setup hardware
12986 or perform some other critical operation prior to static & global variable
12988 \begin_inset LatexCommand \index{Variable initialization}
12993 On some mcs51 variants xdata
12994 \begin_inset LatexCommand \index{xdata (mcs51, ds390 storage class)}
12998 memory has to be explicitly enabled before it can be accessed or if the
13000 \begin_inset LatexCommand \index{watchdog}
13004 needs to be disabled, this is the place to do it.
13005 The startup code clears all internal data memory, 256 bytes by default,
13006 but from 0 to n-1 if
13019 \begin_inset LatexCommand \index{-\/-iram-size <Value>}
13026 (recommended for Chipcon CC1010).
13028 \added_space_bottom bigskip
13029 See also the compiler options
13048 \begin_inset LatexCommand \index{-\/-no-xinit-opt}
13067 \begin_inset LatexCommand \index{-\/-main-return}
13072 \begin_inset LatexCommand \ref{sub:MCS51-variants}
13076 about MCS51-variants.
13081 \added_space_bottom bigskip
13083 \begin_inset LatexCommand \index{HC08}
13087 startup code follows the same scheme as the MCS51 startup code.
13092 \added_space_bottom bigskip
13094 \begin_inset LatexCommand \index{Z80}
13098 the startup code is inserted by linking with crt0.o which is generated from
13099 sdcc/device/lib/z80/crt0.s.
13100 If you need a different startup code you can use the compiler option
13121 \begin_inset LatexCommand \index{-\/-no-std-crt0}
13125 and provide your own crt0.o.
13129 Inline Assembler Code
13130 \begin_inset LatexCommand \index{Assembler routines}
13137 A Step by Step Introduction
13138 \begin_inset LatexCommand \label{sub:A-Step-by Assembler Introduction}
13145 Starting from a small snippet of c-code this example shows for the MCS51
13146 how to use inline assembly, access variables, a function parameter and
13147 an array in xdata memory.
13148 The example uses an MCS51 here but is easily adapted for other architectures.
13149 This is a buffer routine which should be optimized:
13155 unsigned char __far
13156 \begin_inset LatexCommand \index{far (storage class)}
13161 \begin_inset LatexCommand \index{\_\_far (storage class)}
13166 \begin_inset LatexCommand \index{at}
13171 \begin_inset LatexCommand \index{\_\_at}
13175 (0x7f00) buf[0x100];
13176 \begin_inset LatexCommand \index{Aligned array}
13182 unsigned char head, tail;\SpecialChar ~
13200 \begin_inset LatexCommand \index{interrupt}
13252 \begin_inset LatexCommand \ref{sub:Common-interrupt-pitfall-volatile}
13264 void to_buffer( unsigned char c )
13272 if( head != (unsigned char)(tail-1) )\SpecialChar ~
13278 \begin_inset LatexCommand \index{promotion to signed int}
13283 \begin_inset LatexCommand \index{type promotion}
13288 \begin_inset Marginal
13309 buf[ head++ ] = c;\SpecialChar ~
13325 /* access to a 256 byte aligned array */
13330 If the code snippet (assume it is saved in buffer.c) is compiled with SDCC
13331 then a corresponding buffer.asm file is generated.
13332 We define a new function
13336 in file buffer.c in which we cut and paste the generated code, removing
13337 unwanted comments and some ':'.
13339 \begin_inset Quotes sld
13343 \begin_inset Quotes srd
13347 \begin_inset Quotes sld
13351 \begin_inset Quotes srd
13354 to the beginning and the end of the function body:
13360 /* With a cut and paste from the .asm file, we have something to start with.
13365 The function is not yet OK! (registers aren't saved) */
13367 void to_buffer_asm( unsigned char c )
13376 \begin_inset LatexCommand \index{\_asm}
13381 \begin_inset LatexCommand \index{\_\_asm}
13395 ;buffer.c if( head != (unsigned char)(tail-1) ) \SpecialChar ~
13401 \begin_inset LatexCommand \index{promotion to signed int}
13406 \begin_inset LatexCommand \index{type promotion}
13458 ;buffer.c buf[ head++ ] = c; /* access to a 256 byte aligned array */
13459 \begin_inset LatexCommand \index{Aligned array}
13524 \begin_inset LatexCommand \index{\_endasm}
13529 \begin_inset LatexCommand \index{\_\_endasm}
13538 The new file buffer.c should compile with only one warning about the unreferenced
13539 function argument 'c'.
13540 Now we hand-optimize the assembly code and insert an #define USE_ASSEMBLY
13541 (1) and finally have:
13547 unsigned char __far __at(0x7f00) buf[0x100];
13549 unsigned char head, tail;
13551 #define USE_ASSEMBLY (1)
13559 void to_buffer( unsigned char c )
13567 if( head != (unsigned char)(tail-1) )
13587 void to_buffer( unsigned char c )
13595 c; // to avoid warning: unreferenced function argument
13602 \begin_inset LatexCommand \index{\_asm}
13607 \begin_inset LatexCommand \index{\_\_asm}
13621 ; save used registers here.
13632 ; If we were still using r2,r3 we would have to push them here.
13635 ; if( head != (unsigned char)(tail-1) )
13678 ; we could do an ANL a,#0x0f here to use a smaller buffer (see below)
13702 ; buf[ head++ ] = c;
13713 a,dpl \SpecialChar ~
13720 ; dpl holds lower byte of function argument
13731 dpl,_head \SpecialChar ~
13734 ; buf is 0x100 byte aligned so head can be used directly
13776 ; we could do an ANL _head,#0x0f here to use a smaller buffer (see above)
13788 ; restore used registers here
13795 \begin_inset LatexCommand \index{\_endasm}
13800 \begin_inset LatexCommand \index{\_\_endasm}
13811 The inline assembler code can contain any valid code understood by the assembler
13812 , this includes any assembler directives and comment lines.
13813 The assembler does not like some characters like ':' or ''' in comments.
13814 You'll find an 100+ pages assembler manual in sdcc/as/doc/asxhtm.html
13815 \begin_inset LatexCommand \index{asXXXX (as-gbz80, as-hc08, asx8051, as-z80)}
13820 \begin_inset LatexCommand \index{Assembler documentation}
13825 \begin_inset LatexCommand \url{http://svn.sourceforge.net/viewvc/*checkout*/sdcc/trunk/sdcc/as/doc/asxhtm.html}
13833 The compiler does not do any validation of the code within the
13836 \begin_inset LatexCommand \index{\_asm}
13841 \begin_inset LatexCommand \index{\_\_asm}
13849 \begin_inset LatexCommand \index{\_endasm}
13854 \begin_inset LatexCommand \index{\_\_endasm}
13863 Specifically it will not know which registers are used and thus register
13865 \begin_inset LatexCommand \index{push/pop}
13869 has to be done manually.
13873 It is recommended that each assembly instruction (including labels) be placed
13874 in a separate line (as the example shows).
13888 \begin_inset LatexCommand \index{-\/-peep-asm}
13894 command line option is used, the inline assembler code will be passed through
13895 the peephole optimizer
13896 \begin_inset LatexCommand \index{Peephole optimizer}
13901 There are only a few (if any) cases where this option makes sense, it might
13902 cause some unexpected changes in the inline assembler code.
13903 Please go through the peephole optimizer rules defined in file
13907 before using this option.
13911 \begin_inset LatexCommand \label{sub:Naked-Functions}
13916 \begin_inset LatexCommand \index{Naked functions}
13923 A special keyword may be associated with a function declaring it as
13926 \begin_inset LatexCommand \index{\_naked}
13931 \begin_inset LatexCommand \index{\_\_naked}
13942 function modifier attribute prevents the compiler from generating prologue
13943 \begin_inset LatexCommand \index{function prologue}
13948 \begin_inset LatexCommand \index{function epilogue}
13952 code for that function.
13953 This means that the user is entirely responsible for such things as saving
13954 any registers that may need to be preserved, selecting the proper register
13955 bank, generating the
13959 instruction at the end, etc.
13960 Practically, this means that the contents of the function must be written
13961 in inline assembler.
13962 This is particularly useful for interrupt functions, which can have a large
13963 (and often unnecessary) prologue/epilogue.
13964 For example, compare the code generated by these two functions:
13970 \begin_inset LatexCommand \index{volatile}
13974 data unsigned char counter;
13978 void simpleInterrupt(void) __interrupt
13979 \begin_inset LatexCommand \index{interrupt}
13984 \begin_inset LatexCommand \index{\_\_interrupt}
14002 void nakedInterrupt(void) __interrupt (2) __naked
14011 \begin_inset LatexCommand \index{\_asm}
14016 \begin_inset LatexCommand \index{\_\_asm}
14033 _counter ; does not change flags, no need to save psw
14045 ; MUST explicitly include ret or reti in _naked function.
14052 \begin_inset LatexCommand \index{\_endasm}
14057 \begin_inset LatexCommand \index{\_\_endasm}
14066 For an 8051 target, the generated simpleInterrupt looks like:
14075 example, recent versions of SDCC generate
14081 code for simpleInterrupt() and nakedInterrupt()!
14221 whereas nakedInterrupt looks like:
14236 _counter ; does not change flags, no need to save psw
14254 ; MUST explicitly include ret or reti in _naked function
14257 The related directive #pragma exclude
14258 \begin_inset LatexCommand \index{\#pragma exclude}
14262 allows a more fine grained control over pushing & popping
14263 \begin_inset LatexCommand \index{push/pop}
14270 While there is nothing preventing you from writing C code inside a
14274 function, there are many ways to shoot yourself in the foot doing this,
14275 and it is recommended that you stick to inline assembler.
14278 Use of Labels within Inline Assembler
14281 SDCC allows the use of in-line assembler with a few restrictions regarding
14283 In older versions of the compiler all labels defined within inline assembler
14292 where nnnn is a number less than 100 (which implies a limit of utmost 100
14293 inline assembler labels
14307 \begin_inset LatexCommand \index{\_asm}
14312 \begin_inset LatexCommand \index{\_\_asm}
14342 \begin_inset LatexCommand \index{\_endasm}
14347 \begin_inset LatexCommand \index{\_\_endasm}
14354 Inline assembler code cannot reference any C-Labels, however it can reference
14356 \begin_inset LatexCommand \index{Labels}
14360 defined by the inline assembler, e.g.:
14385 ; some assembler code
14405 /* some more c code */
14407 clabel:\SpecialChar ~
14409 /* inline assembler cannot reference this label */
14421 $0003: ;label (can be referenced by inline assembler only)
14428 \begin_inset LatexCommand \index{\_endasm}
14433 \begin_inset LatexCommand \index{\_\_endasm}
14443 /* some more c code */
14448 In other words inline assembly code can access labels defined in inline
14449 assembly within the scope of the function.
14450 The same goes the other way, i.e.
14451 labels defines in inline assembly can not be accessed by C statements.
14454 Interfacing with Assembler Code
14455 \begin_inset LatexCommand \index{Assembler routines}
14462 Global Registers used for Parameter Passing
14463 \begin_inset LatexCommand \index{Parameter passing}
14470 The compiler always uses the global registers
14473 \begin_inset LatexCommand \index{DPTR, DPH, DPL}
14478 \begin_inset LatexCommand \index{DPTR}
14483 \begin_inset LatexCommand \index{B (mcs51, ds390 register)}
14492 \begin_inset LatexCommand \index{ACC (mcs51, ds390 register)}
14498 to pass the first parameter to a routine.
14499 The second parameter onwards is either allocated on the stack (for reentrant
14510 -stack-auto is used) or in data / xdata memory (depending on the memory
14515 Assembler Routine (non-reentrant)
14518 In the following example
14519 \begin_inset LatexCommand \index{reentrant}
14524 \begin_inset LatexCommand \index{Assembler routines (non-reentrant)}
14528 the function c_func calls an assembler routine asm_func, which takes two
14530 \begin_inset LatexCommand \index{function parameter}
14539 extern int asm_func(unsigned char, unsigned char);
14543 int c_func (unsigned char i, unsigned char j)
14551 return asm_func(i,j);
14565 return c_func(10,9);
14570 The corresponding assembler function is:
14575 .globl _asm_func_PARM_2
14676 \begin_inset LatexCommand \index{DPTR, DPH, DPL}
14693 Note here that the return values
14694 \begin_inset LatexCommand \index{return value}
14698 are placed in 'dpl' - One byte return value, 'dpl' LSB & 'dph' MSB for
14700 'dpl', 'dph' and 'b' for three byte values (generic pointers) and 'dpl','dph','
14701 b' & 'acc' for four byte values.
14704 The parameter naming convention is _<function_name>_PARM_<n>, where n is
14705 the parameter number starting from 1, and counting from the left.
14706 The first parameter is passed in
14707 \begin_inset Quotes eld
14711 \begin_inset Quotes erd
14714 for a one byte parameter,
14715 \begin_inset Quotes eld
14719 \begin_inset Quotes erd
14723 \begin_inset Quotes eld
14727 \begin_inset Quotes erd
14730 for three bytes and
14731 \begin_inset Quotes eld
14735 \begin_inset Quotes erd
14738 for a four bytes parameter.
14739 The variable name for the second parameter will be _<function_name>_PARM_2.
14743 Assemble the assembler routine with the following command:
14750 asx8051 -losg asmfunc.asm
14757 Then compile and link the assembler routine to the C source file with the
14765 sdcc cfunc.c asmfunc.rel
14768 Assembler Routine (reentrant)
14772 \begin_inset LatexCommand \index{reentrant}
14777 \begin_inset LatexCommand \index{Assembler routines (reentrant)}
14781 the second parameter
14782 \begin_inset LatexCommand \index{function parameter}
14786 onwards will be passed on the stack, the parameters are pushed from right
14788 after the call the leftmost parameter will be on the top of the stack.
14789 Here is an example:
14794 extern int asm_func(unsigned char, unsigned char);
14798 int c_func (unsigned char i, unsigned char j) reentrant
14806 return asm_func(i,j);
14820 return c_func(10,9);
14825 The corresponding assembler routine is:
14924 \added_space_bottom bigskip
14925 The compiling and linking procedure remains the same, however note the extra
14926 entry & exit linkage required for the assembler code, _bp is the stack
14927 frame pointer and is used to compute the offset into the stack for parameters
14928 and local variables.
14932 \begin_inset LatexCommand \index{int (16 bit)}
14937 \begin_inset LatexCommand \index{long (32 bit)}
14944 For signed & unsigned int (16 bit) and long (32 bit) variables, division,
14945 multiplication and modulus operations are implemented by support routines.
14946 These support routines are all developed in ANSI-C to facilitate porting
14947 to other MCUs, although some model specific assembler optimizations are
14949 The following files contain the described routines, all of them can be
14950 found in <installdir>/share/sdcc/lib.
14956 \begin_inset Tabular
14957 <lyxtabular version="3" rows="11" columns="2">
14959 <column alignment="left" valignment="top" leftline="true" width="0">
14960 <column alignment="left" valignment="top" leftline="true" rightline="true" width="0">
14961 <row topline="true" bottomline="true">
14962 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
14972 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
14983 <row topline="true">
14984 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
14992 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
14997 16 bit multiplication
15001 <row topline="true">
15002 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15010 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15015 signed 16 bit division (calls _divuint)
15019 <row topline="true">
15020 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15028 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15033 unsigned 16 bit division
15037 <row topline="true">
15038 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15046 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15051 signed 16 bit modulus (calls _moduint)
15055 <row topline="true">
15056 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15064 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15069 unsigned 16 bit modulus
15073 <row topline="true">
15074 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15082 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15087 32 bit multiplication
15091 <row topline="true">
15092 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15100 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15105 signed 32 division (calls _divulong)
15109 <row topline="true">
15110 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15118 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15123 unsigned 32 division
15127 <row topline="true">
15128 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15136 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15141 signed 32 bit modulus (calls _modulong)
15145 <row topline="true" bottomline="true">
15146 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15154 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15159 unsigned 32 bit modulus
15172 Since they are compiled as
15177 \begin_inset LatexCommand \index{reentrant}
15182 \begin_inset LatexCommand \index{interrupt}
15186 service routines should not do any of the above operations.
15187 If this is unavoidable then the above routines will need to be compiled
15201 \begin_inset LatexCommand \index{-\/-stack-auto}
15207 option, after which the source program will have to be compiled with
15220 \begin_inset LatexCommand \index{-\/-int-long-reent}
15227 Notice that you don't have to call these routines directly.
15228 The compiler will use them automatically every time an integer operation
15232 Floating Point Support
15233 \begin_inset LatexCommand \index{Floating point support}
15240 SDCC supports IEEE (single precision 4 bytes) floating point numbers.
15241 The floating point support routines are derived from gcc's floatlib.c and
15242 consist of the following routines:
15250 \begin_inset Tabular
15251 <lyxtabular version="3" rows="17" columns="2">
15253 <column alignment="left" valignment="top" leftline="true" width="0">
15254 <column alignment="left" valignment="top" leftline="true" rightline="true" width="0">
15255 <row topline="true" bottomline="true">
15256 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15273 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15282 <row topline="true">
15283 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15300 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15314 add floating point numbers
15318 <row topline="true">
15319 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15336 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15350 subtract floating point numbers
15354 <row topline="true">
15355 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15372 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15386 divide floating point numbers
15390 <row topline="true">
15391 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15408 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15422 multiply floating point numbers
15426 <row topline="true">
15427 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15444 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15458 convert floating point to unsigned char
15462 <row topline="true">
15463 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15480 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15494 convert floating point to signed char
15498 <row topline="true">
15499 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15516 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15530 convert floating point to unsigned int
15534 <row topline="true">
15535 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15552 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15566 convert floating point to signed int
15570 <row topline="true">
15571 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15597 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15611 convert floating point to unsigned long
15615 <row topline="true">
15616 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15633 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15647 convert floating point to signed long
15651 <row topline="true">
15652 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15669 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15683 convert unsigned char to floating point
15687 <row topline="true">
15688 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15705 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15719 convert char to floating point number
15723 <row topline="true">
15724 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15741 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15755 convert unsigned int to floating point
15759 <row topline="true">
15760 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15777 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15791 convert int to floating point numbers
15795 <row topline="true">
15796 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15813 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15827 convert unsigned long to floating point number
15831 <row topline="true" bottomline="true">
15832 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
15849 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
15863 convert long to floating point number
15875 \added_space_bottom bigskip
15876 These support routines are developed in ANSI-C so there is room for space
15877 and speed improvement
15883 These floating point routines (
15887 sinf(), cosf(), ...) for the mcs51 are implemented in assembler.
15892 Note if all these routines are used simultaneously the data space might
15894 For serious floating point usage the large model might be needed.
15895 Also notice that you don't have to call this routines directly.
15896 The compiler will use them automatically every time a floating point operation
15901 \begin_inset LatexCommand \index{Libraries}
15910 <pending: this is messy and incomplete - a little more information is in
15911 sdcc/doc/libdoc.txt
15916 Compiler support routines (_gptrget, _mulint etc.)
15919 Stdclib functions (puts, printf, strcat etc.)
15920 \layout Subsubsection
15926 \begin_inset LatexCommand \index{<stdio.h>}
15930 As usual on embedded systems you have to provide your own
15933 \begin_inset LatexCommand \index{getchar()}
15942 \begin_inset LatexCommand \index{putchar()}
15949 SDCC does not know whether the system connects to a serial line with or
15950 without handshake, LCD, keyboard or other device.
15964 You'll find examples for serial routines f.e.
15965 in sdcc/device/lib.
15971 \begin_inset LatexCommand \index{printf()}
15981 does not support float (except on ds390).
15982 To enable this recompile it with the option
15995 \begin_inset LatexCommand \index{USE\_FLOATS}
16001 on the command line.
16015 \begin_inset LatexCommand \index{-\/-model-large}
16021 for the mcs51 port, since this uses a lot of memory.
16024 If you're short on memory you might want to use
16027 \begin_inset LatexCommand \index{printf\_small()}
16042 For the mcs51 there additionally are assembly versions
16045 \begin_inset LatexCommand \index{printf\_tiny() (mcs51)}
16051 (subset of printf using less than 270 bytes) and
16054 \begin_inset LatexCommand \index{printf\_fast() (mcs51)}
16063 \begin_inset LatexCommand \index{printf\_fast\_f() (mcs51)}
16069 (floating-point aware version of printf_fast) which should fit the requirements
16070 of many embedded systems (printf_fast() can be customized by unsetting
16075 support long variables and field widths).
16076 \layout Subsubsection
16079 \begin_inset LatexCommand \index{malloc.h}
16086 As of SDCC 2.6.2 you no longer need to call an initialization routine before
16087 using dynamic memory allocation
16088 \begin_inset LatexCommand \index{dynamic memory allocation (malloc)}
16093 \begin_inset LatexCommand \index{heap (malloc)}
16097 space of 1024 bytes is provided for malloc to allocate memory from.
16098 If you need a different heap size you need to recompile _heap.c with the
16099 required size defined in HEAP_SIZE.
16100 It is recommended to make a copy of this file into your project directory
16101 and compile it there with:
16106 sdcc -c _heap.c -D HEAD_SIZE=2048
16110 And then link it with:
16115 sdcc main.rel _heap.rel
16120 Math functions (sinf, powf, sqrtf etc.)
16121 \layout Subsubsection
16126 See definitions in file <math.h>.
16133 \begin_inset LatexCommand \index{Libraries}
16137 included in SDCC should have a license at least as liberal as the GNU Lesser
16138 General Public License
16139 \begin_inset LatexCommand \index{GNU Lesser General Public License, LGPL}
16150 license statements for the libraries are missing.
16151 sdcc/device/lib/ser_ir.c
16155 come with a GPL (as opposed to LGPL) License - this will not be liberal
16156 enough for many embedded programmers.
16159 If you have ported some library or want to share experience about some code
16161 falls into any of these categories Busses (I
16162 \begin_inset Formula $^{\textrm{2}}$
16165 C, CAN, Ethernet, Profibus, Modbus, USB, SPI, JTAG ...), Media (IDE, Memory
16166 cards, eeprom, flash...), En-/Decryption, Remote debugging, Realtime kernel,
16167 Keyboard, LCD, RTC, FPGA, PID then the sdcc-user mailing list
16168 \begin_inset LatexCommand \url{http://sourceforge.net/mail/?group_id=599}
16173 would certainly like to hear about it.
16175 \added_space_bottom bigskip
16176 Programmers coding for embedded systems are not especially famous for being
16177 enthusiastic, so don't expect a big hurray but as the mailing list is searchabl
16178 e these references are very valuable.
16179 Let's help to create a climate where information is shared.
16185 MCS51 Memory Models
16186 \begin_inset LatexCommand \index{Memory model}
16191 \begin_inset LatexCommand \index{MCS51 memory model}
16196 \layout Subsubsection
16198 Small, Medium and Large
16201 SDCC allows three memory models for MCS51 code,
16210 Modules compiled with different memory models should
16214 be combined together or the results would be unpredictable.
16215 The library routines supplied with the compiler are compiled as small,
16217 The compiled library modules are contained in separate directories as small,
16218 medium and large so that you can link to the appropriate set.
16221 When the medium or large model is used all variables declared without a
16222 storage class will be allocated into the external ram, this includes all
16223 parameters and local variables (for non-reentrant
16224 \begin_inset LatexCommand \index{reentrant}
16229 When the small model is used variables without storage class are allocated
16230 in the internal ram.
16233 Judicious usage of the processor specific storage classes
16234 \begin_inset LatexCommand \index{Storage class}
16238 and the 'reentrant' function type will yield much more efficient code,
16239 than using the large model.
16240 Several optimizations are disabled when the program is compiled using the
16241 large model, it is therefore recommended that the small model be used unless
16242 absolutely required.
16243 \layout Subsubsection
16246 \begin_inset LatexCommand \label{sub:External-Stack}
16251 \begin_inset LatexCommand \index{stack}
16256 \begin_inset LatexCommand \index{External stack (mcs51)}
16263 The external stack (-
16274 \begin_inset LatexCommand \index{-\/-xstack}
16278 ) is located in pdata
16279 \begin_inset LatexCommand \index{pdata (mcs51, ds390 storage class)}
16283 memory (usually at the start of the external ram segment) and uses all
16284 unused space in pdata (max.
16296 -xstack option is used to compile the program, the parameters and local
16298 \begin_inset LatexCommand \index{local variables}
16302 of all reentrant functions are allocated in this area.
16303 This option is provided for programs with large stack space requirements.
16304 When used with the -
16315 \begin_inset LatexCommand \index{-\/-stack-auto}
16319 option, all parameters and local variables are allocated on the external
16320 stack (note: support libraries will need to be recompiled with the same
16322 There is a predefined target in the library makefile).
16325 The compiler outputs the higher order address byte of the external ram segment
16327 \begin_inset LatexCommand \index{P2 (mcs51 sfr)}
16332 \begin_inset LatexCommand \ref{sub:MCS51-variants}
16336 ), therefore when using the External Stack option, this port
16340 be used by the application program.
16344 \begin_inset LatexCommand \index{Memory model}
16349 \begin_inset LatexCommand \index{DS390 memory model}
16356 The only model supported is Flat 24
16357 \begin_inset LatexCommand \index{Flat 24 (DS390 memory model)}
16362 This generates code for the 24 bit contiguous addressing mode of the Dallas
16364 In this mode, up to four meg of external RAM or code space can be directly
16366 See the data sheets at www.dalsemi.com for further information on this part.
16370 Note that the compiler does not generate any code to place the processor
16371 into 24 bitmode (although
16375 in the ds390 libraries will do that for you).
16381 \begin_inset LatexCommand \index{Tinibios (DS390)}
16385 , the boot loader or similar code must ensure that the processor is in 24
16386 bit contiguous addressing mode before calling the SDCC startup code.
16404 option, variables will by default be placed into the XDATA segment.
16409 Segments may be placed anywhere in the 4 meg address space using the usual
16421 Note that if any segments are located above 64K, the -r flag must be passed
16422 to the linker to generate the proper segment relocations, and the Intel
16423 HEX output format must be used.
16424 The -r flag can be passed to the linker by using the option
16428 on the SDCC command line.
16429 However, currently the linker can not handle code segments > 64k.
16433 \begin_inset LatexCommand \label{sec:Pragmas}
16438 \begin_inset LatexCommand \index{Pragmas}
16445 SDCC supports the following #pragma directives:
16453 \begin_inset LatexCommand \index{\#pragma save}
16457 - this will save most current options to the save/restore stack.
16458 See #pragma\SpecialChar ~
16467 \begin_inset LatexCommand \index{\#pragma restore}
16471 - will restore saved options from the last save.
16472 saves & restores can be nested.
16473 SDCC uses a save/restore stack: save pushes current options to the stack,
16474 restore pulls current options from the stack.
16475 See #pragma\SpecialChar ~
16486 \begin_inset LatexCommand \index{\#pragma callee\_saves}
16491 \begin_inset LatexCommand \index{function prologue}
16495 function1[,function2[,function3...]] - The compiler by default uses a caller
16496 saves convention for register saving across function calls, however this
16497 can cause unnecessary register pushing & popping
16498 \begin_inset LatexCommand \index{push/pop}
16502 when calling small functions from larger functions.
16503 This option can be used to switch off the register saving convention for
16504 the function names specified.
16505 The compiler will not save registers when calling these functions, extra
16506 code need to be manually inserted at the entry & exit for these functions
16507 to save & restore the registers used by these functions, this can SUBSTANTIALLY
16508 reduce code & improve run time performance of the generated code.
16509 In the future the compiler (with inter procedural analysis) may be able
16510 to determine the appropriate scheme to use for each function call.
16521 -callee-saves command line option is used, the function names specified
16522 in #pragma\SpecialChar ~
16524 \begin_inset LatexCommand \index{\#pragma callee\_saves}
16528 is appended to the list of functions specified in the command line.
16536 \begin_inset LatexCommand \index{\#pragma exclude}
16540 none | {acc[,b[,dpl[,dph]]] - The exclude pragma disables the generation
16541 of pairs of push/pop
16542 \begin_inset LatexCommand \index{push/pop}
16551 \begin_inset LatexCommand \index{interrupt}
16564 The directive should be placed immediately before the ISR function definition
16565 and it affects ALL ISR functions following it.
16566 To enable the normal register saving for ISR functions use #pragma\SpecialChar ~
16567 exclude\SpecialChar ~
16569 \begin_inset LatexCommand \index{\#pragma exclude}
16574 See also the related keyword _naked
16575 \begin_inset LatexCommand \index{\_naked}
16580 \begin_inset LatexCommand \index{\_\_naked}
16592 \begin_inset LatexCommand \index{\#pragma less\_pedantic}
16596 - the compiler will not warn you anymore for obvious mistakes, you'r on
16605 \begin_inset LatexCommand \index{\#pragma disable\_warning}
16609 - the compiler will not warn you anymore about warning number <nnnn>.
16617 \begin_inset LatexCommand \index{\#pragma nogcse}
16621 - will stop global common subexpression elimination.
16629 \begin_inset LatexCommand \index{\#pragma noinduction}
16633 - will stop loop induction optimizations.
16641 \begin_inset LatexCommand \index{\#pragma noinvariant}
16645 - will not do loop invariant optimizations.
16646 For more details see Loop Invariants in section
16647 \begin_inset LatexCommand \ref{sub:Loop-Optimizations}
16659 \begin_inset LatexCommand \index{\#pragma noiv}
16663 - Do not generate interrupt
16664 \begin_inset LatexCommand \index{interrupt}
16669 \begin_inset LatexCommand \index{interrupt vector table}
16673 entries for all ISR functions defined after the pragma.
16674 This is useful in cases where the interrupt vector table must be defined
16675 manually, or when there is a secondary, manually defined interrupt vector
16677 for the autovector feature of the Cypress EZ-USB FX2).
16678 More elegantly this can be achieved by obmitting the optional interrupt
16679 number after the interrupt keyword, see section
16680 \begin_inset LatexCommand \ref{sub:Interrupt-Service-Routines}
16693 \begin_inset LatexCommand \index{\#pragma nojtbound}
16697 - will not generate code for boundary value checking, when switch statements
16698 are turned into jump-tables (dangerous).
16699 For more details see section
16700 \begin_inset LatexCommand \ref{sub:'switch'-Statements}
16712 \begin_inset LatexCommand \index{\#pragma noloopreverse}
16716 - Will not do loop reversal optimization
16724 \begin_inset LatexCommand \index{\#pragma nooverlay}
16728 - the compiler will not overlay the parameters and local variables of a
16737 \begin_inset LatexCommand \index{\#pragma stackauto}
16752 \begin_inset LatexCommand \index{-\/-stack-auto}
16757 \begin_inset LatexCommand \ref{sec:Parameters-and-Local-Variables}
16761 Parameters and Local Variables.
16769 \begin_inset LatexCommand \index{\#pragma opt\_code\_speed}
16773 - The compiler will optimize code generation towards fast code, possibly
16774 at the expense of code size.
16775 Currently this has little effect.
16783 \begin_inset LatexCommand \index{\#pragma opt\_code\_size}
16787 - The compiler will optimize code generation towards compact code, possibly
16788 at the expense of code speed.
16789 Currently this has little effect.
16797 \begin_inset LatexCommand \index{\#pragma opt\_code\_balanced}
16801 - The compiler will attempt to generate code that is both compact and fast,
16802 as long as meeting one goal is not a detriment to the other (this is the
16812 \begin_inset LatexCommand \index{\#pragma std\_sdcc89}
16816 - Generally follow the C89 standard, but allow SDCC features that conflict
16817 with the standard (default).
16825 \begin_inset LatexCommand \index{\#pragma std\_c89}
16829 - Follow the C89 standard and disable SDCC features that conflict with the
16838 \begin_inset LatexCommand \index{\#pragma std\_sdcc99}
16842 - Generally follow the C99 standard, but allow SDCC features that conflict
16843 with the standard (incomplete support).
16851 \begin_inset LatexCommand \index{\#pragma std\_c99}
16855 - Follow the C99 standard and disable SDCC features that conflict with the
16856 standard (incomplete support).
16864 \begin_inset LatexCommand \index{\#pragma codeseg}
16868 - Use this name (max.
16869 8 characters) for the code segment.
16888 \begin_inset LatexCommand \index{\#pragma constseg}
16892 - Use this name (max.
16893 8 characters) for the const segment.
16907 The preprocessor SDCPP
16908 \begin_inset LatexCommand \index{sdcpp (preprocessor)}
16912 supports the following #pragma directives:
16917 pedantic_parse_number
16920 \begin_inset LatexCommand \index{\#pragma pedantic\_parse\_number}
16924 (+ | -) - Pedantic parse numbers so that situations like 0xfe-LO_B(3) are
16925 parsed properly and the macro LO_B(3) gets expanded.
16927 Below is an example on how to use this pragma.
16930 Note: this functionality is not in conformance with standard!
16935 #pragma pedantic_parse_number +
16936 \begin_inset LatexCommand \index{\#pragma pedantic\_parse\_number}
16944 #define LO_B(x) ((x) & 0xff)
16948 unsigned char foo(void)
16955 unsigned char c=0xfe-LO_B(3);
16976 \begin_inset LatexCommand \index{\#pragma preproc\_asm}
16980 (+ | -) - switch _asm _endasm block preprocessing on / off.
16982 You use this prama to define multilines of assembly code.
16983 This will prevent the preprocessor from changing the formating required
16985 Below is an example on how to use this pragma.
16990 #pragma preproc_asm -
16991 \begin_inset LatexCommand \index{\#pragma preproc\_asm}
16997 #define MYDELAY _asm
17002 nop ;my assembly comment...
17016 #pragma preproc_asm +
17051 \begin_inset LatexCommand \index{\#pragma sdcc\_hash}
17055 (+ | -) - Allow "naked" hash in macro definition, for example:
17059 #define DIR_LO(x) #(x & 0xff)
17064 Below is an example on how to use this pragma.
17069 #pragma preproc_asm +
17071 #pragma sdcc_hash +
17072 \begin_inset LatexCommand \index{\#pragma sdcc\_hash}
17087 mov R6_B3, #(x & 0xff)
17094 mov R7_B3, #((x >> 8) & 0xff)
17120 The pragma's are intended to be used to turn-on or off certain optimizations
17121 which might cause the compiler to generate extra stack / data space to
17122 store compiler generated temporary variables.
17123 This usually happens in large functions.
17124 Pragma directives should be used as shown in the following example, they
17125 are used to control options & optimizations for a given function; pragmas
17126 should be placed before and/or after a function, placing pragma's inside
17127 a function body could have unpredictable results.
17133 \begin_inset LatexCommand \index{\#pragma save}
17144 /* save the current settings */
17147 \begin_inset LatexCommand \index{\#pragma nogcse}
17156 /* turnoff global subexpression elimination */
17158 #pragma noinduction
17159 \begin_inset LatexCommand \index{\#pragma noinduction}
17163 /* turn off induction optimizations */
17186 \begin_inset LatexCommand \index{\#pragma restore}
17190 /* turn the optimizations back on */
17193 The compiler will generate a warning message when extra space is allocated.
17194 It is strongly recommended that the save and restore pragma's be used when
17195 changing options for a function.
17204 Defines Created by the Compiler
17207 The compiler creates the following #defines
17208 \begin_inset LatexCommand \index{\#defines}
17213 \begin_inset LatexCommand \index{Defines created by the compiler}
17223 \begin_inset Tabular
17224 <lyxtabular version="3" rows="11" columns="2">
17226 <column alignment="left" valignment="top" leftline="true" width="3in">
17227 <column alignment="left" valignment="top" leftline="true" rightline="true" width="3in">
17228 <row topline="true" bottomline="true">
17229 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17239 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17250 <row topline="true">
17251 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17257 \begin_inset LatexCommand \index{SDCC}
17264 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17270 Since version 2.5.6 the version number as an int (ex.
17275 <row topline="true">
17276 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17282 \begin_inset LatexCommand \index{SDCC\_mcs51}
17287 \begin_inset LatexCommand \index{SDCC\_ds390}
17292 \begin_inset LatexCommand \index{SDCC\_z80}
17299 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17304 depending on the model used (e.g.: -mds390)
17308 <row topline="true">
17309 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17315 \begin_inset LatexCommand \index{\_\_mcs51}
17320 \begin_inset LatexCommand \index{\_\_ds390}
17325 \begin_inset LatexCommand \index{\_\_hc08}
17330 \begin_inset LatexCommand \index{\_\_z80}
17337 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17342 depending on the model used (e.g.
17347 <row topline="true">
17348 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17354 \begin_inset LatexCommand \index{SDCC\_STACK\_AUTO}
17361 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17384 <row topline="true">
17385 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17391 \begin_inset LatexCommand \index{SDCC\_MODEL\_SMALL}
17398 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17421 <row topline="true">
17422 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17428 \begin_inset LatexCommand \index{SDCC\_MODEL\_MEDIUM}
17435 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17458 <row topline="true">
17459 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17465 \begin_inset LatexCommand \index{SDCC\_MODEL\_LARGE}
17472 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17495 <row topline="true">
17496 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17502 \begin_inset LatexCommand \index{SDCC\_USE\_XSTACK}
17509 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17532 <row topline="true">
17533 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17539 \begin_inset LatexCommand \index{SDCC\_STACK\_TENBIT}
17546 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17559 <row topline="true" bottomline="true">
17560 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
17566 \begin_inset LatexCommand \index{SDCC\_MODEL\_FLAT24}
17573 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
17593 Notes on supported Processors
17597 \begin_inset LatexCommand \label{sub:MCS51-variants}
17602 \begin_inset LatexCommand \index{MCS51 variants}
17609 MCS51 processors are available from many vendors and come in many different
17611 While they might differ considerably in respect to Special Function Registers
17612 the core MCS51 is usually not modified or is kept compatible.
17616 pdata access by SFR
17619 With the upcome of devices with internal xdata and flash memory devices
17621 \begin_inset LatexCommand \index{P2 (mcs51 sfr)}
17625 as dedicated I/O port is becoming more popular.
17626 Switching the high byte for pdata
17627 \begin_inset LatexCommand \index{pdata (mcs51, ds390 storage class)}
17631 access which was formerly done by port P2 is then achieved by a Special
17633 \begin_inset LatexCommand \index{sfr}
17638 In well-established MCS51 tradition the address of this
17642 is where the chip designers decided to put it.
17643 Needless to say that they didn't agree on a common name either.
17644 So that the startup code can correctly initialize xdata variables, you
17645 should define an sfr with the name _XPAGE
17648 \begin_inset LatexCommand \index{\_XPAGE (mcs51)}
17654 at the appropriate location if the default, port P2, is not used for this.
17660 __sfr __at (0x92) _XPAGE; /* Cypress EZ-USB family */
17665 __sfr __at (0xaf) _XPAGE; /* some Silicon Labs (Cygnal) chips */
17670 __sfr __at (0xaa) _XPAGE; /* some Silicon Labs (Cygnal) chips */
17673 For more exotic implementations further customizations may be needed.
17675 \begin_inset LatexCommand \ref{sub:Startup-Code}
17679 for other possibilities.
17682 Other Features available by SFR
17684 \added_space_bottom bigskip
17685 Some MCS51 variants offer features like Double DPTR
17686 \begin_inset LatexCommand \index{DPTR}
17690 , multiple DPTR, decrementing DPTR, 16x16 Multiply.
17691 These are currently not used for the MCS51 port.
17692 If you absolutely need them you can fall back to inline assembly or submit
17698 \added_space_bottom bigskip
17700 \begin_inset LatexCommand \index{DS80C400}
17705 \begin_inset LatexCommand \index{DS400}
17709 microcontroller has a rich set of peripherals.
17710 In its built-in ROM library it includes functions to access some of the
17711 features, among them is a TCP stack with IP4 and IP6 support.
17712 Library headers (currently in beta status) and other files are provided
17716 \begin_inset LatexCommand \url{ftp://ftp.dalsemi.com/pub/tini/ds80c400/c_libraries/sdcc/index.html}
17724 The Z80 and gbz80 port
17727 SDCC can target both the Zilog Z80
17728 \begin_inset LatexCommand \index{Z80}
17732 and the Nintendo Gameboy's Z80-like gbz80
17733 \begin_inset LatexCommand \index{gbz80 (GameBoy Z80)}
17738 The Z80 port is passed through the same
17741 \begin_inset LatexCommand \index{Regression test}
17748 \begin_inset LatexCommand \ref{sec:Quality-control}
17752 ) as the MCS51 and DS390 ports, so floating point support, support for long
17753 variables and bitfield support is fine.
17754 See mailing lists and forums about interrupt routines.
17756 \added_space_bottom bigskip
17757 As always, the code is the authoritative reference - see z80/ralloc.c and
17760 \begin_inset LatexCommand \index{Z80!stack}
17764 frame is similar to that generated by the IAR Z80 compiler.
17765 IX is used as the base pointer, HL and IY are used as a temporary registers,
17766 and BC and DE are available for holding variables.
17768 \begin_inset LatexCommand \index{Z80!return value}
17772 for the Z80 port are stored in L (one byte), HL (two bytes), or DEHL (four
17774 The gbz80 port use the same set of registers for the return values, but
17775 in a different order of significance: E (one byte), DE (two bytes), or
17782 The port to the Freescale/Motorola HC08
17783 \begin_inset LatexCommand \index{HC08}
17787 family has been added in October 2003, and is still undergoing some basic
17789 The code generator is complete, but the register allocation is still quite
17791 Some of the SDCC's standard C library functions have embedded non-HC08
17792 inline assembly and so are not yet usable.
17794 \added_space_bottom bigskip
17795 The HC08 port passes the regression test suite (see section
17796 \begin_inset LatexCommand \ref{sec:Quality-control}
17807 \begin_inset LatexCommand \index{PIC14}
17811 port still requires a major effort from the development community.
17812 However it can work for simple code.
17813 It passes its (smaller set of) regression tests
17814 \begin_inset LatexCommand \index{Regression test (PIC14)}
17820 sdcc/src/regression
17825 C code and 14bit PIC code page
17826 \begin_inset LatexCommand \index{code page (pic14)}
17831 \begin_inset LatexCommand \index{RAM bank (pic14)}
17838 The linker organizes allocation for the code page and RAM banks.
17839 It does not have intimate knowledge of the code flow.
17840 It will put all the code section of a single asm file into a single code
17842 In order to make use of multiple code pages, separate asm files must be
17844 The compiler treats all functions of a single C file as being in the same
17845 code page unless it is non static.
17846 The compiler treats all local variables of a single C file as being in
17847 the same RAM bank unless it is an extern.
17851 To get the best follow these guide lines:
17854 make local functions static, as non static functions require code page selection
17858 Make local variables static as extern variables require RAM bank selection
17862 For devices that have multiple code pages it is more efficient to use the
17863 same number of files as pages, i.e.
17864 for the 16F877 use 4 separate files and i.e.
17865 for the 16F874 use 2 separate files.
17866 This way the linker can put the code for each file into different code
17867 pages and the compiler can allocate reusable variables more efficiently
17868 and there's less page selection overhead.
17869 And as for any 8 bit micro (especially for PIC 14 as they have a very simple
17870 instruction set) use 'unsigned char' whereever possible instead of 'int'.
17873 Creating a device include file
17876 For generating a device include file
17877 \begin_inset LatexCommand \index{PIC14!Header files}
17881 use the support perl script inc2h.pl kept in directory support/script.
17887 For the interrupt function, use the keyword 'interrupt'
17888 \begin_inset LatexCommand \index{PIC14!interrupt}
17892 with level number of 0 (PIC14 only has 1 interrupt so this number is only
17893 there to avoid a syntax error - it ought to be fixed).
17899 void Intr(void) interrupt 0
17905 T0IF = 0; /* Clear timer interrupt */
17910 Linking and assembling
17913 For assembling you can use either GPUTILS'
17914 \begin_inset LatexCommand \index{gputils (pic tools)}
17918 gpasm.exe or MPLAB's mpasmwin.exe.
17919 GPUTILS is available from
17920 \begin_inset LatexCommand \url{http://sourceforge.net/projects/gputils}
17925 For linking you can use either GPUTIL's gplink or MPLAB's mplink.exe.
17926 If you use MPLAB and an interrupt function then the linker script file
17927 vectors section will need to be enlarged to link with mplink.
17950 sdcc -S -V -mpic14 -p16F877 $<
17964 $(PRJ).hex: $(OBJS)
17974 gplink -m -s $(PRJ).lkr -o $(PRJ).hex $(OBJS) libsdcc.lib
17996 sdcc -S -V -mpic14 -p16F877 $<
18006 mpasmwin /q /o $*.asm
18010 $(PRJ).hex: $(OBJS)
18020 mplink /v $(PRJ).lkr /m $(PRJ).map /o $(PRJ).hex $(OBJS) libsdcc.lib
18023 Please note that indentations within a
18027 have to be done with a tabulator character.
18030 Command-line options
18033 Besides the switches common to all SDCC backends, the PIC14 port accepts
18034 the following options (for an updated list see sdcc -
18046 \labelwidthstring 00.00.0000
18059 \begin_inset LatexCommand \index{PIC14!Options!-\/-debug-extra}
18063 emit debug info in assembly output
18065 \labelwidthstring 00.00.0000
18078 \begin_inset LatexCommand \index{PIC14!Options!-\/-no-pcode-opt}
18082 disable (slightly faulty) optimization on pCode
18086 \layout Subsubsection
18088 error: missing definition for symbol
18089 \begin_inset Quotes sld
18093 \begin_inset Quotes srd
18099 The PIC14 port uses library routines to provide more complex operations
18100 like multiplication, division/modulus and (generic) pointer dereferencing.
18101 In order to add these routines to your project, you must link with PIC14's
18107 For single source file projects this is done automatically, more complex
18112 to the linker's arguments.
18113 Make sure you also add an include path for the library (using the -I switch
18115 \layout Subsubsection
18117 Processor mismatch in file
18118 \begin_inset Quotes sld
18122 \begin_inset Quotes srd
18128 This warning can usually be ignored due to the very good compatibility amongst
18130 \begin_inset LatexCommand \index{PIC14}
18137 You might also consider recompiling the library for your specific device
18138 by changing the ARCH=p16f877 (default target) entry in
18140 device/lib/pic/Makefile.in
18144 device/lib/pic/Makefile
18146 to reflect your device.
18147 This might even improve performance for smaller devices as unneccesary
18148 BANKSELs migth be removed.
18152 \layout Subsubsection
18157 Currently, data can only be initialized if it resides in the source file
18163 Data in other source files will silently
18171 \begin_inset Marginal
18186 \begin_inset LatexCommand \index{PIC16}
18194 \begin_inset LatexCommand \index{PIC16}
18198 port is the portion of SDCC that is responsible to produce code for the
18200 \begin_inset LatexCommand \index{Microchip}
18204 (TM) microcontrollers with 16 bit core.
18205 Currently this family of microcontrollers contains the PIC18Fxxx and PIC18Fxxxx.
18206 Currently supported devices are:
18210 \begin_inset Tabular
18211 <lyxtabular version="3" rows="4" columns="6">
18213 <column alignment="center" valignment="top" leftline="true" width="0">
18214 <column alignment="center" valignment="top" leftline="true" width="0">
18215 <column alignment="center" valignment="top" leftline="true" width="0">
18216 <column alignment="center" valignment="top" leftline="true" width="0">
18217 <column alignment="center" valignment="top" leftline="true" width="0">
18218 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
18219 <row topline="true">
18220 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18228 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18236 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18244 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18252 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18260 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18269 <row topline="true">
18270 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18278 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18286 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18294 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18302 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18310 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18319 <row topline="true">
18320 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18328 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18336 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18344 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18352 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18360 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18369 <row topline="true" bottomline="true">
18370 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18378 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18386 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18394 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18401 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18408 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18426 PIC16 port supports the standard command line arguments as supposed, with
18427 the exception of certain cases that will be mentioned in the following
18430 \labelwidthstring 00.00.0000
18443 \begin_inset LatexCommand \index{PIC16!Options!-\/-callee-saves}
18459 \labelwidthstring 00.00.0000
18472 \begin_inset LatexCommand \index{PIC16!Options!-\/-all-callee-saves}
18476 All function arguments are passed on stack by default.
18479 There is no need to specify this in the command line.
18481 \labelwidthstring 00.00.0000
18493 -fommit-frame-pointer
18494 \begin_inset LatexCommand \index{PIC16!Options!-\/-fommit-frame-pointer}
18498 Frame pointer will be omitted when the function uses no local variables.
18501 Port Specific Options
18502 \begin_inset LatexCommand \index{Options PIC16}
18509 The port specific options appear after the global options in the sdcc --help
18511 \layout Subsubsection
18516 General options enable certain port features and optimizations.
18518 \labelwidthstring 00.00.0000
18530 -stack-model=[model] Used in conjuction with the command above.
18531 Defines the stack model to be used, valid stack models are :
18534 \labelwidthstring 00.00.0000
18540 Selects small stack model.
18541 8 bit stack and frame pointers.
18542 Supports 256 bytes stack size.
18544 \labelwidthstring 00.00.0000
18550 Selects large stack model.
18551 16 bit stack and frame pointers.
18552 Supports 65536 bytes stack size.
18555 \labelwidthstring 00.00.0000
18567 -preplace-udata-with=[kword] Replaces the default udata keyword for allocating
18568 unitialized data variables with [kword].
18569 Valid keywords are: "udata_acs", "udata_shr", "udata_ovr".
18571 \labelwidthstring 00.00.0000
18583 -ivt-loc <nnnn> positions the Interrupt Vector Table at location <nnnn>.
18584 Useful for bootloaders.
18586 \labelwidthstring 00.00.0000
18598 -asm= sets the full path and name of an external assembler to call.
18600 \labelwidthstring 00.00.0000
18612 -link= sets the full path and name of an external linker to call.
18614 \labelwidthstring 00.00.0000
18627 \begin_inset LatexCommand \index{PIC16!MPLAB}
18631 compatibility option.
18632 Currently only suppresses special gpasm directives.
18633 \layout Subsubsection
18635 Optimization Options
18637 \labelwidthstring 00.00.0000
18649 -optimize-goto Try to use (conditional) BRA instead of GOTO
18651 \labelwidthstring 00.00.0000
18663 -optimize-cmp Try to optimize some compares.
18665 \labelwidthstring 00.00.0000
18677 -optimize-df Analyze the dataflow of the generated code and improve it.
18679 \labelwidthstring 00.00.0000
18691 -obanksel=nn Set optimization level for inserting BANKSELs.
18696 \labelwidthstring 00.00.0000
18700 \labelwidthstring 00.00.0000
18702 1 checks previous used register and if it is the same then does not emit
18703 BANKSEL, accounts only for labels.
18705 \labelwidthstring 00.00.0000
18707 2 tries to check the location of (even different) symbols and removes BANKSELs
18708 if they are in the same bank.
18713 Important: There might be problems if the linker script has data sections
18714 across bank borders!
18716 \layout Subsubsection
18720 \labelwidthstring 00.00.0000
18732 -nodefaultlibs do not link default libraries when linking
18734 \labelwidthstring 00.00.0000
18746 -no-crt Don't link the default run-time modules
18748 \labelwidthstring 00.00.0000
18760 -use-crt= Use a custom run-time module instead of the defaults.
18761 \layout Subsubsection
18766 Debugging options enable extra debugging information in the output files.
18768 \labelwidthstring 00.00.0000
18780 -debug-xtra Similar to -
18791 \begin_inset LatexCommand \index{-\/-debug}
18795 , but dumps more information.
18797 \labelwidthstring 00.00.0000
18809 -debug-ralloc Force register allocator to dump <source>.d file with debugging
18811 <source> is the name of the file compiled.
18813 \labelwidthstring 00.00.0000
18825 -pcode-verbose Enable pcode debugging information in translation.
18827 \labelwidthstring 00.00.0000
18839 -denable-peeps Force the usage of peepholes.
18842 \labelwidthstring 00.00.0000
18854 -gstack Trace push/pops for stack pointer overflow
18856 \labelwidthstring 00.00.0000
18868 -call-tree dump call tree in .calltree file
18871 Enviromental Variables
18874 There is a number of enviromental variables that can be used when running
18875 SDCC to enable certain optimizations or force a specific program behaviour.
18876 these variables are primarily for debugging purposes so they can be enabled/dis
18880 Currently there is only two such variables available:
18882 \labelwidthstring 00.00.0000
18884 OPTIMIZE_BITFIELD_POINTER_GET when this variable exists reading of structure
18885 bitfields is optimized by directly loading FSR0 with the address of the
18886 bitfield structure.
18887 Normally SDCC will cast the bitfield structure to a bitfield pointer and
18889 This step saves data ram and code space for functions that perform heavy
18892 80 bytes of code space are saved when compiling malloc.c with this option).
18895 \labelwidthstring 00.00.0000
18897 NO_REG_OPT do not perform pCode registers optimization.
18898 This should be used for debugging purposes.
18899 In some where bugs in the pcode optimizer are found, users can benefit
18900 from temporarily disabling the optimizer until the bug is fixed.
18903 Preprocessor Macros
18907 \begin_inset LatexCommand \index{PIC16}
18911 port defines the following preprocessor macros while translating a source.
18915 \begin_inset Tabular
18916 <lyxtabular version="3" rows="6" columns="2">
18918 <column alignment="center" valignment="top" leftline="true" width="0">
18919 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
18920 <row topline="true" bottomline="true">
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">
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" rightline="true" usebox="none">
18952 Port identification
18956 <row topline="true">
18957 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18975 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18980 Port identification (same as above)
18984 <row topline="true">
18985 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
18993 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
18998 MCU Identification.
19003 is the microcontrol identification number, i.e.
19008 <row topline="true">
19009 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19027 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19032 MCU Identification (same as above)
19036 <row topline="true" bottomline="true">
19037 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19045 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19050 nnn = SMALL or LARGE respectively according to the stack model used
19061 In addition the following macros are defined when calling assembler:
19065 \begin_inset Tabular
19066 <lyxtabular version="3" rows="4" columns="2">
19068 <column alignment="center" valignment="top" leftline="true" width="0">
19069 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
19070 <row topline="true" bottomline="true">
19071 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19079 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19088 <row topline="true">
19089 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19097 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19102 MCU Identification.
19107 is the microcontrol identification number, i.e.
19112 <row topline="true">
19113 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19121 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19126 nnn = SMALL or LARGE respectively according to the memory model used for
19131 <row topline="true" bottomline="true">
19132 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19140 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19145 nnn = SMALL or LARGE respectively according to the stack model used
19160 \begin_inset LatexCommand \index{PIC16}
19164 port uses the following directories for searching header files and libraries.
19168 \begin_inset Tabular
19169 <lyxtabular version="3" rows="3" columns="4">
19171 <column alignment="center" valignment="top" leftline="true" width="0">
19172 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
19173 <column alignment="center" valignment="top" width="0">
19174 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
19175 <row topline="true" bottomline="true">
19176 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19184 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19192 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19200 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19209 <row topline="true">
19210 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19215 PREFIX/sdcc/include/pic16
19218 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19223 PIC16 specific headers
19226 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19234 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19243 <row topline="true" bottomline="true">
19244 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19249 PREFIX/sdcc/lib/pic16
19252 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19257 PIC16 specific libraries
19260 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19268 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19285 \begin_inset LatexCommand \label{sub:PIC16_Pragmas}
19293 \begin_inset LatexCommand \index{PIC16}
19297 port currently supports the following pragmas:
19299 \labelwidthstring 00.00.0000
19302 \begin_inset LatexCommand \index{PIC16!Pragmas!\#pragma stack}
19307 \begin_inset LatexCommand \index{PIC16!stack}
19311 forces the code generator to initialize the stack & frame pointers at a
19313 This is an adhoc solution for cases where no STACK directive is available
19314 in the linker script or gplink is not instructed to create a stack section.
19316 The stack pragma should be used only once in a project.
19317 Multiple pragmas may result in indeterminate behaviour of the program.
19323 The old format (ie.
19324 #pragma stack 0x5ff) is deprecated and will cause the stack pointer to
19325 cross page boundaries (or even exceed the available data RAM) and crash
19327 Make sure that stack does not cross page boundaries when using the SMALL
19333 The format is as follows:
19336 #pragma stack bottom_address [stack_size]
19343 is the lower bound of the stack section.
19344 The stack pointer initially will point at address (bottom_address+stack_size-1).
19352 /* initializes stack of 100 bytes at RAM address 0x200 */
19355 #pragma stack 0x200 100
19358 If the stack_size field is omitted then a stack is created with the default
19360 This size might be enough for most programs, but its not enough for operations
19361 with deep function nesting or excessive stack usage.
19363 \labelwidthstring 00.00.0000
19366 \begin_inset LatexCommand \index{PIC16!Pragmas!\#pragma code}
19370 place a function symbol at static FLASH address
19378 /* place function test_func at 0x4000 */
19381 #pragma code test_func 0x4000
19385 \labelwidthstring 00.00.0000
19387 library instructs the linker to use a library module.
19392 #pragma library module_name
19399 can be any library or object file (including its path).
19400 Note that there are four reserved keywords which have special meaning.
19405 \begin_inset Tabular
19406 <lyxtabular version="3" rows="6" columns="3">
19408 <column alignment="center" valignment="top" leftline="true" width="0">
19409 <column alignment="block" valignment="top" leftline="true" width="20page%">
19410 <column alignment="left" valignment="top" leftline="true" rightline="true" width="0">
19411 <row topline="true" bottomline="true">
19412 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19420 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19428 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19437 <row topline="true">
19438 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19448 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19453 ignore all library pragmas
19456 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19467 <row topline="true">
19468 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19478 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19486 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19499 <row topline="true">
19500 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19510 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19515 link the Math libarary
19518 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19531 <row topline="true">
19532 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19542 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19547 link the I/O library
19550 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19563 <row topline="true" bottomline="true">
19564 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19574 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19579 link the debug library
19582 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19601 * is the device number, i.e.
19602 452 for PIC18F452 MCU.
19605 This feature allows for linking with specific libraries withoug having to
19606 explicit name them in the command line.
19611 keyword will reject all modules specified by the library pragma.
19613 \labelwidthstring 00.00.0000
19615 udata pragma udata instructs the compiler to emit code so that linker will
19616 place a variable at a specific memory bank
19624 /* places variable foo at bank2 */
19627 #pragma udata bank2 foo
19633 In order for this pragma to work extra SECTION directives should be added
19634 in the .lkr script.
19635 In the following example a sample .lkr file is shown:
19640 // Sample linker script for the PIC18F452 processor
19646 CODEPAGE NAME=vectors START=0x0 END=0x29 PROTECTED
19649 CODEPAGE NAME=page START=0x2A END=0x7FFF
19652 CODEPAGE NAME=idlocs START=0x200000 END=0x200007 PROTECTED
19655 CODEPAGE NAME=config START=0x300000 END=0x30000D PROTECTED
19658 CODEPAGE NAME=devid START=0x3FFFFE END=0x3FFFFF PROTECTED
19661 CODEPAGE NAME=eedata START=0xF00000 END=0xF000FF PROTECTED
19664 ACCESSBANK NAME=accessram START=0x0 END=0x7F
19669 DATABANK NAME=gpr0 START=0x80 END=0xFF
19672 DATABANK NAME=gpr1 START=0x100 END=0x1FF
19675 DATABANK NAME=gpr2 START=0x200 END=0x2FF
19678 DATABANK NAME=gpr3 START=0x300 END=0x3FF
19681 DATABANK NAME=gpr4 START=0x400 END=0x4FF
19684 DATABANK NAME=gpr5 START=0x500 END=0x5FF
19687 ACCESSBANK NAME=accesssfr START=0xF80 END=0xFFF PROTECTED
19692 SECTION NAME=CONFIG ROM=config
19697 SECTION NAME=bank0 RAM=gpr0 # these SECTION directives
19700 SECTION NAME=bank1 RAM=gpr1 # should be added to link
19703 SECTION NAME=bank2 RAM=gpr2 # section name 'bank?' with
19706 SECTION NAME=bank3 RAM=gpr3 # a specific DATABANK name
19709 SECTION NAME=bank4 RAM=gpr4
19712 SECTION NAME=bank5 RAM=gpr5
19715 The linker will recognise the section name set in the pragma statement and
19716 will position the variable at the memory bank set with the RAM field at
19717 the SECTION line in the linker script file.
19721 \begin_inset LatexCommand \label{sub:PIC16_Header-Files}
19728 There is one main header file
19729 \begin_inset LatexCommand \index{PIC16!Header files}
19733 that can be included to the source files using the pic16
19734 \begin_inset LatexCommand \index{PIC16}
19744 This header file contains the definitions for the processor special registers,
19745 so it is necessary if the source accesses them.
19746 It can be included by adding the following line in the beginning of the
19750 #include <pic18fregs.h>
19753 The specific microcontroller is selected within the pic18fregs.h automatically,
19754 so the same source can be used with a variety of devices.
19761 \begin_inset LatexCommand \index{PIC16!Libraries}
19766 \begin_inset LatexCommand \index{PIC16}
19770 port depends on are the microcontroller device libraries which contain
19771 the symbol definitions for the microcontroller special function registers.
19772 These libraries have the format pic18fxxxx.lib, where
19776 is the microcontroller identification number.
19777 The specific library is selected automatically by the compiler at link
19778 stage according to the selected device.
19781 Libraries are created with gplib which is part of the gputils package
19782 \begin_inset LatexCommand \url{http://sourceforge.net/projects/gputils}
19787 \layout Subsubsection*
19789 Building the libraries
19792 Before using SDCC/pic16 there are some libraries that need to be compiled.
19793 This process is not done automatically by SDCC since not all users use
19794 SDCC for pic16 projects.
19795 So each user should compile the libraries separately.
19798 The steps to compile the pic16 libraries under Linux are:
19801 cd device/lib/pic16
19816 su -c 'make install' # install the libraries, you need the root password
19819 If you need to install the headers too, do:
19825 su -c 'make install' # install the headers, you need the root password
19828 There exist a special target to build the I/O libraries.
19829 This target is not automatically build because it will build the I/O library
19835 This way building will take quite a lot of time.
19836 Users are advised to edit the
19838 device/lib/pic16/pics.build
19840 file and then execute:
19849 The following memory models are supported by the PIC16 port:
19858 Memory model affects the default size of pointers within the source.
19859 The sizes are shown in the next table:
19863 \begin_inset Tabular
19864 <lyxtabular version="3" rows="3" columns="3">
19866 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
19867 <column alignment="center" valignment="top" leftline="true" width="0">
19868 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
19869 <row topline="true" bottomline="true">
19870 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19875 Pointer sizes according to memory model
19878 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19886 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19895 <row topline="true" bottomline="true">
19896 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19904 <cell multicolumn="1" alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19912 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19921 <row topline="true" bottomline="true">
19922 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
19930 <cell multicolumn="1" alignment="center" valignment="top" topline="true" bottomline="true" leftline="true" usebox="none">
19938 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
19954 It is advisable that all sources within a project are compiled with the
19956 If one wants to override the default memory model, this can be done by
19957 declaring a pointer as
19966 Far selects large memory model's pointers, while near selects small memory
19970 The standard device libraries (see
19971 \begin_inset LatexCommand \ref{sub:PIC16_Header-Files}
19975 ) contain no reference to pointers, so they can be used with both memory
19983 \begin_inset LatexCommand \index{PIC16!stack}
19987 implementation for the PIC16 port uses two indirect registers, FSR1 and
19990 \labelwidthstring 00.00.0000
19992 FSR1 is assigned as stack pointer
19994 \labelwidthstring 00.00.0000
19996 FSR2 is assigned as frame pointer
19999 The following stack models are supported by the PIC16 port
20020 model means that only the FSRxL byte is used to access stack and frame,
20027 uses both FSRxL and FSRxH registers.
20028 The following table shows the stack/frame pointers sizes according to stack
20029 model and the maximum space they can address:
20033 \begin_inset Tabular
20034 <lyxtabular version="3" rows="3" columns="3">
20036 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
20037 <column alignment="center" valignment="top" leftline="true" width="0">
20038 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
20039 <row topline="true" bottomline="true">
20040 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20045 Stack & Frame pointer sizes according to stack model
20048 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20056 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20065 <row topline="true">
20066 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20074 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20082 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20091 <row topline="true" bottomline="true">
20092 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20100 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20108 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20128 stack model is currently not working properly throughout the code generator.
20129 So its use is not advised.
20130 Also there are some other points that need special care:
20135 Do not create stack sections with size more than one physical bank (that
20139 Stack sections should no cross physical bank limits (i.e.
20140 #pragma stack 0x50 0x100)
20143 These limitations are caused by the fact that only FSRxL is modified when
20144 using SMALL stack model, so no more than 256 bytes of stack can be used.
20145 This problem will disappear after LARGE model is fully implemented.
20151 In addition to the standard SDCC function keywords, PIC16
20152 \begin_inset LatexCommand \index{PIC16}
20156 port makes available two more:
20158 \labelwidthstring 00.00.0000
20161 \begin_inset LatexCommand \index{PIC16!wparam}
20165 Use the WREG to pass one byte of the first function argument.
20166 This improves speed but you may not use this for functions with arguments
20167 that are called via function pointers, otherwise the first byte of the
20168 first parameter will get lost.
20172 void func_wparam(int a) wparam
20178 /* WREG hold the lower part of a */
20181 /* the high part of a is stored in FSR2+2 (or +3 for large stack model)
20190 \labelwidthstring 00.00.0000
20193 \begin_inset LatexCommand \index{PIC16!shadowregs}
20197 When entering/exiting an ISR, it is possible to take advantage of the PIC18F
20198 hardware shadow registers which hold the values of WREG, STATUS and BSR
20200 This can be done by adding the keyword
20208 keyword in the function's header.
20211 void isr_shadow(void) shadowregs interrupt 1
20227 instructs the code generator not to store/restore WREG, STATUS, BSR when
20228 entering/exiting the ISR.
20231 Function return values
20234 Return values from functions are placed to the appropriate registers following
20235 a modified Microchip policy optimized for SDCC.
20236 The following table shows these registers:
20240 \begin_inset Tabular
20241 <lyxtabular version="3" rows="6" columns="2">
20243 <column alignment="center" valignment="top" leftline="true" width="0">
20244 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
20245 <row topline="true" bottomline="true">
20246 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20254 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20259 destination register
20263 <row topline="true">
20264 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20272 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20281 <row topline="true">
20282 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20290 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20299 <row topline="true">
20300 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20308 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20317 <row topline="true">
20318 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20326 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20331 FSR0L:PRODH:PRODL:WREG
20335 <row topline="true" bottomline="true">
20336 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20344 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20349 on stack, FSR0 points to the beginning
20364 \begin_inset LatexCommand \index{PIC16!interrupt}
20368 service routine (ISR) is declared using the
20375 void isr(void) interrupt
20393 is the interrupt number, which for PIC18F devices can be:
20397 \begin_inset Tabular
20398 <lyxtabular version="3" rows="4" columns="3">
20400 <column alignment="center" valignment="top" leftline="true" width="0">
20401 <column alignment="center" valignment="top" leftline="true" width="0">
20402 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
20403 <row topline="true" bottomline="true">
20404 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20414 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20422 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20427 Interrupt Vector Address
20431 <row topline="true">
20432 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20440 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20448 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20457 <row topline="true">
20458 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20475 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20489 HIGH priority interrupts
20492 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20501 <row topline="true" bottomline="true">
20502 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20510 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20515 LOW priority interrupts
20518 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20534 When generating assembly code for ISR the code generator places a
20540 Interrupt Vector Address
20542 which points at the genetated ISR.
20543 This single GOTO instruction is part of an automatically generated
20545 interrupt entry point
20548 The actuall ISR code is placed as normally would in the code space.
20549 Upon interrupt request, the GOTO instruction is executed which jumps to
20551 When declaring interrupt functions as _naked this GOTO instruction is
20556 The whole interrupt functions is therefore placed at the Interrupt Vector
20557 Address of the specific interrupt.
20558 This is not a problem for the LOW priority interrupts, but it is a problem
20559 for the RESET and the HIGH priority interrupts because code may be written
20560 at the next interrupt´s vector address and cause undeterminate program
20561 behaviour if that interrupt is raised.
20567 This is not a problem when
20570 this is a HIGH interrupt ISR and LOW interrupts are
20577 when the ISR is small enough not to reach the next interrupt´s vector address.
20587 is possible to be omitted.
20588 This way a function is generated similar to an ISR, but it is not assigned
20592 When entering an interrupt, currently the PIC16
20593 \begin_inset LatexCommand \index{PIC16}
20597 port automatically saves the following registers:
20609 PROD (PRODL and PRODH)
20612 FSR0 (FSR0L and FSR0H)
20615 These registers are restored upon return from the interrupt routine.
20621 NOTE that when the _naked attribute is specified for an interrupt routine,
20622 then NO registers are stored or restored.
20631 Generic pointers are implemented in PIC16 port as 3-byte (24-bit) types.
20632 There are 3 types of generic pointers currently implemented data, code
20633 and eeprom pointers.
20634 They are differentiated by the value of the 7th and 6th bits of the upper
20639 \begin_inset Tabular
20640 <lyxtabular version="3" rows="5" columns="5">
20642 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
20643 <column alignment="center" valignment="top" width="0">
20644 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
20645 <column alignment="center" valignment="top" width="0">
20646 <column alignment="left" valignment="top" rightline="true" width="0">
20647 <row topline="true" bottomline="true">
20648 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20656 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20664 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20672 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20677 rest of the pointer
20680 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20689 <row topline="true" bottomline="true">
20690 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20698 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20706 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20714 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20723 uuuuuu uuuuxxxx xxxxxxxx
20726 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20731 a 12-bit data pointer in data RAM memory
20735 <row bottomline="true">
20736 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20744 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20752 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20760 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20769 uxxxxx xxxxxxxx xxxxxxxx
20772 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20777 a 21-bit code pointer in FLASH memory
20781 <row bottomline="true">
20782 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20790 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20798 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20806 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20815 uuuuuu uuuuuuxx xxxxxxxx
20818 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20823 a 10-bit eeprom pointer in EEPROM memory
20827 <row bottomline="true">
20828 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20836 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20844 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20852 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20861 xxxxxx xxxxxxxx xxxxxxxx
20864 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20869 unimplemented pointer type
20880 Generic pointer are read and written with a set of library functions which
20881 read/write 1, 2, 3, 4 bytes.
20885 \layout Subsubsection
20887 Standard I/O Streams
20894 the type FILE is defined as:
20897 typedef char * FILE;
20900 This type is the stream type implemented I/O in the PIC18F devices.
20901 Also the standard input and output streams are declared in stdio.h:
20904 extern FILE * stdin;
20907 extern FILE * stdout;
20910 The FILE type is actually a generic pointer which defines one more type
20911 of generic pointers, the
20916 This new type has the format:
20920 \begin_inset Tabular
20921 <lyxtabular version="3" rows="2" columns="7">
20923 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
20924 <column alignment="center" valignment="top" width="0">
20925 <column alignment="center" valignment="top" leftline="true" width="0">
20926 <column alignment="center" valignment="top" leftline="true" width="0">
20927 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
20928 <column alignment="center" valignment="top" width="0">
20929 <column alignment="left" valignment="top" rightline="true" width="0">
20930 <row topline="true" bottomline="true">
20931 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20939 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20947 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20955 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20963 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20971 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20976 rest of the pointer
20979 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
20988 <row topline="true" bottomline="true">
20989 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
20997 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21005 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21013 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21021 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21029 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21041 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21046 upper byte high nubble is 0x2n, the rest are zeroes
21057 Currently implemented there are 3 types of streams defined:
21061 \begin_inset Tabular
21062 <lyxtabular version="3" rows="4" columns="4">
21064 <column alignment="center" valignment="top" leftline="true" width="0">
21065 <column alignment="center" valignment="top" leftline="true" width="0">
21066 <column alignment="center" valignment="top" leftline="true" width="0">
21067 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
21068 <row topline="true" bottomline="true">
21069 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21077 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21085 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21093 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21102 <row topline="true">
21103 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21111 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21121 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21129 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21134 Writes/Reads characters via the USART peripheral
21138 <row topline="true">
21139 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21147 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21157 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21165 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21170 Writes/Reads characters via the MSSP peripheral
21174 <row topline="true" bottomline="true">
21175 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21183 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21193 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21201 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21206 Writes/Reads characters via used defined functions
21217 The stream identifiers are declared as macros in the stdio.h header.
21220 In the libc library there exist the functions that are used to write to
21221 each of the above streams.
21224 \labelwidthstring 00.00.0000
21236 _stream_usart_putchar writes a character at the USART stream
21238 \labelwidthstring 00.00.0000
21250 _stream_mssp_putchar writes a character at the MSSP stream
21252 \labelwidthstring 00.00.0000
21254 putchar dummy function.
21255 This writes a character to a user specified manner.
21258 In order to increase performance
21262 is declared in stdio.h as having its parameter in WREG (it has the wparam
21264 In stdio.h exists the macro PUTCHAR(arg) that defines the putchar function
21265 in a user-friendly way.
21270 is the name of the variable that holds the character to print.
21271 An example follows:
21274 #include <pic18fregs.h>
21286 PORTA = c; /* dump character c to PORTA */
21299 stdout = STREAM_USER; /* this is not necessary, since stdout points
21302 * by default to STREAM_USER */
21305 printf (¨This is a printf test
21313 \layout Subsubsection
21318 PIC16 contains an implementation of the printf-family of functions.
21319 There exist the following functions:
21322 extern unsigned int sprintf(char *buf, char *fmt, ...);
21325 extern unsigned int vsprintf(char *buf, char *fmt, va_list ap);
21330 extern unsigned int printf(char *fmt, ...);
21333 extern unsigned int vprintf(char *fmt, va_lista ap);
21338 extern unsigned int fprintf(FILE *fp, char *fmt, ...);
21341 extern unsigned int vfprintf(FILE *fp, char *fmt, va_list ap);
21344 For sprintf and vsprintf
21348 should normally be a data pointer where the resulting string will be placed.
21349 No range checking is done so the user should allocate the necessery buffer.
21350 For fprintf and vfprintf
21354 should be a stream pointer (i.e.
21355 stdout, STREAM_MSSP, etc...).
21356 \layout Subsubsection
21361 The PIC18F family of microcontrollers supports a number of interrupt sources.
21362 A list of these interrupts is shown in the following table:
21366 \begin_inset Tabular
21367 <lyxtabular version="3" rows="11" columns="4">
21369 <column alignment="left" valignment="top" leftline="true" width="0">
21370 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
21371 <column alignment="left" valignment="top" leftline="true" width="0">
21372 <column alignment="center" valignment="top" leftline="true" rightline="true" width="0">
21373 <row topline="true" bottomline="true">
21374 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21382 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21390 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21398 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21407 <row topline="true">
21408 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21416 <cell multicolumn="1" alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21421 PORTB change interrupt
21424 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21432 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21437 EEPROM/FLASH write complete interrupt
21441 <row topline="true">
21442 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21450 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21455 INT0 external interrupt
21458 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21466 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21471 Bus collision interrupt
21475 <row topline="true">
21476 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21484 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21489 INT1 external interrupt
21492 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21500 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21505 Low voltage detect interrupt
21509 <row topline="true">
21510 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21518 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21523 INT2 external interrupt
21526 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21534 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21539 Parallel slave port interrupt
21543 <row topline="true">
21544 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21552 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21557 CCP1 module interrupt
21560 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21568 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21573 AD convertion complete interrupt
21577 <row topline="true">
21578 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21586 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21591 CCP2 module interrupt
21594 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21602 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21607 USART receive interrupt
21611 <row topline="true">
21612 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21620 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21625 TMR0 overflow interrupt
21628 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21636 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21641 USART transmit interrupt
21645 <row topline="true">
21646 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21654 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21659 TMR1 overflow interrupt
21662 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21670 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21675 SSP receive/transmit interrupt
21679 <row topline="true">
21680 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21688 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21693 TMR2 matches PR2 interrupt
21696 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21703 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21711 <row topline="true" bottomline="true">
21712 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
21720 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21725 TMR3 overflow interrupt
21728 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21735 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
21750 The prototypes for these names are defined in the header file
21757 In order to simplify signal handling, a number of macros is provided:
21759 \labelwidthstring 00.00.0000
21761 DEF_INTHIGH(name) begin the definition of the interrupt dispatch table for
21762 high priority interrupts.
21767 is the function name to use.
21769 \labelwidthstring 00.00.0000
21771 DEF_INTLOW(name) begin the definition of the interrupt dispatch table fo
21772 low priority interrupt.
21777 is the function name to use.
21779 \labelwidthstring 00.00.0000
21781 DEF_HANDLER(sig,handler) define a handler for signal
21785 \labelwidthstring 00.00.0000
21787 END_DEF end the declaration of the dispatch table.
21790 Additionally there are two more macros to simplify the declaration of the
21793 \labelwidthstring 00.00.0000
21797 SIGHANDLER(handler)
21799 this declares the function prototype for the
21805 \labelwidthstring 00.00.0000
21807 SIGHANDLERNAKED(handler) same as SIGHANDLER() but declares a naked function.
21810 An example of using the macros above is shown below:
21813 #include <pic18fregs.h>
21816 #include <signal.h>
21820 DEF_INTHIGH(high_int)
21823 DEF_HANDLER(SIG_TMR0, _tmr0_handler)
21826 DEF_HANDLER(SIG_BCOL, _bcol_handler)
21833 SIGHANDLER(_tmr0_handler)
21839 /* action to be taken when timer 0 overflows */
21846 SIGHANDLERNAKED(_bcol_handler)
21855 /* action to be taken when bus collision occurs */
21871 Special care should be taken when using the above scheme:
21874 do not place a colon (;) at the end of the DEF_* and END_DEF macros.
21877 when declaring SIGHANDLERNAKED handler never forget to use
21881 for proper returning.
21887 Here you can find some general tips for compiling programs with SDCC/pic16.
21888 \layout Subsubsection
21894 \begin_inset LatexCommand \index{PIC16!stack}
21898 size (that is 64 bytes) probably is enough for many programs.
21899 One must take care that when there are many levels of function nesting,
21900 or there is excessive usage of stack, its size should be extended.
21901 An example of such a case is the printf/sprintf family of functions.
21902 If you encounter problems like not being able to print integers, then you
21903 need to set the stack size around the maximum (256 for small stack model).
21904 The following diagram shows what happens when calling printf to print an
21908 printf () --> ltoa () --> ultoa () --> divschar ()
21911 It is should be understood that stack is easily consumed when calling complicate
21913 Using command line arguments like -
21923 -fommit-frame-pointer might reduce stack usage by not creating unnecessery
21925 Other ways to reduce stack usage may exist.
21931 The PIC16 Port currently does not pass SDCC's regression test
21932 \begin_inset LatexCommand \index{Regression test (PIC16)}
21937 \begin_inset LatexCommand \ref{sec:Quality-control}
21941 ) and thus the nightly regression tests for the PIC16 target are currently
21942 disabled for all hosts except for
21947 This means you can see the result of the PIC16 regression tests f.e.
21948 by checking the log files in
21949 \begin_inset LatexCommand \url{http://sdcc.sourceforge.net/regression_test_results/amd64-unknown-linux2.3/}
21953 (pick the most up to date file there, scroll down, lend a hand).
21959 There are several approaches to debugging your code.
21960 This chapter is meant to show your options and to give detail on some of
21965 When writing your code:
21968 write your code with debugging in mind (avoid duplicating code, put conceptually
21969 similar variables into structs, use structured code, have strategic points
21970 within your code where all variables are consistent, ...)
21973 run a syntax-checking tool like splint
21974 \begin_inset LatexCommand \index{splint (syntax checking tool)}
21979 \begin_inset LatexCommand \index{lint (syntax checking tool)}
21994 \begin_inset LatexCommand \ref{lyx:more-pedantic-SPLINT}
22001 for the high level code use a C-compiler (like f.e.
22002 GCC) to compile run and debug the code on your host.
22014 \begin_inset LatexCommand \ref{lyx:more-pedantic-SPLINT}
22018 ) on howto handle syntax extensions like __xdata, __at(), ...
22022 use another C-compiler to compile code for your target.
22023 Always an option but not recommended:) And not very likely to help you.
22024 If you seriously consider walking this path you should at least occasionally
22025 check portability of your code.
22026 Most commercial compiler vendors will offer an evaluation version so you
22027 can test compile your code or snippets of your code.
22030 Debugging on a simulator:
22033 there is a separate section about SDCDB (section
22034 \begin_inset LatexCommand \ref{cha:Debugging-with-SDCDB}
22041 or (8051 specific) use a freeware/commercial simulator which interfaces
22043 \begin_inset LatexCommand \index{AOMF, AOMF51}
22048 \begin_inset LatexCommand \ref{OMF file}
22052 ) optionally generated by SDCC.
22055 Debugging On-target:
22058 use a MCU port pin to serially output debug data to the RS232 port of your
22060 You'll probably want some level shifting device typically involving a MAX232
22062 If the hardware serial port of the MCU is not available search for 'Software
22063 UART' in your favourite search machine.
22066 use an on-target monitor.
22067 In this context a monitor is a small program which usually accepts commands
22068 via a serial line and allows to set program counter, to single step through
22069 a program and read/write memory locations.
22070 For the 8051 good examples of monitors are paulmon and cmon51 (see section
22072 \begin_inset LatexCommand \ref{sec:Related-open-source-tools}
22079 toggle MCU port pins at strategic points within your code and use an oscilloscop
22083 digital oscilloscope
22086 \begin_inset LatexCommand \index{Oscilloscope}
22090 with deep trace memory is really helpful especially if you have to debug
22091 a realtime application.
22092 If you need to monitor more pins than your oscilloscope provides you can
22093 sometimes get away with a small R-2R network.
22094 On a single channel oscilloscope you could f.e.
22095 monitor 2 push-pull driven pins by connecting one via a 10\SpecialChar ~
22097 \begin_inset Formula $\Omega$
22100 resistor and the other one by a 5\SpecialChar ~
22102 \begin_inset Formula $\Omega$
22105 resistor to the oscilloscope probe (check output drive capability of the
22106 pins you want to monitor).
22107 If you need to monitor many more pins a
22127 \begin_inset LatexCommand \index{ICE (in circuit emulator)}
22132 Usually very expensive.
22133 And very nice to have too.
22134 And usually locks you (for years...) to the devices the ICE can emulate.
22138 use a remote debugger.
22139 In most 8-bit systems the symbol information is not available on the target,
22140 and a complete debugger is too bulky for the target system.
22141 Therefore usually a debugger on the host system connects to an on-target
22142 debugging stub which accepts only primitive commands.
22145 Terms to enter into your favourite search engine could be 'remote debugging',
22146 'gdb stub' or 'inferior debugger'.
22150 use an on target hardware debugger.
22151 Some of the more modern MCUs include hardware support for setting break
22152 points and monitoring/changing variables by using dedicated hardware pins.
22153 This facility doesn't require additional code to run on the target and
22158 doesn't affect runtime behaviour until a breakpoint is hit.
22159 For the mcs51 most hardware debuggers use the AOMF
22160 \begin_inset LatexCommand \index{AOMF, AOMF51}
22165 \begin_inset LatexCommand \ref{OMF file}
22176 if you are not familiar with any of the following terms you're likely to
22177 run into problems rather sooner than later:
22194 As an embedded programmer you
22198 to know them so why not look them up
22202 you have problems?)
22205 tell someone else about your problem (actually this is a surprisingly effective
22206 means to hunt down the bug even if the listener is not familiar with your
22208 As 'failure to communicate' is probably one of the job-induced deformations
22209 of an embedded programmer this is highly encouraged.
22212 Debugging with SDCDB
22213 \begin_inset LatexCommand \label{cha:Debugging-with-SDCDB}
22218 \begin_inset LatexCommand \index{SDCDB (debugger)}
22225 SDCC is distributed with a source level debugger
22226 \begin_inset LatexCommand \index{Debugger}
22231 The debugger uses a command line interface, the command repertoire of the
22232 debugger has been kept as close to gdb
22233 \begin_inset LatexCommand \index{gdb}
22237 (the GNU debugger) as possible.
22238 The configuration and build process is part of the standard compiler installati
22239 on, which also builds and installs the debugger in the target directory
22240 specified during configuration.
22241 The debugger allows you debug BOTH at the C source and at the ASM source
22245 Compiling for Debugging
22259 \begin_inset LatexCommand \index{-\/-debug}
22263 option must be specified for all files for which debug information is to
22265 The compiler generates a .adb file for each of these files.
22266 The linker creates the .cdb
22267 \begin_inset LatexCommand \index{<file>.cdb}
22272 \begin_inset LatexCommand \index{<file>.adb}
22276 files and the address information.
22277 This .cdb is used by the debugger.
22280 How the Debugger Works
22293 -debug option is specified the compiler generates extra symbol information
22294 some of which are put into the assembler source and some are put into the
22296 Then the linker creates the .cdb file from the individual .adb files with
22297 the address information for the symbols.
22298 The debugger reads the symbolic information generated by the compiler &
22299 the address information generated by the linker.
22300 It uses the SIMULATOR (Daniel's S51) to execute the program, the program
22301 execution is controlled by the debugger.
22302 When a command is issued for the debugger, it translates it into appropriate
22303 commands for the simulator.
22304 (Currently SDCDM only connects to the simulator but
22309 \begin_inset LatexCommand \url{http://ec2drv.sf.net/}
22313 is an effort to connect directly to the hardware.)
22316 Starting the Debugger SDCDB
22319 The debugger can be started using the following command line.
22320 (Assume the file you are debugging has the file name foo).
22334 The debugger will look for the following files.
22337 foo.c - the source file.
22340 foo.cdb - the debugger symbol information file.
22343 foo.ihx - the Intel hex format
22344 \begin_inset LatexCommand \index{Intel hex format}
22351 SDCDB Command Line Options
22364 -directory=<source file directory> this option can used to specify the directory
22366 The debugger will look into the directory list specified for source, cdb
22368 The items in the directory list must be separated by ':', e.g.
22369 if the source files can be in the directories /home/src1 and /home/src2,
22380 -directory option should be -
22390 -directory=/home/src1:/home/src2.
22391 Note there can be no spaces in the option.
22395 -cd <directory> - change to the <directory>.
22398 -fullname - used by GUI front ends.
22401 -cpu <cpu-type> - this argument is passed to the simulator please see the
22402 simulator docs for details.
22405 -X <Clock frequency > this options is passed to the simulator please see
22406 the simulator docs for details.
22409 -s <serial port file> passed to simulator see the simulator docs for details.
22412 -S <serial in,out> passed to simulator see the simulator docs for details.
22415 -k <port number> passed to simulator see the simulator docs for details.
22418 SDCDB Debugger Commands
22421 As mentioned earlier the command interface for the debugger has been deliberatel
22422 y kept as close the GNU debugger gdb, as possible.
22423 This will help the integration with existing graphical user interfaces
22424 (like ddd, xxgdb or xemacs) existing for the GNU debugger.
22425 If you use a graphical user interface for the debugger you can skip this
22427 \layout Subsubsection*
22429 break [line | file:line | function | file:function]
22432 Set breakpoint at specified line or function:
22441 sdcdb>break foo.c:100
22443 sdcdb>break funcfoo
22445 sdcdb>break foo.c:funcfoo
22446 \layout Subsubsection*
22448 clear [line | file:line | function | file:function ]
22451 Clear breakpoint at specified line or function:
22460 sdcdb>clear foo.c:100
22462 sdcdb>clear funcfoo
22464 sdcdb>clear foo.c:funcfoo
22465 \layout Subsubsection*
22470 Continue program being debugged, after breakpoint.
22471 \layout Subsubsection*
22476 Execute till the end of the current function.
22477 \layout Subsubsection*
22482 Delete breakpoint number 'n'.
22483 If used without any option clear ALL user defined break points.
22484 \layout Subsubsection*
22486 info [break | stack | frame | registers ]
22489 info break - list all breakpoints
22492 info stack - show the function call stack.
22495 info frame - show information about the current execution frame.
22498 info registers - show content of all registers.
22499 \layout Subsubsection*
22504 Step program until it reaches a different source line.
22505 Note: pressing <return> repeats the last command.
22506 \layout Subsubsection*
22511 Step program, proceeding through subroutine calls.
22512 \layout Subsubsection*
22517 Start debugged program.
22518 \layout Subsubsection*
22523 Print type information of the variable.
22524 \layout Subsubsection*
22529 print value of variable.
22530 \layout Subsubsection*
22535 load the given file name.
22536 Note this is an alternate method of loading file for debugging.
22537 \layout Subsubsection*
22542 print information about current frame.
22543 \layout Subsubsection*
22548 Toggle between C source & assembly source.
22549 \layout Subsubsection*
22551 ! simulator command
22554 Send the string following '!' to the simulator, the simulator response is
22556 Note the debugger does not interpret the command being sent to the simulator,
22557 so if a command like 'go' is sent the debugger can loose its execution
22558 context and may display incorrect values.
22559 \layout Subsubsection*
22566 My name is Bobby Brown"
22569 Interfacing SDCDB with DDD
22572 The screenshot was converted from png to eps with:
22573 \begin_inset Quotes sld
22576 bmeps -c -e8f -p3 ddd_example.png >ddd_example.eps
22577 \begin_inset Quotes srd
22580 which produces a pretty compact eps file which is free from compression
22584 The screenshot was included in sdccman.lyx cvs version 1.120 but later removed
22585 as this broke the build system on Sourceforge (pdf-file was broken.
22586 pdflatex does not accept eps files).
22604 \begin_inset LatexCommand \url{http://svn.sourceforge.net/viewcvs.cgi/*checkout*/sdcc/trunk/sdcc/doc/figures/ddd_example.png}
22610 shows a screenshot of a debugging session with DDD
22611 \begin_inset LatexCommand \index{DDD (debugger)}
22615 (Unix only) on a simulated 8032.
22616 The debugging session might not run as smoothly as the screenshot suggests.
22617 The debugger allows setting of breakpoints, displaying and changing variables,
22618 single stepping through C and assembler code.
22621 The source was compiled with
22644 -debug ddd_example.c
22657 and DDD was invoked with
22664 ddd -debugger 'sdcdb -cpu 8032 ddd_example'
22667 Interfacing SDCDB with XEmacs
22668 \begin_inset LatexCommand \index{XEmacs}
22673 \begin_inset LatexCommand \index{Emacs}
22680 Two files (in emacs lisp) are provided for the interfacing with XEmacs,
22681 sdcdb.el and sdcdbsrc.el.
22682 These two files can be found in the $(prefix)/bin directory after the installat
22684 These files need to be loaded into XEmacs for the interface to work.
22685 This can be done at XEmacs startup time by inserting the following into
22686 your '.xemacs' file (which can be found in your HOME directory):
22692 (load-file sdcdbsrc.el)
22698 .xemacs is a lisp file so the () around the command is REQUIRED.
22699 The files can also be loaded dynamically while XEmacs is running, set the
22700 environment variable 'EMACSLOADPATH' to the installation bin directory
22701 (<installdir>/bin), then enter the following command ESC-x load-file sdcdbsrc.
22702 To start the interface enter the following command:
22716 You will prompted to enter the file name to be debugged.
22721 The command line options that are passed to the simulator directly are bound
22722 to default values in the file sdcdbsrc.el.
22723 The variables are listed below, these values maybe changed as required.
22726 sdcdbsrc-cpu-type '51
22729 sdcdbsrc-frequency '11059200
22732 sdcdbsrc-serial nil
22735 The following is a list of key mapping for the debugger interface.
22746 ;;key\SpecialChar ~
22760 binding\SpecialChar ~
22784 ;;---\SpecialChar ~
22798 -------\SpecialChar ~
22840 sdcdb-next-from-src\SpecialChar ~
22868 sdcdb-back-from-src\SpecialChar ~
22896 sdcdb-cont-from-src\SpecialChar ~
22906 SDCDB continue command
22924 sdcdb-step-from-src\SpecialChar ~
22952 sdcdb-whatis-c-sexp\SpecialChar ~
22962 SDCDB ptypecommand for data at
23029 sdcdbsrc-delete\SpecialChar ~
23043 SDCDB Delete all breakpoints if no arg
23092 given or delete arg (C-u arg x)
23110 sdcdbsrc-frame\SpecialChar ~
23125 SDCDB Display current frame if no arg,
23174 given or display frame arg
23241 sdcdbsrc-goto-sdcdb\SpecialChar ~
23251 Goto the SDCDB output buffer
23269 sdcdb-print-c-sexp\SpecialChar ~
23280 SDCDB print command for data at
23347 sdcdbsrc-goto-sdcdb\SpecialChar ~
23357 Goto the SDCDB output buffer
23375 sdcdbsrc-mode\SpecialChar ~
23391 Toggles Sdcdbsrc mode (turns it off)
23406 sdcdb-finish-from-src\SpecialChar ~
23414 SDCDB finish command
23429 sdcdb-break\SpecialChar ~
23447 Set break for line with point
23462 sdcdbsrc-mode\SpecialChar ~
23478 Toggle Sdcdbsrc mode
23493 sdcdbsrc-srcmode\SpecialChar ~
23516 Here are a few guidelines that will help the compiler generate more efficient
23517 code, some of the tips are specific to this compiler others are generally
23518 good programming practice.
23521 Use the smallest data type to represent your data-value.
23522 If it is known in advance that the value is going to be less than 256 then
23523 use an 'unsigned char' instead of a 'short' or 'int'.
23524 Please note, that ANSI C requires both signed and unsigned chars to be
23525 promoted to 'signed int'
23526 \begin_inset LatexCommand \index{promotion to signed int}
23531 \begin_inset Marginal
23542 before doing any operation.
23544 \begin_inset LatexCommand \index{type promotion}
23549 \begin_inset LatexCommand \label{type promotion}
23553 can be omitted, if the result is the same.
23554 The effect of the promotion rules together with the sign-extension is often
23561 unsigned char uc = 0xfe;
23563 if (uc * uc < 0) /* this is true! */
23582 (int) uc * (int) uc = (int) 0xfe * (int) 0xfe = (int) 0xfc04 = -1024
23592 (unsigned char) -12 / (signed char) -3 = ...
23595 No, the result is not 4:
23600 (int) (unsigned char) -12 / (int) (signed char) -3 =
23602 (int) (unsigned char) 0xf4 / (int) (signed char) 0xfd =
23604 (int) 0x00f4 / (int) 0xfffd =
23606 (int) 0x00f4 / (int) 0xfffd =
23608 (int) 244 / (int) -3 =
23610 (int) -81 = (int) 0xffaf;
23613 Don't complain, that gcc gives you a different result.
23614 gcc uses 32 bit ints, while SDCC uses 16 bit ints.
23615 Therefore the results are different.
23618 \begin_inset Quotes sld
23622 \begin_inset Quotes srd
23630 If well-defined overflow characteristics are important and negative values
23631 are not, or if you want to steer clear of sign-extension problems when
23632 manipulating bits or bytes, use one of the corresponding unsigned types.
23633 (Beware when mixing signed and unsigned values in expressions, though.)
23635 Although character types (especially unsigned char) can be used as "tiny"
23636 integers, doing so is sometimes more trouble than it's worth, due to unpredicta
23637 ble sign extension and increased code size.
23641 Use unsigned when it is known in advance that the value is not going to
23643 This helps especially if you are doing division or multiplication, bit-shifting
23644 or are using an array index.
23647 NEVER jump into a LOOP.
23650 Declare the variables to be local
23651 \begin_inset LatexCommand \index{local variables}
23655 whenever possible, especially loop control variables (induction).
23658 Since the compiler does not always do implicit integral promotion, the programme
23659 r should do an explicit cast when integral promotion is required.
23662 Reducing the size of division, multiplication & modulus operations can reduce
23663 code size substantially.
23664 Take the following code for example.
23670 foobar(unsigned int p1, unsigned char ch)
23678 unsigned char ch1 = p1 % ch ;
23689 For the modulus operation the variable ch will be promoted to unsigned int
23690 first then the modulus operation will be performed (this will lead to a
23691 call to support routine _moduint()), and the result will be casted to a
23693 If the code is changed to
23698 foobar(unsigned int p1, unsigned char ch)
23706 unsigned char ch1 = (unsigned char)p1 % ch ;
23717 It would substantially reduce the code generated (future versions of the
23718 compiler will be smart enough to detect such optimization opportunities).
23722 Have a look at the assembly listing to get a
23723 \begin_inset Quotes sld
23727 \begin_inset Quotes srd
23730 for the code generation.
23733 Porting code from or to other compilers
23734 \begin_inset LatexCommand \label{sec:Porting-code-to-other-compilers}
23741 check whether endianness of the compilers differs and adapt where needed.
23744 check the device specific header files
23745 \begin_inset LatexCommand \index{Header files}
23750 \begin_inset LatexCommand \index{Include files}
23754 for compiler specific syntax.
23755 Eventually include the file <compiler.h
23756 \begin_inset LatexCommand \index{compiler.h (include file)}
23761 \begin_inset LatexCommand \url{http://svn.sourceforge.net/viewvc/sdcc/trunk/sdcc/device/include/mcs51/compiler.h?view=markup}
23765 to allow using common header files.
23768 \begin_inset LatexCommand \url{http://svn.sourceforge.net/viewvc/sdcc/trunk/sdcc/device/include/mcs51/cc2510fx.h?view=markup}
23775 check whether the startup code contains the correct initialization (watchdog,
23779 check whether the sizes of short, int, long match.
23782 check if some 16 or 32 bit hardware registers require a specific addressing
23783 order (least significant or most significant byte first) and adapt if needed
23792 relate to time and not to lower/upper memory location here, so this is
23797 the same as endianness).
23800 check whether the keyword
23804 is used where needed.
23805 The compilers might differ in their optimization characteristics (as different
23806 versions of the same compiler might also use more clever optimizations
23807 this is good idea anyway).
23809 \begin_inset LatexCommand \ref{sub:Common-interrupt-pitfall-volatile}
23816 check that the compilers are not told to supress warnings.
23819 check and convert compiler specific extensions (interrupts, memory areas,
23823 check for differences in type promotion.
23824 Especially check for math operations on
23833 For the sake of C99 compatibility SDCC will probably promote these to
23837 more often than other compilers.
23838 Eventually insert explicit casts to
23847 Also check that the ~\SpecialChar ~
23849 \begin_inset LatexCommand \index{\~\/ Operator}
23856 \begin_inset LatexCommand \index{bit}
23862 variables, use the !\SpecialChar ~
23865 \begin_inset LatexCommand \ref{type promotion}
23870 \begin_inset LatexCommand \ref{sec:Compatibility-with-previous}
23877 check the assembly code generated for interrupt routines (f.e.
23878 for calls to possibly non-reentrant library functions).
23881 check whether timing loops result in proper timing (or preferably consider
23882 a rewrite of the code with timer based delays instead).
23885 check for differences in printf parameters (some compilers push (va_arg
23886 \begin_inset LatexCommand \index{vararg, va\_arg}
23890 ) char variables as
23894 others push them as
23900 \begin_inset LatexCommand \ref{sec:Compatibility-with-previous}
23907 check the resulting memory map
23908 \begin_inset LatexCommand \index{Memory map}
23913 Usage of different memory spaces: code, stack, data (for mcs51/ds390 additional
23914 ly idata, pdata, xdata).
23915 Eventually check if unexpected library functions are included.
23919 \begin_inset LatexCommand \index{Tools}
23923 included in the distribution
23927 \begin_inset Tabular
23928 <lyxtabular version="3" rows="12" columns="3">
23930 <column alignment="left" valignment="top" leftline="true" width="0pt">
23931 <column alignment="left" valignment="top" leftline="true" width="0pt">
23932 <column alignment="left" valignment="top" leftline="true" rightline="true" width="0pt">
23933 <row topline="true" bottomline="true">
23934 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
23942 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
23950 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
23959 <row topline="true">
23960 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
23968 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
23973 Simulator for various architectures
23976 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
23985 <row topline="true">
23986 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
23994 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24000 \begin_inset LatexCommand \index{Header files}
24005 \begin_inset LatexCommand \index{Include files}
24012 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24017 sdcc/support/scripts
24021 <row topline="true">
24022 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24030 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24035 header file conversion
24038 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24043 sdcc/support/scripts
24047 <row topline="true">
24048 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24056 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24064 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24082 <row topline="true">
24083 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24091 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24099 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24117 <row topline="true">
24118 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24126 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24134 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24152 <row topline="true">
24153 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24161 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24169 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24187 <row topline="true">
24188 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24196 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24204 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24222 <row topline="true">
24223 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24231 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24239 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24257 <row topline="true">
24258 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24266 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24274 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24292 <row topline="true" bottomline="true">
24293 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24301 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24307 \begin_inset LatexCommand \index{packihx (tool)}
24314 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24342 \begin_inset LatexCommand \index{Documentation}
24346 included in the distribution
24350 \begin_inset Tabular
24351 <lyxtabular version="3" rows="10" columns="2">
24353 <column alignment="left" valignment="top" leftline="true" width="0">
24354 <column alignment="left" valignment="top" leftline="true" rightline="true" width="0pt">
24355 <row topline="true" bottomline="true">
24356 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24364 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24369 Where to get / filename
24373 <row topline="true">
24374 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24379 SDCC Compiler User Guide
24382 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24387 You're reading it right now
24391 <row topline="true">
24392 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24400 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24409 <row topline="true">
24410 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24416 \begin_inset LatexCommand \index{asXXXX (as-gbz80, as-hc08, asx8051, as-z80)}
24421 \begin_inset LatexCommand \index{Assembler documentation}
24425 Assemblers and ASLINK
24426 \begin_inset LatexCommand \index{aslink}
24431 \begin_inset LatexCommand \index{Linker documentation}
24438 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24443 sdcc/as/doc/asxhtm.html
24447 <row topline="true">
24448 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24453 SDCC regression test
24454 \begin_inset LatexCommand \index{Regression test}
24461 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24466 sdcc/doc/test_suite_spec.pdf
24470 <row topline="true">
24471 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24479 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24488 <row topline="true">
24489 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24494 Notes on debugging with SDCDB
24495 \begin_inset LatexCommand \index{SDCDB (debugger)}
24502 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24507 sdcc/debugger/README
24511 <row topline="true">
24512 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24517 Software simulator for microcontrollers
24520 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24547 <row topline="true">
24548 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24553 Temporary notes on the pic16
24554 \begin_inset LatexCommand \index{PIC16}
24561 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24566 sdcc/src/pic16/NOTES
24570 <row topline="true" bottomline="true">
24571 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24576 SDCC internal documentation (debugging file format)
24579 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24615 Related open source tools
24616 \begin_inset LatexCommand \label{sec:Related-open-source-tools}
24621 \begin_inset LatexCommand \index{Related tools}
24629 \begin_inset Tabular
24630 <lyxtabular version="3" rows="14" columns="3">
24632 <column alignment="left" valignment="top" leftline="true" width="0pt">
24633 <column alignment="block" valignment="top" leftline="true" width="30line%">
24634 <column alignment="left" valignment="top" leftline="true" rightline="true" width="0pt">
24635 <row topline="true" bottomline="true">
24636 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24644 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24652 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24661 <row topline="true">
24662 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24668 \begin_inset LatexCommand \index{gpsim (pic simulator)}
24675 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24683 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24689 \begin_inset LatexCommand \url{http://www.dattalo.com/gnupic/gpsim.html}
24697 <row topline="true">
24698 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24704 \begin_inset LatexCommand \index{gputils (pic tools)}
24711 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24719 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24725 \begin_inset LatexCommand \url{http://sourceforge.net/projects/gputils}
24733 <row topline="true">
24734 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24742 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24750 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24756 \begin_inset LatexCommand \url{http://freshmeat.net/projects/flp5/}
24764 <row topline="true">
24765 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24773 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24778 Tools for Silicon Laboratories JTAG debug adapter, partly based on SDCDB
24782 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24788 \begin_inset LatexCommand \url{http://sourceforge.net/projects/ec2drv}
24796 <row topline="true">
24797 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24803 \begin_inset LatexCommand \index{indent (source formatting tool)}
24810 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24815 Formats C source - Master of the white spaces
24818 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24824 \begin_inset LatexCommand \url{http://directory.fsf.org/GNU/indent.html}
24832 <row topline="true">
24833 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24839 \begin_inset LatexCommand \index{srecord (bin, hex, ... tool)}
24846 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24851 Object file conversion, checksumming, ...
24854 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24860 \begin_inset LatexCommand \url{http://sourceforge.net/projects/srecord}
24868 <row topline="true">
24869 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24875 \begin_inset LatexCommand \index{objdump (tool)}
24882 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24887 Object file conversion, ...
24890 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24895 Part of binutils (should be there anyway)
24899 <row topline="true">
24900 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24908 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24913 8051 monitor (hex up-/download, single step, disassemble)
24916 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24922 \begin_inset LatexCommand \url{http://sourceforge.net/projects/cmon51}
24930 <row topline="true">
24931 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24937 \begin_inset LatexCommand \index{doxygen (source documentation tool)}
24944 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24949 Source code documentation system
24952 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24958 \begin_inset LatexCommand \url{http://www.doxygen.org}
24966 <row topline="true">
24967 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24975 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
24980 IDE (has anyone tried integrating SDCC & SDCDB? Unix only)
24983 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
24989 \begin_inset LatexCommand \url{http://www.kdevelop.org}
24997 <row topline="true">
24998 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25006 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25011 8051 monitor (hex up-/download, single step, disassemble)
25014 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
25020 \begin_inset LatexCommand \url{http://www.pjrc.com/tech/8051/paulmon2.html}
25028 <row topline="true">
25029 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25035 \begin_inset LatexCommand \index{splint (syntax checking tool)}
25042 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25047 Statically checks c sources (see
25048 \begin_inset LatexCommand \ref{lyx:more-pedantic-SPLINT}
25055 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
25061 \begin_inset LatexCommand \url{http://www.splint.org}
25069 <row topline="true" bottomline="true">
25070 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25076 \begin_inset LatexCommand \index{DDD (debugger)}
25083 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25088 Debugger, serves nicely as GUI to SDCDB
25089 \begin_inset LatexCommand \index{SDCDB (debugger)}
25096 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
25102 \begin_inset LatexCommand \url{http://www.gnu.org/software/ddd/}
25119 Related documentation / recommended reading
25123 \begin_inset Tabular
25124 <lyxtabular version="3" rows="7" columns="3">
25126 <column alignment="left" valignment="top" leftline="true" width="0pt">
25127 <column alignment="center" valignment="top" leftline="true" width="0">
25128 <column alignment="left" valignment="top" leftline="true" rightline="true" width="0pt">
25129 <row topline="true" bottomline="true">
25130 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25138 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25146 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
25155 <row topline="true">
25156 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25173 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25179 \begin_inset LatexCommand \index{C Reference card}
25186 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
25192 \begin_inset LatexCommand \url{http://refcards.com/refcards/c/index.html}
25200 <row topline="true">
25201 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25209 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25215 \begin_inset LatexCommand \index{C FAQ}
25222 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
25228 \begin_inset LatexCommand \url{http://www.c-faq.com}
25236 <row topline="true">
25237 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25245 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25251 \begin_inset Quotes sld
25255 \begin_inset Quotes srd
25261 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
25269 \begin_inset LatexCommand \url{http://www.open-std.org/jtc1/sc22/wg14/www/standards.html#9899}
25277 <row topline="true">
25278 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25286 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25292 \begin_inset Quotes sld
25295 Extensions for Embedded C
25296 \begin_inset Quotes srd
25302 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
25310 \begin_inset LatexCommand \url{http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1021.pdf}
25318 <row topline="true">
25319 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25326 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25331 Latest datasheet of target CPU
25334 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
25343 <row topline="true" bottomline="true">
25344 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25351 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25356 Revision history of datasheet
25359 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
25377 Application notes specifically for SDCC
25380 SDCC makes no claims about the completeness of this list and about up-to-datenes
25381 s or correctness of the application notes
25382 \begin_inset LatexCommand \index{Application notes}
25392 \begin_inset Tabular
25393 <lyxtabular version="3" rows="7" columns="3">
25395 <column alignment="block" valignment="top" leftline="true" width="17col%">
25396 <column alignment="block" valignment="top" leftline="true" width="27col%">
25397 <column alignment="block" valignment="top" leftline="true" rightline="true" width="57col%">
25398 <row topline="true" bottomline="true">
25399 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25409 <cell alignment="left" valignment="top" topline="true" bottomline="true" leftline="true" usebox="none">
25419 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
25430 <row topline="true">
25431 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25441 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25448 Using the SDCC Compiler for the DS80C400
25449 \begin_inset LatexCommand \index{DS80C400}
25456 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
25464 \begin_inset LatexCommand \url{http://pdfserv.maxim-ic.com/en/an/AN3346.pdf}
25472 <row topline="true">
25473 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25483 <cell multicolumn="1" alignment="left" valignment="top" topline="true" leftline="true" usebox="none" width="30line%">
25490 Using the Free SDCC C Compiler to Develop Firmware for the DS89C420/430/440/450
25491 \begin_inset LatexCommand \index{DS89C4x0}
25495 Family of Microcontrollers
25498 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
25506 \begin_inset LatexCommand \url{http://pdfserv.maxim-ic.com/en/an/AN3477.pdf}
25514 <row topline="true">
25515 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25522 Silicon Laboratories / Cygnal
25525 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25532 Integrating SDCC 8051 Tools Into The Silicon Labs IDE
25533 \begin_inset LatexCommand \index{IDE}
25540 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
25548 \begin_inset LatexCommand \url{http://www.silabs.com/public/documents/tpub_doc/anote/Microcontrollers/en/an198.pdf}
25556 <row topline="true">
25557 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25564 Ramtron / Goal Semiconductor
25567 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25574 Interfacing SDCC to Syn and Textpad
25577 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
25585 \begin_inset LatexCommand \url{http://www.ramtron.com/doc/Products/Microcontroller/Support_Tools.asp}
25593 <row topline="true">
25594 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25601 Ramtron / Goal Semiconductor
25604 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25611 Installing and Configuring SDCC and Crimson Editor
25614 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
25622 \begin_inset LatexCommand \url{http://www.ramtron.com/doc/Products/Microcontroller/Support_Tools.asp}
25630 <row topline="true" bottomline="true">
25631 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25641 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
25648 MSC12xx Programming with SDCC
25651 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
25659 \begin_inset LatexCommand \url{http://focus.ti.com/general/docs/lit/getliterature.tsp?literatureNumber=sbaa109&fileType=pdf}
25677 Some questions answered, some pointers given - it might be time to in turn
25685 can you solve your project with the selected microcontroller? Would you
25686 find out early or rather late that your target is too small/slow/whatever?
25687 Can you switch to a slightly better device if it doesn't fit?
25690 should you solve the problem with an 8 bit CPU? Or would a 16/32 bit CPU
25691 and/or another programming language be more adequate? Would an operating
25692 system on the target device help?
25695 if you solved the problem, will the marketing department be happy?
25698 if the marketing department is happy, will customers be happy?
25701 if you're the project manager, marketing department and maybe even the customer
25702 in one person, have you tried to see the project from the outside?
25705 is the project done if you think it is done? Or is just that other interface/pro
25706 tocol/feature/configuration/option missing? How about website, manual(s),
25707 internationali(z|s)ation, packaging, labels, 2nd source for components,
25708 electromagnetic compatability/interference, documentation for production,
25709 production test software, update mechanism, patent issues?
25712 is your project adequately positioned in that magic triangle: fame, fortune,
25716 Maybe not all answers to these questions are known and some answers may
25721 , nevertheless knowing these questions may help you to avoid burnout
25727 burnout is bad for electronic devices, programmers and motorcycle tyres
25731 Chances are you didn't want to hear some of them...
25735 \begin_inset LatexCommand \index{Support}
25742 SDCC has grown to be a large project.
25743 The compiler alone (without the preprocessor, assembler and linker) is
25744 well over 150,000 lines of code (blank stripped).
25745 The open source nature of this project is a key to its continued growth
25747 You gain the benefit and support of many active software developers and
25749 Is SDCC perfect? No, that's why we need your help.
25750 The developers take pride in fixing reported bugs.
25751 You can help by reporting the bugs and helping other SDCC users.
25752 There are lots of ways to contribute, and we encourage you to take part
25753 in making SDCC a great software package.
25757 The SDCC project is hosted on the SDCC sourceforge site at
25758 \begin_inset LatexCommand \htmlurl{http://sourceforge.net/projects/sdcc}
25763 You'll find the complete set of mailing lists
25764 \begin_inset LatexCommand \index{Mailing list(s)}
25768 , forums, bug reporting system, patch submission
25769 \begin_inset LatexCommand \index{Patch submission}
25774 \begin_inset LatexCommand \index{download}
25778 area and Subversion code repository
25779 \begin_inset LatexCommand \index{Subversion code repository}
25787 \begin_inset LatexCommand \index{Bug reporting}
25792 \begin_inset LatexCommand \index{Reporting bugs}
25799 The recommended way of reporting bugs is using the infrastructure of the
25801 You can follow the status of bug reports there and have an overview about
25805 Bug reports are automatically forwarded to the developer mailing list and
25806 will be fixed ASAP.
25807 When reporting a bug, it is very useful to include a small test program
25808 (the smaller the better) which reproduces the problem.
25809 If you can isolate the problem by looking at the generated assembly code,
25810 this can be very helpful.
25811 Compiling your program with the -
25822 \begin_inset LatexCommand \index{-\/-dumpall}
25826 option can sometimes be useful in locating optimization problems.
25827 When reporting a bug please make sure you:
25830 Attach the code you are compiling with SDCC.
25834 Specify the exact command you use to run SDCC, or attach your Makefile.
25838 Specify the SDCC version (type "
25844 "), your platform, and operating system.
25848 Provide an exact copy of any error message or incorrect output.
25852 Put something meaningful in the subject of your message.
25855 Please attempt to include these 5 important parts, as applicable, in all
25856 requests for support or when reporting any problems or bugs with SDCC.
25857 Though this will make your message lengthy, it will greatly improve your
25858 chance that SDCC users and developers will be able to help you.
25859 Some SDCC developers are frustrated by bug reports without code provided
25860 that they can use to reproduce and ultimately fix the problem, so please
25861 be sure to provide sample code if you are reporting a bug!
25864 Please have a short check that you are using a recent version of SDCC and
25865 the bug is not yet known.
25866 This is the link for reporting bugs:
25867 \begin_inset LatexCommand \htmlurl{http://sourceforge.net/tracker/?group_id=599&atid=100599}
25872 With SDCC on average having more than 200 downloads
25873 \begin_inset LatexCommand \index{download}
25877 on sourceforge per day
25883 220 daily downloads on average Jan-Sept 2006 and about 150 daily downloads
25884 between 2002 and 2005.
25885 This does not include other methods of distribution.
25888 there must be some users.
25889 So it's not exactly easy to find a new bug.
25890 If you find one we need it:
25892 reporting bugs is good
25897 Requesting Features
25898 \begin_inset LatexCommand \label{sub:Requesting-Features}
25903 \begin_inset LatexCommand \index{Feature request}
25908 \begin_inset LatexCommand \index{Requesting features}
25915 Like bug reports feature requests are forwarded to the developer mailing
25917 This is the link for requesting features:
25918 \begin_inset LatexCommand \htmlurl{http://sourceforge.net/tracker/?group_id=599&atid=350599}
25928 Like bug reports contributed patches are forwarded to the developer mailing
25930 This is the link for submitting patches
25931 \begin_inset LatexCommand \index{Patch submission}
25936 \begin_inset LatexCommand \url{http://sourceforge.net/tracker/?group_id=599&atid=300599}
25943 You need to specify some parameters to the
25947 command for the patches to be useful.
25948 If you modified more than one file a patch created f.e.
25953 \begin_inset Quotes sld
25956 diff -Naur unmodified_directory modified_directory >my_changes.patch
25957 \begin_inset Quotes srd
25963 will be fine, otherwise
25967 \begin_inset Quotes sld
25970 diff -u sourcefile.c.orig sourcefile.c >my_changes.patch
25971 \begin_inset Quotes srd
25984 These links should take you directly to the
25985 \begin_inset LatexCommand \url[Mailing lists]{http://sourceforge.net/mail/?group_id=599}
25995 Traffic on sdcc-devel and sdcc-user is about 100 mails/month each not counting
25996 automated messages (mid 2003)
26000 \begin_inset LatexCommand \url[Forums]{http://sourceforge.net/forum/?group_id=599}
26005 \begin_inset LatexCommand \index{Mailing list(s)}
26009 and forums are archived and searchable so if you are lucky someone already
26010 had a similar problem.
26011 While mails to the lists themselves are delivered promptly their web front
26012 end on sourceforge sometimes shows a severe time lag (up to several weeks),
26013 if you're seriously using SDCC please consider subscribing to the lists.
26019 You can follow the status of the Subversion version
26020 \begin_inset LatexCommand \index{version}
26024 of SDCC by watching the Changelog
26025 \begin_inset LatexCommand \index{Changelog}
26029 in the Subversion repository
26032 \begin_inset LatexCommand \htmlurl{http://svn.sourceforge.net/viewcvs.cgi/*checkout*/sdcc/trunk/sdcc/ChangeLog}
26039 Subversion Source Code Repository
26048 or the filenames of the snapshot versions of SDCC include date and its
26050 \begin_inset LatexCommand \index{Subversion code repository}
26055 Subversion allows to download the source of recent or previous versions
26057 \begin_inset LatexCommand \url{http://sourceforge.net/svn/?group_id=599}
26061 (by number or by date).
26062 An on-line source code browser and detailled instructions are also available
26064 SDCC versions starting from 1999 up to now are available (currently the
26065 versions prior to the conversion from cvs
26066 \begin_inset LatexCommand \index{cvs|see{Subversion}}
26070 to Subversion (April 2006) are either by accessible by Subversion or by
26075 \begin_inset LatexCommand \index{Release policy}
26082 Historically there often were long delays between official releases and
26083 the sourceforge download area tends to get not updated at all.
26084 Excuses in the past might have referred to problems with live range analysis,
26085 but as this was fixed a while ago, the current problem is that another
26086 excuse has to be found.
26087 Kidding aside, we have to get better there! On the other hand there are
26088 daily snapshots available at
26089 \begin_inset LatexCommand \htmlurl[snap]{http://sdcc.sourceforge.net/snap.php}
26093 , and you can always build the very last version (hopefully with many bugs
26094 fixed, and features added) from the source code available at
26095 \begin_inset LatexCommand \htmlurl[Source]{http://sdcc.sourceforge.net/snap.php#Source}
26101 \begin_inset LatexCommand \index{wiki}
26106 \begin_inset LatexCommand \index{Release wiki}
26111 \begin_inset LatexCommand \url{http://sdcc.sf.net/release_wiki/}
26115 also holds some information about past and future releases.
26119 \begin_inset LatexCommand \index{Examples}
26126 You'll find some small examples in the directory
26128 sdcc/device/examples/.
26131 More examples and libraries are available at
26133 The SDCC Open Knowledge Resource
26134 \begin_inset LatexCommand \url{http://sdccokr.dl9sec.de/}
26141 \begin_inset LatexCommand \url{http://www.pjrc.com/tech/8051/}
26148 I did insert a reference to Paul's web site here although it seems rather
26149 dedicated to a specific 8032 board (I think it's okay because it f.e.
26150 shows LCD/Harddisc interface and has a free 8051 monitor.
26151 Independent 8032 board vendors face hard competition of heavily subsidized
26152 development boards anyway).
26155 Maybe we should include some links to real world applications.
26156 Preferably pointer to pointers (one for each architecture) so this stays
26161 \begin_inset LatexCommand \label{sec:Quality-control}
26166 \begin_inset LatexCommand \index{Quality control}
26173 The compiler is passed through nightly compile and build checks.
26179 \begin_inset LatexCommand \index{Regression test}
26183 check that SDCC itself compiles flawlessly on several host platforms (i386,
26184 Opteron, 64 bit Alpha, ppc64, MacOS X on PPC, Solaris on Sparc) and checks
26185 the quality of the code generated by SDCC by running the code for several
26186 target platforms through simulators.
26187 The regression test suite comprises more than 100 files which expand to
26188 more than 500 test cases which include more than 4500 tests.
26189 The results of these tests are published daily on SDCC's snapshot page
26190 (click on the red or green symbols on the right side of
26191 \begin_inset LatexCommand \url{http://sdcc.sourceforge.net/snap.php}
26198 There is a separate document
26201 \begin_inset LatexCommand \index{Test suite}
26208 \begin_inset LatexCommand \url{http://sdcc.sourceforge.net/doc/test_suite_spec.pdf}
26212 about the regression test suite.
26215 You'll find the test code in the directory
26217 sdcc/support/regression
26220 You can run these tests manually by running
26224 in this directory (or f.e.
26229 \begin_inset Quotes sld
26233 \begin_inset Quotes srd
26239 if you don't want to run the complete tests).
26240 The test code might also be interesting if you want to look for examples
26241 \begin_inset LatexCommand \index{Examples}
26245 checking corner cases of SDCC or if you plan to submit patches
26246 \begin_inset LatexCommand \index{Patch submission}
26253 The 14bit pic port uses a different set of regression tests
26254 \begin_inset LatexCommand \index{Regression test (PIC14)}
26258 , you'll find them in the directory
26260 sdcc/src/regression
26265 Use of SDCC in Education
26278 the phrase "use in education" might evoke the association "
26282 fit for use in education".
26283 This connotation is not intended but nevertheless risked as the licensing
26284 of SDCC makes it difficult to offer educational discounts
26288 If your rationales are to:
26291 give students a chance to understand the
26295 steps of code generation
26298 have a curriculum that can be extended for years.
26299 Then you could use an fpga board as target and your curriculum will seamlessly
26300 extend from logic synthesis (
26301 \begin_inset LatexCommand \url[http://www.opencores.org]{opencores.org}
26306 \begin_inset LatexCommand \url[Oregano]{http://www.oregano.at/ip/ip01.htm}
26310 ), over assembly programming, to C to FPGA compilers (
26311 \begin_inset LatexCommand \url[FPGAC]{http://sf.net/projects/fpgac}
26318 be able to insert excursions about skills like using a revision control
26319 system, submitting/applying patches, using a type-setting (as opposed to
26320 word-processing) engine LyX/LaTeX, using
26321 \begin_inset LatexCommand \url[SourceForge]{http://www.sf.net}
26326 \begin_inset LatexCommand \url[netiquette]{http://en.wikipedia.org/wiki/Netiquette}
26330 , understanding BSD/LGPL/GPL/Proprietary licensing, growth models of Open
26331 Source Software, CPU simulation, compiler regression tests
26332 \begin_inset LatexCommand \index{Regression test}
26339 And if there should be a shortage of ideas then you can always point students
26340 to the ever-growing feature request list
26341 \begin_inset LatexCommand \htmlurl{http://sourceforge.net/tracker/?group_id=599&atid=350599}
26348 not tie students to a specific host platform and instead allow them to use
26353 choice (among them Alpha, i386, i386_64, MacOs, Mips, Sparc, Windows and
26355 \begin_inset LatexCommand \url[OLPC]{http://www.laptop.org}
26362 not encourage students to use illegal copies of educational software
26365 be immune to licensing/availability/price changes of the chosen tool chain
26368 be able to change to a new target platform without having to adopt a new
26372 have complete control over and insight into the tool chain
26375 make your students aware about the pros and cons of open source software
26379 give back to the public as you are probably at least partially publically
26383 give students a chance to publically prove their skills and to possibly
26384 see a world wide impact
26387 then SDCC is probably among the first choices.
26388 Well, probably SDCC might be the only choice.
26391 SDCC Technical Data
26395 \begin_inset LatexCommand \index{Optimizations}
26402 SDCC performs a host of standard optimizations in addition to some MCU specific
26407 Sub-expression Elimination
26408 \begin_inset LatexCommand \index{Subexpression elimination}
26415 The compiler does local and
26441 will be translated to
26453 Some subexpressions are not as obvious as the above example, e.g.:
26463 In this case the address arithmetic a->b[i] will be computed only once;
26464 the equivalent code in C would be.
26476 The compiler will try to keep these temporary variables in registers.
26479 Dead-Code Elimination
26480 \begin_inset LatexCommand \index{Dead-code elimination}
26501 i = 1; \SpecialChar ~
26510 global = 1;\SpecialChar ~
26523 global = 3;\SpecialChar ~
26548 \begin_inset LatexCommand \index{Copy propagation}
26604 Note: the dead stores created by this copy propagation will be eliminated
26605 by dead-code elimination.
26609 \begin_inset LatexCommand \index{Loop optimization}
26614 \begin_inset LatexCommand \label{sub:Loop-Optimizations}
26621 Two types of loop optimizations are done by SDCC
26629 of loop induction variables.
26630 In addition to the strength reduction the optimizer marks the induction
26631 variables and the register allocator tries to keep the induction variables
26632 in registers for the duration of the loop.
26633 Because of this preference of the register allocator
26634 \begin_inset LatexCommand \index{Register allocation}
26638 , loop induction optimization causes an increase in register pressure, which
26639 may cause unwanted spilling of other temporary variables into the stack
26640 \begin_inset LatexCommand \index{stack}
26645 The compiler will generate a warning message when it is forced to allocate
26646 extra space either on the stack or data space.
26647 If this extra space allocation is undesirable then induction optimization
26648 can be eliminated either for the entire source file (with -
26658 -noinduction option) or for a given function only using #pragma\SpecialChar ~
26660 \begin_inset LatexCommand \index{\#pragma noinduction}
26673 for (i = 0 ; i < 100 ; i ++)
26689 for (i = 0; i < 100; i++)
26698 As mentioned previously some loop invariants are not as apparent, all static
26699 address computations are also moved out of the loop.
26704 \begin_inset LatexCommand \index{Strength reduction}
26708 , this optimization substitutes an expression by a cheaper expression:
26713 for (i=0;i < 100; i++)
26731 for (i=0;i< 100;i++) {
26737 ar[itemp1] = itemp2;
26754 The more expensive multiplication
26755 \begin_inset LatexCommand \index{Multiplication}
26759 is changed to a less expensive addition.
26763 \begin_inset LatexCommand \index{Loop reversing}
26770 This optimization is done to reduce the overhead of checking loop boundaries
26771 for every iteration.
26772 Some simple loops can be reversed and implemented using a
26773 \begin_inset Quotes eld
26776 decrement and jump if not zero
26777 \begin_inset Quotes erd
26781 SDCC checks for the following criterion to determine if a loop is reversible
26782 (note: more sophisticated compilers use data-dependency analysis to make
26783 this determination, SDCC uses a more simple minded analysis).
26786 The 'for' loop is of the form
26792 for(<symbol> = <expression>; <sym> [< | <=] <expression>; [<sym>++ | <sym>
26802 The <for body> does not contain
26803 \begin_inset Quotes eld
26807 \begin_inset Quotes erd
26811 \begin_inset Quotes erd
26817 All goto's are contained within the loop.
26820 No function calls within the loop.
26823 The loop control variable <sym> is not assigned any value within the loop
26826 The loop control variable does NOT participate in any arithmetic operation
26830 There are NO switch statements in the loop.
26833 Algebraic Simplifications
26836 SDCC does numerous algebraic simplifications, the following is a small sub-set
26837 of these optimizations.
26842 i = j + 0;\SpecialChar ~
26846 /* changed to: */\SpecialChar ~
26852 i /= 2;\SpecialChar ~
26859 /* changed to: */\SpecialChar ~
26865 i = j - j;\SpecialChar ~
26869 /* changed to: */\SpecialChar ~
26875 i = j / 1;\SpecialChar ~
26879 /* changed to: */\SpecialChar ~
26886 Note the subexpressions
26887 \begin_inset LatexCommand \index{Subexpression}
26891 given above are generally introduced by macro expansions or as a result
26892 of copy/constant propagation.
26895 'switch' Statements
26896 \begin_inset LatexCommand \label{sub:'switch'-Statements}
26901 \begin_inset LatexCommand \index{switch statement}
26908 SDCC can optimize switch statements to jump tables
26909 \begin_inset LatexCommand \index{jump tables}
26914 It makes the decision based on an estimate of the generated code size.
26915 SDCC is quite liberal in the requirements for jump table generation:
26918 The labels need not be in order, and the starting number need not be one
26919 or zero, the case labels are in numerical sequence or not too many case
26920 labels are missing.
26926 switch(i) {\SpecialChar ~
26957 case 4: ...\SpecialChar ~
26989 case 5: ...\SpecialChar ~
27021 case 3: ...\SpecialChar ~
27052 case 6: ...\SpecialChar ~
27084 case 7: ...\SpecialChar ~
27116 case 8: ...\SpecialChar ~
27148 case 9: ...\SpecialChar ~
27180 case 10: ...\SpecialChar ~
27211 case 11: ...\SpecialChar ~
27278 Both the above switch statements will be implemented using a jump-table.
27279 The example to the right side is slightly more efficient as the check for
27280 the lower boundary of the jump-table is not needed.
27284 The number of case labels is not larger than supported by the target architectur
27288 If the case labels are not in numerical sequence ('gaps' between cases)
27289 SDCC checks whether a jump table with additionally inserted dummy cases
27290 is still attractive.
27294 If the starting number is not zero and a check for the lower boundary of
27295 the jump-table can thus be eliminated SDCC might insert dummy cases 0,
27300 Switch statements which have large gaps in the numeric sequence or those
27301 that have too many case labels can be split into more than one switch statement
27302 for efficient code generation, e.g.:
27382 If the above switch statement is broken down into two switch statements
27472 then both the switch statements will be implemented using jump-tables whereas
27473 the unmodified switch statement will not be.
27476 There might be reasons which SDCC cannot know about to either favour or
27477 not favour jump tables.
27478 If the target system has to be as quick for the last switch case as for
27479 the first (pro jump table), or if the switch argument is known to be zero
27480 in the majority of the cases (contra jump table).
27483 The pragma nojtbound
27484 \begin_inset LatexCommand \index{\#pragma nojtbound}
27488 can be used to turn off checking the
27501 It has no effect if a default label is supplied.
27502 Use of this pragma is dangerous: if the switch
27503 \begin_inset LatexCommand \index{switch statement}
27507 argument is not matched by a case statement the processor will happily
27511 Bit-shifting Operations
27512 \begin_inset LatexCommand \index{Bit shifting}
27519 Bit shifting is one of the most frequently used operation in embedded programmin
27521 SDCC tries to implement bit-shift operations in the most efficient way
27537 generates the following code:
27554 In general SDCC will never setup a loop if the shift count is known.
27597 \begin_inset LatexCommand \index{Bit rotation}
27604 A special case of the bit-shift operation is bit rotation
27605 \begin_inset LatexCommand \index{rotating bits}
27609 , SDCC recognizes the following expression to be a left bit-rotation:
27619 char i;\SpecialChar ~
27630 /* unsigned is needed for rotation */
27635 i = ((i << 1) | (i >> 7));
27644 will generate the following code:
27663 SDCC uses pattern matching on the parse tree to determine this operation.Variatio
27664 ns of this case will also be recognized as bit-rotation, i.e.:
27669 i = ((i >> 7) | (i << 1)); /* left-bit rotation */
27672 Nibble and Byte Swapping
27675 Other special cases of the bit-shift operations are nibble or byte swapping
27676 \begin_inset LatexCommand \index{swapping nibbles/bytes}
27680 , SDCC recognizes the following expressions:
27703 i = ((i << 4) | (i >> 4));
27709 j = ((j << 8) | (j >> 8));
27712 and generates a swap instruction for the nibble swapping
27713 \begin_inset LatexCommand \index{Nibble swapping}
27717 or move instructions for the byte swapping
27718 \begin_inset LatexCommand \index{Byte swapping}
27724 \begin_inset Quotes sld
27728 \begin_inset Quotes srd
27731 example can be used to convert from little to big-endian or vice versa.
27732 If you want to change the endianness of a
27736 integer you have to cast to
27743 Note that SDCC stores numbers in little-endian
27749 Usually 8-bit processors don't care much about endianness.
27750 This is not the case for the standard 8051 which only has an instruction
27756 \begin_inset LatexCommand \index{DPTR}
27764 so little-endian is the more efficient byte order.
27768 \begin_inset LatexCommand \index{little-endian}
27773 \begin_inset LatexCommand \index{Endianness}
27778 lowest order first).
27782 \begin_inset LatexCommand \index{Highest Order Bit}
27787 \begin_inset LatexCommand \index{Any Order Bit}
27794 It is frequently required to obtain the highest order bit of an integral
27795 type (long, int, short or char types).
27796 Also obtaining any other order bit is not uncommon.
27797 SDCC recognizes the following expressions to yield the highest order bit
27798 and generates optimized code for it, e.g.:
27811 unsigned char hob1, aob1;
27815 bit hob2, hob3, aob2, aob3;
27824 hob1 = (gint >> 15) & 1;
27828 hob2 = (gint >> 15) & 1;
27832 hob3 = gint & 0x8000;
27836 aob1 = (gint >> 9) & 1;
27840 aob2 = (gint >> 8) & 1;
27844 aob3 = gint & 0x0800;
27854 will generate the following code:
27887 000A E5*01\SpecialChar ~
27914 000C 23\SpecialChar ~
27945 000D 54 01\SpecialChar ~
27972 000F F5*02\SpecialChar ~
28027 0011 E5*01\SpecialChar ~
28054 0013 33\SpecialChar ~
28084 0014 92*00\SpecialChar ~
28139 0016 E5*01\SpecialChar ~
28166 0018 33\SpecialChar ~
28196 0019 92*01\SpecialChar ~
28251 001B E5*01\SpecialChar ~
28278 001D 03\SpecialChar ~
28309 001E 54 01\SpecialChar ~
28336 0020 F5*03\SpecialChar ~
28391 0022 E5*01\SpecialChar ~
28418 0024 13\SpecialChar ~
28448 0025 92*02\SpecialChar ~
28503 0027 E5*01\SpecialChar ~
28530 0029 A2 E3\SpecialChar ~
28557 002B 92*03\SpecialChar ~
28585 Other variations of these cases however will
28590 They are standard C expressions, so I heartily recommend these be the only
28591 way to get the highest order bit, (it is portable).
28592 Of course it will be recognized even if it is embedded in other expressions,
28598 xyz = gint + ((gint >> 15) & 1);
28601 will still be recognized.
28605 \begin_inset LatexCommand \index{Higher Order Byte}
28609 / Higher Order Word
28610 \begin_inset LatexCommand \index{Higher Order Word}
28617 It is also frequently required to obtain a higher order byte or word of
28618 a larger integral type (long, int or short types).
28619 SDCC recognizes the following expressions to yield the higher order byte
28620 or word and generates optimized code for it, e.g.:
28627 unsigned long int glong;
28635 unsigned char hob1, hob2;
28639 unsigned int how1, how2;
28648 hob1 = (gint >> 8) & 0xFF;
28652 hob2 = glong >> 24;
28656 how1 = (glong >> 16) & 0xFFFF;
28670 will generate the following code:
28703 0037 85*01*06\SpecialChar ~
28725 _foo_hob1_1_1,(_gint + 1)
28755 003A 85*05*07\SpecialChar ~
28777 _foo_hob2_1_1,(_glong + 3)
28807 003D 85*04*08\SpecialChar ~
28829 _foo_how1_1_1,(_glong + 2)
28831 0040 85*05*09\SpecialChar ~
28853 (_foo_how1_1_1 + 1),(_glong + 3)
28855 0043 85*03*0A\SpecialChar ~
28877 _foo_how2_1_1,(_glong + 1)
28879 0046 85*04*0B\SpecialChar ~
28901 (_foo_how2_1_1 + 1),(_glong + 2)
28904 Again, variations of these cases may
28909 They are standard C expressions, so I heartily recommend these be the only
28910 way to get the higher order byte/word, (it is portable).
28911 Of course it will be recognized even if it is embedded in other expressions,
28917 xyz = gint + ((gint >> 8) & 0xFF);
28920 will still be recognized.
28924 \begin_inset LatexCommand \label{sub:Peephole-Optimizer}
28929 \begin_inset LatexCommand \index{Peephole optimizer}
28936 The compiler uses a rule based, pattern matching and re-writing mechanism
28937 for peep-hole optimization.
28942 a peep-hole optimizer by Christopher W.
28943 Fraser (cwfraser\SpecialChar ~
28946 A default set of rules are compiled into the compiler, additional rules
28947 may be added with the
28960 \begin_inset LatexCommand \index{-\/-peep-file}
28967 The rule language is best illustrated with examples.
28991 The above rule will change the following assembly
28992 \begin_inset LatexCommand \index{Assembler routines}
29014 Note: All occurrences of a
29018 (pattern variable) must denote the same string.
29019 With the above rule, the assembly sequence:
29029 will remain unmodified.
29033 Other special case optimizations may be added by the user (via
29049 some variants of the 8051 MCU
29050 \begin_inset LatexCommand \index{MCS51 variants}
29063 The following two rules will change all
29082 replace { lcall %1 } by { acall %1 }
29084 replace { ljmp %1 } by { ajmp %1 }
29089 inline-assembler code
29091 is also passed through the peep hole optimizer, thus the peephole optimizer
29092 can also be used as an assembly level macro expander.
29093 The rules themselves are MCU dependent whereas the rule language infra-structur
29094 e is MCU independent.
29095 Peephole optimization rules for other MCU can be easily programmed using
29100 The syntax for a rule is as follows:
29105 rule := replace [ restart ] '{' <assembly sequence> '
29143 <assembly sequence> '
29161 '}' [if <functionName> ] '
29166 <assembly sequence> := assembly instruction (each instruction including
29167 labels must be on a separate line).
29171 The optimizer will apply to the rules one by one from the top in the sequence
29172 of their appearance, it will terminate when all rules are exhausted.
29173 If the 'restart' option is specified, then the optimizer will start matching
29174 the rules again from the top, this option for a rule is expensive (performance)
29175 , it is intended to be used in situations where a transformation will trigger
29176 the same rule again.
29177 An example of this (not a good one, it has side effects) is the following
29200 Note that the replace pattern cannot be a blank, but can be a comment line.
29201 Without the 'restart' option only the innermost 'pop' 'push' pair would
29202 be eliminated, i.e.:
29232 the restart option the rule will be applied again to the resulting code
29233 and then all the pop-push pairs will be eliminated to yield:
29243 A conditional function can be attached to a rule.
29244 Attaching rules are somewhat more involved, let me illustrate this with
29271 The optimizer does a look-up of a function name table defined in function
29276 in the source file SDCCpeeph.c, with the name
29281 If it finds a corresponding entry the function is called.
29282 Note there can be no parameters specified for these functions, in this
29287 is crucial, since the function
29291 expects to find the label in that particular variable (the hash table containin
29292 g the variable bindings is passed as a parameter).
29293 If you want to code more such functions, take a close look at the function
29294 labelInRange and the calling mechanism in source file SDCCpeeph.c.
29295 Currently implemented are
29297 labelInRange, labelRefCount, labelIsReturnOnly, operandsNotSame, xramMovcOption,
29298 24bitMode, portIsDS390, 24bitModeAndPortDS390
29307 I know this whole thing is a little kludgey, but maybe some day we will
29308 have some better means.
29309 If you are looking at this file, you will see the default rules that are
29310 compiled into the compiler, you can add your own rules in the default set
29311 there if you get tired of specifying the -
29325 \begin_inset LatexCommand \index{ANSI-compliance}
29330 \begin_inset LatexCommand \label{sub:ANSI-Compliance}
29337 The latest publically available version of the standard
29339 ISO/IEC 9899 - Programming languages - C
29341 should be available at:
29342 \begin_inset LatexCommand \url{http://www.open-std.org/jtc1/sc22/wg14/www/standards.html#9899}
29351 Deviations from the compliance:
29354 functions are not reentrant
29355 \begin_inset LatexCommand \index{reentrant}
29359 unless explicitly declared as such or the
29372 \begin_inset LatexCommand \index{-\/-stack-auto}
29378 command line option is specified.
29382 \begin_inset LatexCommand \index{struct}
29387 \begin_inset LatexCommand \index{union}
29391 cannot be assigned values directly, cannot be passed as function parameters
29392 or assigned to each other and cannot be a return value
29393 \begin_inset LatexCommand \index{return value}
29397 from a function, e.g.:
29423 s1 = s2 ; /* is invalid in SDCC although allowed in ANSI */
29442 s parms) /* invalid in SDCC although allowed in ANSI */
29463 return rets; /* is invalid in SDCC although allowed in ANSI */
29469 initialization of structure arrays must be fully braced.
29475 struct s { char x } a[] = {1, 2};\SpecialChar ~
29480 /* invalid in SDCC */
29482 struct s { char x } a[] = {{1}, {2}}; /* OK */
29487 \begin_inset LatexCommand \index{long long (not supported)}
29492 \begin_inset LatexCommand \index{int (64 bit) (not supported)}
29500 \begin_inset LatexCommand \index{double (not supported)}
29504 ' precision floating point
29505 \begin_inset LatexCommand \index{Floating point support}
29513 \begin_inset LatexCommand \index{K\&R style}
29517 function declarations are NOT allowed.
29523 foo(i,j) /* this old style of function declarations */
29525 int i,j; /* are valid in ANSI but not valid in SDCC */
29540 Most enhancements in C99 are not supported, f.e.:
29548 \begin_inset LatexCommand \index{inline (not supported)}
29554 int increment (int a) { return a+1; } /* is invalid in SDCC although allowed
29560 can be used as a work around */
29568 i=0; i<10; i++) /* is invalid in SDCC although allowed in C99 */
29572 Certain words that are valid identifiers in the standard may be reserved
29573 words in SDCC unless the
29586 \begin_inset LatexCommand \index{-\/-std-c89}
29601 \begin_inset LatexCommand \index{-\/-std-c99}
29607 command line options are used.
29608 These may include (depending on the selected processor): 'at', 'banked',
29609 'bit', 'code', 'critical', 'data', 'eeprom', 'far', 'flash', 'idata', 'interrup
29610 t', 'near', 'nonbanked', 'pdata', 'reentrant', 'sbit', 'sfr', 'shadowregs',
29611 'sram', 'using', 'wparam', 'xdata', '_overlay', '_asm', '_endasm', and
29613 Compliant equivalents of these keywords are always available in a form
29614 that begin with two underscores
29615 \begin_inset LatexCommand \index{\_\_ (prefix for extended keywords)}
29620 '__data' instead of 'data'.
29623 Cyclomatic Complexity
29624 \begin_inset LatexCommand \index{Cyclomatic complexity}
29631 Cyclomatic complexity of a function is defined as the number of independent
29632 paths the program can take during execution of the function.
29633 This is an important number since it defines the number test cases you
29634 have to generate to validate the function.
29635 The accepted industry standard for complexity number is 10, if the cyclomatic
29636 complexity reported by SDCC exceeds 10 you should think about simplification
29637 of the function logic.
29638 Note that the complexity level is not related to the number of lines of
29639 code in a function.
29640 Large functions can have low complexity, and small functions can have large
29646 SDCC uses the following formula to compute the complexity:
29651 complexity = (number of edges in control flow graph) - (number of nodes
29652 in control flow graph) + 2;
29656 Having said that the industry standard is 10, you should be aware that in
29657 some cases it be may unavoidable to have a complexity level of less than
29659 For example if you have switch statement with more than 10 case labels,
29660 each case label adds one to the complexity level.
29661 The complexity level is by no means an absolute measure of the algorithmic
29662 complexity of the function, it does however provide a good starting point
29663 for which functions you might look at for further optimization.
29666 Retargetting for other Processors
29669 The issues for retargetting the compiler are far too numerous to be covered
29671 What follows is a brief description of each of the seven phases of the
29672 compiler and its MCU dependency.
29675 Parsing the source and building the annotated parse tree.
29676 This phase is largely MCU independent (except for the language extensions).
29677 Syntax & semantic checks are also done in this phase, along with some initial
29678 optimizations like back patching labels and the pattern matching optimizations
29679 like bit-rotation etc.
29682 The second phase involves generating an intermediate code which can be easy
29683 manipulated during the later phases.
29684 This phase is entirely MCU independent.
29685 The intermediate code generation assumes the target machine has unlimited
29686 number of registers, and designates them with the name iTemp.
29687 The compiler can be made to dump a human readable form of the code generated
29701 This phase does the bulk of the standard optimizations and is also MCU independe
29703 This phase can be broken down into several sub-phases:
29707 Break down intermediate code (iCode) into basic blocks.
29709 Do control flow & data flow analysis on the basic blocks.
29711 Do local common subexpression elimination, then global subexpression elimination
29713 Dead code elimination
29717 If loop optimizations caused any changes then do 'global subexpression eliminati
29718 on' and 'dead code elimination' again.
29721 This phase determines the live-ranges; by live range I mean those iTemp
29722 variables defined by the compiler that still survive after all the optimization
29724 Live range analysis
29725 \begin_inset LatexCommand \index{Live range analysis}
29729 is essential for register allocation, since these computation determines
29730 which of these iTemps will be assigned to registers, and for how long.
29733 Phase five is register allocation.
29734 There are two parts to this process.
29738 The first part I call 'register packing' (for lack of a better term).
29739 In this case several MCU specific expression folding is done to reduce
29744 The second part is more MCU independent and deals with allocating registers
29745 to the remaining live ranges.
29746 A lot of MCU specific code does creep into this phase because of the limited
29747 number of index registers available in the 8051.
29750 The Code generation phase is (unhappily), entirely MCU dependent and very
29751 little (if any at all) of this code can be reused for other MCU.
29752 However the scheme for allocating a homogenized assembler operand for each
29753 iCode operand may be reused.
29756 As mentioned in the optimization section the peep-hole optimizer is rule
29757 based system, which can reprogrammed for other MCUs.
29760 More information is available in a wiki
29761 \begin_inset LatexCommand \index{wiki}
29766 \begin_inset LatexCommand \url{http://sdcc.sourceforge.net/release_wiki/index.php?page=SDCC+internals+and+porting}
29770 ) and in the thread
29771 \begin_inset LatexCommand \url{http://sf.net/mailarchive/message.php?msg_id=13954144}
29779 \begin_inset LatexCommand \index{Compiler internals}
29786 The anatomy of the compiler
29787 \begin_inset LatexCommand \label{sub:The-anatomy-of}
29796 This is an excerpt from an article published in Circuit Cellar Magazine
29802 It's a little outdated (the compiler is much more efficient now and user/develo
29803 per friendly), but pretty well exposes the guts of it all.
29809 The current version of SDCC can generate code for Intel 8051 and Z80 MCU.
29810 It is fairly easy to retarget for other 8-bit MCU.
29811 Here we take a look at some of the internals of the compiler.
29816 \begin_inset LatexCommand \index{Parsing}
29823 Parsing the input source file and creating an AST (Annotated Syntax Tree
29824 \begin_inset LatexCommand \index{Annotated syntax tree}
29829 This phase also involves propagating types (annotating each node of the
29830 parse tree with type information) and semantic analysis.
29831 There are some MCU specific parsing rules.
29832 For example the storage classes, the extended storage classes are MCU specific
29833 while there may be a xdata storage class for 8051 there is no such storage
29834 class for z80 or Atmel AVR.
29835 SDCC allows MCU specific storage class extensions, i.e.
29836 xdata will be treated as a storage class specifier when parsing 8051 C
29837 code but will be treated as a C identifier when parsing z80 or ATMEL AVR
29842 \begin_inset LatexCommand \index{iCode}
29849 Intermediate code generation.
29850 In this phase the AST is broken down into three-operand form (iCode).
29851 These three operand forms are represented as doubly linked lists.
29852 ICode is the term given to the intermediate form generated by the compiler.
29853 ICode example section shows some examples of iCode generated for some simple
29854 C source functions.
29858 \begin_inset LatexCommand \index{Optimizations}
29865 Bulk of the target independent optimizations is performed in this phase.
29866 The optimizations include constant propagation, common sub-expression eliminati
29867 on, loop invariant code movement, strength reduction of loop induction variables
29868 and dead-code elimination.
29871 Live range analysis
29872 \begin_inset LatexCommand \index{Live range analysis}
29879 During intermediate code generation phase, the compiler assumes the target
29880 machine has infinite number of registers and generates a lot of temporary
29882 The live range computation determines the lifetime of each of these compiler-ge
29883 nerated temporaries.
29884 A picture speaks a thousand words.
29885 ICode example sections show the live range annotations for each of the
29887 It is important to note here, each iCode is assigned a number in the order
29888 of its execution in the function.
29889 The live ranges are computed in terms of these numbers.
29890 The from number is the number of the iCode which first defines the operand
29891 and the to number signifies the iCode which uses this operand last.
29894 Register Allocation
29895 \begin_inset LatexCommand \index{Register allocation}
29902 The register allocation determines the type and number of registers needed
29904 In most MCUs only a few registers can be used for indirect addressing.
29905 In case of 8051 for example the registers R0 & R1 can be used to indirectly
29906 address the internal ram and DPTR to indirectly address the external ram.
29907 The compiler will try to allocate the appropriate register to pointer variables
29909 ICode example section shows the operands annotated with the registers assigned
29911 The compiler will try to keep operands in registers as much as possible;
29912 there are several schemes the compiler uses to do achieve this.
29913 When the compiler runs out of registers the compiler will check to see
29914 if there are any live operands which is not used or defined in the current
29915 basic block being processed, if there are any found then it will push that
29916 operand and use the registers in this block, the operand will then be popped
29917 at the end of the basic block.
29921 There are other MCU specific considerations in this phase.
29922 Some MCUs have an accumulator; very short-lived operands could be assigned
29923 to the accumulator instead of a general-purpose register.
29929 Figure II gives a table of iCode
29930 \begin_inset LatexCommand \index{iCode}
29934 operations supported by the compiler.
29935 The code generation involves translating these operations into corresponding
29936 assembly code for the processor.
29937 This sounds overly simple but that is the essence of code generation.
29938 Some of the iCode operations are generated on a MCU specific manner for
29939 example, the z80 port does not use registers to pass parameters so the
29940 SEND and RECV iCode operations will not be generated, and it also does
29941 not support JUMPTABLES.
29950 \begin_inset Tabular
29951 <lyxtabular version="3" rows="39" columns="4">
29952 <features islongtable="true" headBottomDL="true">
29953 <column alignment="block" valignment="top" leftline="true" width="13col%">
29954 <column alignment="left" valignment="top" leftline="true" width="13col%">
29955 <column alignment="block" valignment="top" leftline="true" width="22col%">
29956 <column alignment="block" valignment="top" leftline="true" rightline="true" width="40col%">
29957 <row topline="true" bottomline="true" endhead="true">
29958 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
29968 \begin_inset LatexCommand \index{iCode}
29975 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
29985 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
29995 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30006 <row topline="true">
30007 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30017 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30024 IC_LEFT() IC_RESULT()
30027 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30037 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30044 IC_RESULT = ! IC_LEFT;
30048 <row topline="true">
30049 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30059 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30066 IC_LEFT() IC_RESULT()
30069 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30076 Bitwise complement of
30079 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30086 IC_RESULT = ~IC_LEFT;
30090 <row topline="true">
30091 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30101 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30108 IC_LEFT() IC_RESULT()
30111 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30118 Rotate right with carry
30121 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30128 IC_RESULT = (IC_LEFT << 1) | (IC_LEFT >> (sizeof(IC_LEFT)*8-1));
30132 <row topline="true">
30133 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30143 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30150 IC_LEFT() IC_RESULT()
30153 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30160 Rotate left with carry
30163 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30170 IC_RESULT = (IC_LEFT << (sizeof(LC_LEFT)*8-1) ) | (IC_LEFT >> 1);
30174 <row topline="true">
30175 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30185 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30192 IC_LEFT() IC_RESULT()
30195 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30202 Get the highest order bit of IC_LEFT
30205 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30212 IC_RESULT = (IC_LEFT >> (sizeof(IC_LEFT)*8 -1));
30216 <row topline="true">
30217 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30227 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30234 IC_LEFT() IC_RESULT()
30237 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30247 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30254 IC_RESULT = - IC_LEFT;
30258 <row topline="true">
30259 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30269 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30279 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30286 Push the operand into stack
30289 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30300 <row topline="true">
30301 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30311 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30321 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30328 Pop the operand from the stack
30331 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30342 <row topline="true">
30343 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30353 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30360 IC_LEFT() IC_RESULT()
30363 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30370 Call the function represented by IC_LEFT
30373 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30380 IC_RESULT = IC_LEFT();
30384 <row topline="true">
30385 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30395 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30402 IC_LEFT() IC_RESULT()
30405 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30412 Call via function pointer
30415 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30422 IC_RESULT = (*IC_LEFT)();
30426 <row topline="true">
30427 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30437 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30447 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30454 Return the value in operand IC_LEFT
30457 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30468 <row topline="true">
30469 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30479 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30489 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30499 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30510 <row topline="true">
30511 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30521 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30531 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30541 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30552 <row topline="true">
30553 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30563 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30570 IC_LEFT() IC_RIGHT() IC_RESULT()
30573 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30583 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30590 IC_RESULT = IC_LEFT + IC_RIGHT
30594 <row topline="true">
30595 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30605 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30612 IC_LEFT() IC_RIGHT() IC_RESULT()
30615 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30625 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30632 IC_RESULT = IC_LEFT - IC_RIGHT
30636 <row topline="true">
30637 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30647 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30654 IC_LEFT() IC_RIGHT() IC_RESULT()
30657 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30667 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30674 IC_RESULT = IC_LEFT * IC_RIGHT;
30678 <row topline="true">
30679 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30689 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30696 IC_LEFT() IC_RIGHT() IC_RESULT()
30699 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30709 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30716 IC_RESULT = IC_LEFT / IC_RIGHT;
30720 <row topline="true">
30721 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30731 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30738 IC_LEFT() IC_RIGHT() IC_RESULT()
30741 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30751 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30758 IC_RESULT = IC_LEFT % IC_RIGHT;
30762 <row topline="true">
30763 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30773 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30780 IC_LEFT() IC_RIGHT() IC_RESULT()
30783 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30793 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30800 IC_RESULT = IC_LEFT < IC_RIGHT;
30804 <row topline="true">
30805 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30815 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30822 IC_LEFT() IC_RIGHT() IC_RESULT()
30825 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30835 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30842 IC_RESULT = IC_LEFT > IC_RIGHT;
30846 <row topline="true">
30847 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30857 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30864 IC_LEFT() IC_RIGHT() IC_RESULT()
30867 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30877 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30884 IC_RESULT = IC_LEFT == IC_RIGHT;
30888 <row topline="true">
30889 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30899 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30906 IC_LEFT() IC_RIGHT() IC_RESULT()
30909 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30916 Logical and operation
30919 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30926 IC_RESULT = IC_LEFT && IC_RIGHT;
30930 <row topline="true">
30931 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30941 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30948 IC_LEFT() IC_RIGHT() IC_RESULT()
30951 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30958 Logical or operation
30961 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
30968 IC_RESULT = IC_LEFT || IC_RIGHT;
30972 <row topline="true">
30973 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30983 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
30990 IC_LEFT() IC_RIGHT() IC_RESULT()
30993 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31003 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
31010 IC_RESULT = IC_LEFT ^ IC_RIGHT;
31014 <row topline="true">
31015 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31025 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31032 IC_LEFT() IC_RIGHT() IC_RESULT()
31035 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31045 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
31052 IC_RESULT = IC_LEFT | IC_RIGHT;
31056 <row topline="true">
31057 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31067 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31074 IC_LEFT() IC_RIGHT() IC_RESULT()
31077 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31087 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
31094 IC_RESULT = IC_LEFT & IC_RIGHT;
31098 <row topline="true">
31099 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31109 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31116 IC_LEFT() IC_RIGHT() IC_RESULT()
31119 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31129 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
31136 IC_RESULT = IC_LEFT << IC_RIGHT
31140 <row topline="true">
31141 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31151 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31158 IC_LEFT() IC_RIGHT() IC_RESULT()
31161 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31171 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
31178 IC_RESULT = IC_LEFT >> IC_RIGHT
31182 <row topline="true">
31183 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31195 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31202 IC_LEFT() IC_RESULT()
31205 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31215 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
31222 IC_RESULT = (*IC_LEFT);
31226 <row topline="true">
31227 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31237 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31244 IC_RIGHT() IC_RESULT()
31247 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31257 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
31264 (*IC_RESULT) = IC_RIGHT;
31268 <row topline="true">
31269 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31279 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31286 IC_RIGHT() IC_RESULT()
31289 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31299 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
31306 IC_RESULT = IC_RIGHT;
31310 <row topline="true">
31311 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31321 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31328 IC_COND IC_TRUE IC_LABEL
31331 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31339 If true label is present then jump to true label if condition is true else
31340 jump to false label if condition is false
31343 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
31350 if (IC_COND) goto IC_TRUE;
31356 If (!IC_COND) goto IC_FALSE;
31360 <row topline="true">
31361 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31371 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31378 IC_LEFT() IC_RESULT()
31381 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31391 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
31398 IC_RESULT = &IC_LEFT();
31402 <row topline="true">
31403 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31413 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31420 IC_JTCOND IC_JTLABELS
31423 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31430 Jump to list of labels depending on the value of JTCOND
31433 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
31444 <row topline="true">
31445 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31455 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31462 IC_RIGHT() IC_LEFT() IC_RESULT()
31465 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31475 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
31482 IC_RESULT = (typeof IC_LEFT) IC_RIGHT;
31486 <row topline="true">
31487 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31497 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31507 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31514 This is used for passing parameters in registers;
31516 move IC_LEFT to the next available parameter register.
31519 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
31530 <row topline="true">
31531 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31541 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31551 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31558 This is used for receiving parameters passed in registers;
31560 Move the values in the next parameter register to IC_RESULT
31563 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
31574 <row topline="true" bottomline="true">
31575 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31583 (some more have been added)
31586 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31593 <cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none">
31600 <cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none">
31626 In the original article Figure II was announced to be downloadable on
31631 ftp://ftp.circuitcellar.com/pub/Circuit_Cellar/2000/121/dutta.ZIP
31635 \begin_inset LatexCommand \index{iCode}
31642 This section shows some details of iCode.
31643 The example C code does not do anything useful; it is used as an example
31644 to illustrate the intermediate code generated by the compiler.
31656 /* This function does nothing useful.
31663 for the purpose of explaining iCode */
31666 short function (data int *x)
31674 short i=10; \SpecialChar ~
31676 /* dead initialization eliminated */
31681 short sum=10; /* dead initialization eliminated */
31694 while (*x) *x++ = *p++;
31708 /* compiler detects i,j to be induction variables */
31712 for (i = 0, j = 10 ; i < 10 ; i++, j
31738 mul += i * 3; \SpecialChar ~
31740 /* this multiplication remains */
31746 gint += j * 3;\SpecialChar ~
31748 /* this multiplication changed to addition */
31762 In addition to the operands each iCode contains information about the filename
31763 and line it corresponds to in the source file.
31764 The first field in the listing should be interpreted as follows:
31769 Filename(linenumber: iCode Execution sequence number : ICode hash table
31770 key : loop depth of the iCode).
31775 Then follows the human readable form of the ICode operation.
31776 Each operand of this triplet form can be of three basic types a) compiler
31777 generated temporary b) user defined variable c) a constant value.
31778 Note that local variables and parameters are replaced by compiler generated
31781 \begin_inset LatexCommand \index{Live range analysis}
31785 are computed only for temporaries (i.e.
31786 live ranges are not computed for global variables).
31788 \begin_inset LatexCommand \index{Register allocation}
31792 are allocated for temporaries only.
31793 Operands are formatted in the following manner:
31798 Operand Name [lr live-from : live-to ] { type information } [ registers
31804 As mentioned earlier the live ranges are computed in terms of the execution
31805 sequence number of the iCodes, for example
31807 the iTemp0 is live from (i.e.
31808 first defined in iCode with execution sequence number 3, and is last used
31809 in the iCode with sequence number 5).
31810 For induction variables such as iTemp21 the live range computation extends
31811 the lifetime from the start to the end of the loop.
31813 The register allocator used the live range information to allocate registers,
31814 the same registers may be used for different temporaries if their live
31815 ranges do not overlap, for example r0 is allocated to both iTemp6 and to
31816 iTemp17 since their live ranges do not overlap.
31817 In addition the allocator also takes into consideration the type and usage
31818 of a temporary, for example itemp6 is a pointer to near space and is used
31819 as to fetch data from (i.e.
31820 used in GET_VALUE_AT_ADDRESS) so it is allocated a pointer register (r0).
31821 Some short lived temporaries are allocated to special registers which have
31822 meaning to the code generator e.g.
31823 iTemp13 is allocated to a pseudo register CC which tells the back end that
31824 the temporary is used only for a conditional jump the code generation makes
31825 use of this information to optimize a compare and jump ICode.
31827 There are several loop optimizations
31828 \begin_inset LatexCommand \index{Loop optimization}
31832 performed by the compiler.
31833 It can detect induction variables iTemp21(i) and iTemp23(j).
31834 Also note the compiler does selective strength reduction
31835 \begin_inset LatexCommand \index{Strength reduction}
31840 the multiplication of an induction variable in line 18 (gint = j * 3) is
31841 changed to addition, a new temporary iTemp17 is allocated and assigned
31842 a initial value, a constant 3 is then added for each iteration of the loop.
31843 The compiler does not change the multiplication
31844 \begin_inset LatexCommand \index{Multiplication}
31848 in line 17 however since the processor does support an 8 * 8 bit multiplication.
31850 Note the dead code elimination
31851 \begin_inset LatexCommand \index{Dead-code elimination}
31855 optimization eliminated the dead assignments in line 7 & 8 to I and sum
31863 Sample.c (5:1:0:0) _entry($9) :
31868 Sample.c(5:2:1:0) proc _function [lr0:0]{function short}
31873 Sample.c(11:3:2:0) iTemp0 [lr3:5]{_near * int}[r2] = recv
31878 Sample.c(11:4:53:0) preHeaderLbl0($11) :
31883 Sample.c(11:5:55:0) iTemp6 [lr5:16]{_near * int}[r0] := iTemp0 [lr3:5]{_near
31889 Sample.c(11:6:5:1) _whilecontinue_0($1) :
31894 Sample.c(11:7:7:1) iTemp4 [lr7:8]{int}[r2 r3] = @[iTemp6 [lr5:16]{_near *
31900 Sample.c(11:8:8:1) if iTemp4 [lr7:8]{int}[r2 r3] == 0 goto _whilebreak_0($3)
31905 Sample.c(11:9:14:1) iTemp7 [lr9:13]{_far * int}[DPTR] := _p [lr0:0]{_far
31911 Sample.c(11:10:15:1) _p [lr0:0]{_far * int} = _p [lr0:0]{_far * int} + 0x2
31917 Sample.c(11:13:18:1) iTemp10 [lr13:14]{int}[r2 r3] = @[iTemp7 [lr9:13]{_far
31923 Sample.c(11:14:19:1) *(iTemp6 [lr5:16]{_near * int}[r0]) := iTemp10 [lr13:14]{int
31929 Sample.c(11:15:12:1) iTemp6 [lr5:16]{_near * int}[r0] = iTemp6 [lr5:16]{_near
31930 * int}[r0] + 0x2 {short}
31935 Sample.c(11:16:20:1) goto _whilecontinue_0($1)
31940 Sample.c(11:17:21:0)_whilebreak_0($3) :
31945 Sample.c(12:18:22:0) iTemp2 [lr18:40]{short}[r2] := 0x0 {short}
31950 Sample.c(13:19:23:0) iTemp11 [lr19:40]{short}[r3] := 0x0 {short}
31955 Sample.c(15:20:54:0)preHeaderLbl1($13) :
31960 Sample.c(15:21:56:0) iTemp21 [lr21:38]{short}[r4] := 0x0 {short}
31965 Sample.c(15:22:57:0) iTemp23 [lr22:38]{int}[r5 r6] := 0xa {int}
31970 Sample.c(15:23:58:0) iTemp17 [lr23:38]{int}[r7 r0] := 0x1e {int}
31975 Sample.c(15:24:26:1)_forcond_0($4) :
31980 Sample.c(15:25:27:1) iTemp13 [lr25:26]{char}[CC] = iTemp21 [lr21:38]{short}[r4]
31986 Sample.c(15:26:28:1) if iTemp13 [lr25:26]{char}[CC] == 0 goto _forbreak_0($7)
31991 Sample.c(16:27:31:1) iTemp2 [lr18:40]{short}[r2] = iTemp2 [lr18:40]{short}[r2]
31992 + ITemp21 [lr21:38]{short}[r4]
31997 Sample.c(17:29:33:1) iTemp15 [lr29:30]{short}[r1] = iTemp21 [lr21:38]{short}[r4]
32003 Sample.c(17:30:34:1) iTemp11 [lr19:40]{short}[r3] = iTemp11 [lr19:40]{short}[r3]
32004 + iTemp15 [lr29:30]{short}[r1]
32009 Sample.c(18:32:36:1:1) iTemp17 [lr23:38]{int}[r7 r0]= iTemp17 [lr23:38]{int}[r7
32015 Sample.c(18:33:37:1) _gint [lr0:0]{int} = _gint [lr0:0]{int} + iTemp17 [lr23:38]{
32021 Sample.c(15:36:42:1) iTemp21 [lr21:38]{short}[r4] = iTemp21 [lr21:38]{short}[r4]
32027 Sample.c(15:37:45:1) iTemp23 [lr22:38]{int}[r5 r6]= iTemp23 [lr22:38]{int}[r5
32033 Sample.c(19:38:47:1) goto _forcond_0($4)
32038 Sample.c(19:39:48:0)_forbreak_0($7) :
32043 Sample.c(20:40:49:0) iTemp24 [lr40:41]{short}[DPTR] = iTemp2 [lr18:40]{short}[r2]
32044 + ITemp11 [lr19:40]{short}[r3]
32049 Sample.c(20:41:50:0) ret iTemp24 [lr40:41]{short}
32054 Sample.c(20:42:51:0)_return($8) :
32059 Sample.c(20:43:52:0) eproc _function [lr0:0]{ ia0 re0 rm0}{function short}
32065 Finally the code generated for this function:
32106 ; ----------------------------------------------
32111 ; function function
32116 ; ----------------------------------------------
32126 ; iTemp0 [lr3:5]{_near * int}[r2] = recv
32138 ; iTemp6 [lr5:16]{_near * int}[r0] := iTemp0 [lr3:5]{_near * int}[r2]
32150 ;_whilecontinue_0($1) :
32160 ; iTemp4 [lr7:8]{int}[r2 r3] = @[iTemp6 [lr5:16]{_near * int}[r0]]
32165 ; if iTemp4 [lr7:8]{int}[r2 r3] == 0 goto _whilebreak_0($3)
32224 ; iTemp7 [lr9:13]{_far * int}[DPTR] := _p [lr0:0]{_far * int}
32243 ; _p [lr0:0]{_far * int} = _p [lr0:0]{_far * int} + 0x2 {short}
32290 ; iTemp10 [lr13:14]{int}[r2 r3] = @[iTemp7 [lr9:13]{_far * int}[DPTR]]
32330 ; *(iTemp6 [lr5:16]{_near * int}[r0]) := iTemp10 [lr13:14]{int}[r2 r3]
32356 ; iTemp6 [lr5:16]{_near * int}[r0] =
32361 ; iTemp6 [lr5:16]{_near * int}[r0] +
32378 ; goto _whilecontinue_0($1)
32390 ; _whilebreak_0($3) :
32400 ; iTemp2 [lr18:40]{short}[r2] := 0x0 {short}
32412 ; iTemp11 [lr19:40]{short}[r3] := 0x0 {short}
32424 ; iTemp21 [lr21:38]{short}[r4] := 0x0 {short}
32436 ; iTemp23 [lr22:38]{int}[r5 r6] := 0xa {int}
32455 ; iTemp17 [lr23:38]{int}[r7 r0] := 0x1e {int}
32484 ; iTemp13 [lr25:26]{char}[CC] = iTemp21 [lr21:38]{short}[r4] < 0xa {short}
32489 ; if iTemp13 [lr25:26]{char}[CC] == 0 goto _forbreak_0($7)
32534 ; iTemp2 [lr18:40]{short}[r2] = iTemp2 [lr18:40]{short}[r2] +
32539 ; iTemp21 [lr21:38]{short}[r4]
32565 ; iTemp15 [lr29:30]{short}[r1] = iTemp21 [lr21:38]{short}[r4] * 0x3 {short}
32598 ; iTemp11 [lr19:40]{short}[r3] = iTemp11 [lr19:40]{short}[r3] +
32603 ; iTemp15 [lr29:30]{short}[r1]
32622 ; iTemp17 [lr23:38]{int}[r7 r0]= iTemp17 [lr23:38]{int}[r7 r0]- 0x3 {short}
32669 ; _gint [lr0:0]{int} = _gint [lr0:0]{int} + iTemp17 [lr23:38]{int}[r7 r0]
32716 ; iTemp21 [lr21:38]{short}[r4] = iTemp21 [lr21:38]{short}[r4] + 0x1 {short}
32728 ; iTemp23 [lr22:38]{int}[r5 r6]= iTemp23 [lr22:38]{int}[r5 r6]- 0x1 {short}
32742 cjne r5,#0xff,00104$
32754 ; goto _forcond_0($4)
32766 ; _forbreak_0($7) :
32776 ; ret iTemp24 [lr40:41]{short}
32819 A few words about basic block successors, predecessors and dominators
32822 Successors are basic blocks
32823 \begin_inset LatexCommand \index{Basic blocks}
32827 that might execute after this basic block.
32829 Predecessors are basic blocks that might execute before reaching this basic
32832 Dominators are basic blocks that WILL execute before reaching this basic
32866 a) succList of [BB2] = [BB4], of [BB3] = [BB4], of [BB1] = [BB2,BB3]
32869 b) predList of [BB2] = [BB1], of [BB3] = [BB1], of [BB4] = [BB2,BB3]
32872 c) domVect of [BB4] = BB1 ...
32873 here we are not sure if BB2 or BB3 was executed but we are SURE that BB1
32881 \begin_inset LatexCommand \url{http://sdcc.sourceforge.net#Who}
32891 Thanks to all the other volunteer developers who have helped with coding,
32892 testing, web-page creation, distribution sets, etc.
32893 You know who you are :-)
32901 Also thanks to Sourceforge
32902 \begin_inset LatexCommand \url{http://www.sf.net}
32906 which has hosted the project since 1999 and donates significant download
32907 bandwidth and probably more than
32915 CPU cycles per day.
32923 more than 10^13 is an estimate: on my Athlon 2800+ it takes about (0.5+6.5+20)
32924 minutes for (configure+make+regression test), and there is (i386, amd64,
32925 alpha, ppc64, (mingw32), sparc, macosx).
32932 This document was initially written by Sandeep Dutta
32935 All product names mentioned herein may be trademarks
32936 \begin_inset LatexCommand \index{Trademarks}
32940 of their respective companies.
32947 To avoid confusion, the installation and building options for SDCC itself
32948 (chapter 2) are not part of the index.
32952 \begin_inset LatexCommand \printindex{}