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1. else leall test11 endif endif ifdef ifndef Usage ifdef SYMBOL and ifndef SYMBOL This directive simply checks if a SYMBOL is already defined It is quite similar to the if above An example If macro not already defined define it 1fndef char out macro char out No Ne Ne Se Ne mov A Q1 parameter 1 into A lcall output and OUT endmacro now the macro is definitely defined endif char out X Use the macro for output of a X hide show This two directives increment and decrement the documentation level of the assembler Only if this level is greater than zero a listing or sourcecode information is generated During expansion of a macro the level will be temporarily decremented So if you re interested in the expanded macros simply add an addition show The default level is 1 dc b de w dc l de f These directives insert numbers and strings in the output A comma is used as a delimiter For dc b strings may be used The byte order for dc w and dc l is Big Endian this means highbyte first The dc f inserts a number in the IEEE32 32 bit floating point format Some example 28 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual dc b Hello World 13 10 0 Text lt CR gt lt LF gt 0 dc w init 0000 AB AB is 41 542 same as dc b A B dc w test sppose test 8023 would be same as dc b 80 23 de l IinN1Et ABCD 4 byte constant SAGE2. endmacro sichern temp 17 17 bytes safe from sichern temp 10 10 Bytes safe from temp The label s0 in the both expansions is different 29 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual Generated symbols On demand if imported with import the assembler and the linker will generate additional symbols containing infos about segments The system let s be the segment s name so these additional labels are available a double at the beginning and end _ _org _ segment s start real address __ s_ size __ segment s real size in bytes bits for sclass bit _ s_maxsize __ maximum segment s size if supplied _ s load __ address of the initialisation data in the code space 1f supplied Wome wow Additionally for each sclass for s sclass can be text bit dram iram xram __ s_org _ __ s_size__ Last not least _ stack org _ the first unused byte in the internal RAM is used for the stack It will grow upwards _ bin size __ this is the complete size of the binary including all code and initialisation data Technical description of the related tools This chapter will work out some of the deeper details of the related tools It will follow in an later version of this documentation The libraries Currently only the most important library functions have been added But the list is continu ously growing standard libraries stdio h This is one of the most impor
3. line and a word about source level debugging o o oo o 2T macro endmacro 6 ee ee eee ete t ees 27 if else sendif 8 Si dedi RAN 28 del UMC Be te o A E Duh etry ale awa ag 28 DIE SIMO WW cis Li A A Sees On A E A E BO 28 dc b de w del def 56 9 6 56 cs a oS oh BE Be 28 lt ds b ds w ds l ds f 00000 ee ee eee ne tenes 29 MAGCIOS sk er ah ieee AS Oh oh tte ane dh ees alee tied dh ee ek hese 29 Generated symbols coito vsed ss iad ee PURSES PRES OSSD eae ese 30 Technical description of the related tools 30 The lbrarles ora usara da tie a Ne eas 30 Standard libraries 3 33 ia it Fok SRE A ARA 30 SCHON dt td Mere BEE 30 SOREN ID a ts Sota Pe ie te ba ace nae res la a ea 31 Cte es tae oe A Ma ais Ris Wi ee ae a a ee 32 A tas tk Abd ASO os ARON OS WOR MAES MAES AMO ge BO 32 A pe ask E eE eas oe A Ga fue Hi ee a 32 math o a a Lea ee 32 8051 SPECIES AA RA RARAS ATA 32 A E ee eer ate N A ee ee eee A 32 regs hy reg52 h reg535 h ic a A RE RG it ORAS 33 Appendix A Migrating from other compilers ___ 33 Memory usage memory models 0 0 cece eee eee 33 Absolute addresses A ak he a he eee ae i BO AEE AHR 33 Interrupts ec 6 63 55 9 5 oS erann Boa 8 oe BE GEOR a ARO OS Re ORS 33 Assembly language 0 ccc ete n en eas 33 Appendix B A demo of pC 51 s optimisers 34 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual HC 51 V1 10 User s Manual
4. Please note for uC 51 the memory model has no affect on where global variables are located unlike as in other compilers We suggest that you should use a typedef or a define to modify the memory type of global data depending on the memory model 8051 memory modifiers To distinguish between the different types of memory on the 8051 uC 51 defines some new keywords modifiers bit as unsigned char bit this data type uses only 1 bit Ideal for global flags The 8051 allows up to 128 bits for data 128 bits are reserved for Special Function Bits SFB Many of them have commonly used names like RI xdata data with this modifier is located in the external ram access to it needs a 16 Bit pointer code data is in the code memory access by a 16 Bit pointer near data is in the internal RAM locations 0 127 access by an 8 Bit pointer inear data is in the internal RAM locations 0 255 access by an 8 Bit pointer Using 10 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual inear is less effective than near because access is always done by an indirection It is well suited i e for global arrays in the internal RAM The advantage for inear is that it might be located in the upper half of the internal RAM whereas near and all local variables in the small memory model must be located in the lower half If the internal space is low on the controller consider the use of inear far or generic a far modifi
5. mended because it may disturb the optimiser which sometimes completely reorders the instructions of a function A good starting point is write a skeleton of your functions in C and use the compiler s output Our assembler syntax is slightly different from the standard we think that our syntax is better readable for information read the chapter about the assembler s technical reference Of course the differences concern only assembler directives and number representation the mnemonics are full compatible to the standard A few short hints for using the Assembler 51 continuous blocks of code should be placed in segments each segment starts with a segment NAME OPTIONST directive Segments of the same name will be joint by the linker The OPTIONS may be sclass SCLASS org 16 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual ORG size SIZE notext SCLASS is dram iram xram without SCLASS the segment is code ORG sets the segment to an absolute position the linker may add an additional offset due to it s rCODE XRAM parameter With SIZE the size of the segment will be fixed notext is only of use for data segments If notext is not set a mirror segment with initialisa tion data is added in the code segment this mechanism is used by the startup routine to initialise the data segments The labels of a segments can by exported with export or importet with import A more detailed descripti
6. FNAME is allowed error An optional text might follow this directive An error will be displayed and assembling is stopped Like 1f VERSION 1 error Only version 1 alloweed endif end Assembly is stopped All following text is ignored even if end is in an included file import Usage Import SYMBOL FURTHER_SYMBOLS Jopt To use a symbol defined in another sourcecode it must be imported otherwise the assem bler would give an error This is done by import export Usage export SYMBOL FURTHER_SYMBOLS op Exporting a symbol allows its global use If a symbol has import and export in the same sourcecode an export is assumed This is useful for libraries There is also the possibility to export assignments in uC 51 i e used for the startup_first function This might be useful i e for libraries I e If the IPC library would import the SDA and SCL pins and not define them by itself the user could write the following export SDA SCL SDA P1 7 SCL P1 6 26 WWW WICKENHAEUSER COM uC 51 V1 10 User s Manual This would set SDA and SCL only for this project to P1 6 7 Other pins could be used for other projects without changing the library Note If dealing with compiler generated symbols you must consider that the compiler will add a leading to each symbol So the function test in C correspondents to the symbol test in assembler file The directive file HL
7. Preface Thank you for deciding to use uC 51 a complete ANSI C language development system for the whole 8051 family of microcontrollers This is the documentation is for the first official release Although this is a version V1 xx using uC 51 bears no risk of jumping into cold water This development system has a long history the generated code is very stable and highly optimised Until now many industrial developments have been done with it The included source code libraries and demos cover a broad range from writing applications in full ANSI C for the smallest available 8051 CPUs ATMEL s 89C1051 with as little as 1kB of code space and only 64 bytes of internal RAM up to the largest uC 51 is able to manage memory sizes up to 16 MB from Maxim s 1 Wire Bus over the PC Bus up to Ethernet We developed uC 51 for our own use and needs Almost daily uC 51 is used by ourselves for all kind of industrial applications and these test beds are not easy Besides of that many useful functions arise like our PC Bus library or the binary safe function that locks a whole binary file against modifications History The idea for writing compilers was born a few years ago We had written a small BASIC compiler for use with 8051 based microcontroller Although this uBASIC 51 was quite simple writing software for the 8051 s suddenly became much easier than in Assembler But with the projects the demands grew too So the uC 5
8. a short jump could be used as an optimisation Therefore it uses a guess Most instructions are less than 2 bytes long so a label distance of 50 would allow short jumps within a distance of 50 assembler lines or 100 bytes which should be safe However increasing this value could improve code size If the assembler requires to decrease it please let us know UmShell amp Umake As introduced beforee these two helpers will build your software by using a recipe also named makefile UmShell is the graphical user interface but Umake will do all the work 20 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual The most important Flags in Make files The flags in the Make file are nothing more than variables able to hold a string value As there are C51FLAGS Flags for the compiler default is empty My be used for telling the compiler something like a definition CSIFLAGS dTEST dABC 3 is the same as if define TEST and define ABC 3 inside the source code ASIFLAGS Flags for the assembler predefined as d g d expand the macro _line for each sourceline needed for single step g include sourcecode info in the listing LSIFLAGS Flags for the linker predefined to r 8000 F000 this will link all programs to 8000 with xdata starting at F000 MODEL The memory model default is small set to large if required SIOTYPE The used library for the serial i o Default is d for using t
9. ccoo AAA a ROS Reentrant functions SAA AA ERE EES Indirect TUNCTIONS ds li BEER ds Varna dic functi ns 20 1264030 AAA AR AG ERO ERLE Integral promotion 0000 id A Oe Rabe Old style functions lt 2 cj asin xen ined aes IAS eke dee ah te Defining your own SFR s defining absolute addresses with Overwriting library functions 0 0 ccc nee The job Of Startup lt a ds ra ii The binary safe _bin_sSafe 20 0 ccc eens Efficient coding as0s seh tect hh AA One eae a Predefined Symbols 20 500 bine ibys eee es ar 19 Some important options command line pragma 19 UmShell 8 Umake eee 20 The most important Flags in Make files 21 Make tiles Simple i ash Sai aaa 21 Technical description of the compiler UC51 EXE _ _ sdi_ads 22 Technical description of the assembler A51 EXE __i_d 22 Mnemonics Luis a ste ae te ota o q aea oe ees 23 Names variables and labels o oooooocoo o 23 Numbers 3 cod ote tes a ao edad is veta tn ala 23 Operators oan oeie NS 24 Directives v hae reet werk de os fase cd tre gig has OS O ORRA A 24 SEO MENE ras ido de dr UA AA 24 Cd a o e e o A ie ed Ole ted AE ah ae 26 ADENT AN A E a EE A TN a 26 A O II A RA 26 O A O a Sade A ae amp Late wad Baha 26 AMD ORG 5g hea A wis ahaa ele Cale tt Bn Qe aa ds e nte 26 SOXDOUE AAA AS HU VRP AAA LY VES DOS OR TRV AEE 26 O A 27
10. decimal or for base 16 Make files simple This is a minimum description for make files The idea behind make is to have an recipe of how something is made from something else if the result is older than the sources in other words Make will only do what is really necessary Make is based on rules depending on file name extensions You may find the default rules in BIN BUILTINS MAK We have supplied rules for the most common tasks here in like 21 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual Making a bin out of c or s51 Making a obj out of c or s51 Making a bin out of obj and lib Making a hex out of bin Using a rule in a make file always starts with the result followed by a colon Then the sources follow To select a rule Make must detect the Target s filename in the sources i e happy bin fast obj happy obj newlink obj If any of the three sources are younger than happy bin Make will try to find a rule how to make happy bin It will detect that happy is in happy obj so 1t will use the rule for Making bin out of obj In case of success the file time stamps will reflect this Guess what the following line will do happy hex happy bin In some cases Make is not able to detect all dependencies 1 e if you change header files for a source code but Make does not know about this dependency it could be advised to watch for this but often one is too lazy to tell that In this ca
11. have been appropriate marked But we can not attest the accuracy of this information Use of a term should not be regarded as affecting the validity of any trademark or service mark Internet All references to Internet addresses are given by best knowledge However we want to emphasise particularly that the contents of those addresses usually are beyond our influence Therefor we dissociate us explicitly from any referenced contents if they are an offence against any current laws Installation and de installation uC 51 will work on any Win9x or better computer There is no special requirement This software may be completely removed by the computer s standard de installation routines Merely files which have been produced by the use of this software are excluded from de installation If desired remove them manually Important Please note that uC 51 must be installed in a path without whitespace charac ters i e C MyFiles uC51 but not C My Files uC51 because wC 51 s MAKE system is currently not able to handle such filenames Installing the full version If uC 51 is installed it will run first in the 8kb limited demo mode If you are owner of a license for the full version you first have to register your installation Each license gives your the right to install uC 51 on two 2 different computers provided that the software is only used on one computer at the same time From your vend
12. of the segment to its maximum size makes only sense in combination with parameter size Parameter notext Normally there is no way for the linker to initialise non code segments like RAM So the linker puts all initialisations data in a mirror segment This mirror segment might be accessed by the startup function to copy it to the RAM Parameter page NUMBER If this parameter is given the segment will be completely located inside a page of the given NUMBER As an example if the segment uses acall and ajmp instructions NUMBER must be 2048 A fixed value can be set for the segment parameter size Normally for NUMBER only powers of 2 are used Parameter align NUMBER This parameter specifies the condition for the first byte of the segment I e if a segment must start at an even address NUMBER must be 2 align and page might be used in any combination 25 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual include There are two versions include lt FILE gt and include FILE Both version include a text file in the assembly The difference is lt FILE gt uses the path given to the assembler by command line option i which points normally to wC 51 s include directory whereas FILE uses the directory relative to the current directory Included files may include further files bytes This directive will include a pure binary file i e a data table only the format ibytes
13. other case Include the header file bin_safe h to declare the function Due to the algorithm the speed is not very fast on a 12MHz 8051 about 8kB per sec can be examined Remark If one of our competitors has such a function too please let us know Efficient coding Keep in mind that the 8051 is a 8 Bit CPU whereas most books about C assume a 32 Bit bolt Unsigned operations usually are significantly faster than signed on the 8051 And the native data type for an 8051 is not int as for 16 Bit and 32 Bit CPUs but unsigned char Predefined symbols The compiler defines some preprocessor symbols which are common standard except for UC_ and 18051 _ DATE today s date __TIME and time _ FILE the name of the source file __LINE __ and the current line no _ STDC __ defined as _ STDC_ UC _ defined as UC __ this is uC 51 specific _ 18051 defined as 1 this is wC 51 specific only one leading Some important options command line pragma The compiler can be controlled either by command line or by pragma directives For the command line options the compiler will show a full list if called as UC51 Here the most 19 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual important options are described You can pass them to the compiler in a makefile by using the variable C51FLAGS 8 size speed a W dMACRO b0 nograph noline Debug level 1 default or 2 If
14. required the logger can send and receive calls and SMS The complete software required only about 15 kB of Code and about 60 Bytes of the internal RAM No external memory is needed Accessing the Internet requires to compile a TCP IP stack For wC 51 this is no problem the stack is finished as another reference application the appropriate hardware is available the board is match box sized and has a built in 10 MB Ethernet you may find more informa tion about the FlexGate family under WWW FLEXGATE COM The idea for the FlexGates was to have a module with a well known infrastructure on the one side and a true Web Server on the other side With only a very low overhead the user can access the application on the FlexGate with a standard Internet browser or by e mail But returning to the topics there is still a lot of room for further optimisation in uC 51 We will implement as much as possible Limitations of the demo version The demo version comes with only two restrictions the maximum size of the generated code is limited to 8 kB This is more than enough for real world applications 8 kB allows the use of floating point routines and printf functions In one of the demos shipped with uC 51 we have implemented a complete spectrum analysis in only about 6 kB The second restric tion is the demo version may only be used for educational or evaluation purposes WWW WICKENHAEUSER COM wC 51 V1 10 Use
15. result would be a constantly triggered watchdog reset To omit such things the user can specify a custom function It is called immediately after reset but internal RAM is already cleared and the stackpointer is set so it might be even written in C This tells the linker that a custom function must be called first asm export START DEF START DEF 1 endasm 18 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual The function itself The name is given void startup first void For the C515 our solution was to start a 60 msec interrupt delaying the watchdog to 16 sec Another idea is to jump directly to main if no initialisation of the external memory must be done The binary safe _bin_safe With this function a program can check it s integrity We have provided this function to lock binary files against modifications An example one of our customers distributes his binary updates for his machines by e mail the users can upload the update by themselves So there might be a chance that the one or other user tries to make changes in the binaries like text messages or something else But the software might still work bin_safe will detect such changes with a very high reliability Because it does not compute a simple checksum over itself it uses a 16 bit CRC instead which is quite hard to bypass bin safe will return 0 if no changes are found Decide for yourself what to to in the
16. 1 8 Version was developed Although the 8 Version s code generator was quite ineffective it was ideally suited for data logging applications where speed and software size usually is not crucial but where other things like floating point math and modular structured software are more important Still focusing on small devices we decided to embed the Internet in further developments For this a high efficient and optimising compiler was needed This was the trigger for the uC 51 V1 xx It comes with a totally new code generator generates a very high efficient code is easy to use and is full ANSI compatible with only a very few restrictions due to hardware limitations Target processors uC 51 is suited for all members of the 8051 family There are no special requirements like the need of external RAM We are using wC 51 on ATMEL s 89C1051 as well as on larger systems with banked memory like our FlexGate 512kB and or data loggers currently 2 MB Ready to start header files and source codes are included for many popular 8051 family members including some very interesting mixed signal parts like Ts MSC1210 and the ADuC8xx family from Analog Devices WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual Code quality uC 51 is based on a universal modelling system capable of modelling all kind of 8 16 32 bit processor cores But more important is that this system was especially designed to deal with non linear architectures
17. 322141997 25718282 two floating points ds b ds w ds l ds f Usage ds X NUMBER The ds X directives do nothing than simple reserve the number of bytes words longs or floats NUMBER must be a constant value or expression For the reserved space bytes of the vale 255 are written NUMBER might be zero In this case nothing is written Macros A macro is a simple text replacement with some additional features A macro may contain other macros and usage of temporary labels Before a macro can be used it has to be defined inside a macro endmacro block Each macro can have up to 10 arguments 0 to 9 The number of supplied arguments is given in 0 the first argument is in 1 If using an undefined argument an error will be generated Even complete strings might be used as macro arguments Please note during the expansion of a macro the documentation level is decremented see hide show Temporary labels are generated for each expansion An example macro help text help text in a table dc b 1 2 0 The system Help ID String 0 endmacro segment help tab sclass text help text 22 Valve open 7 usage help text 25 Temperature low another usage help text 17 C Copyright 2003 macro safe save register mov RO 1 a start mov R1 2 len 2s0 mov A RO not an argument instead a mnemonic inc RO next addr push ACC djnz R1 s0 7 s0 treated as ID s0 ID 1 2
18. AGS in the project s makefile UmShell to d listing only or to something else The default is AS1IFLAGS d g from BIN BUILTINS MAK Remark We are currently planning a new version of the SLD51 For a real breakpoint SLD51 will modify the jmp 0006 by something else possible because the program is located in the RAM This is not possible for Flash memory Because nowadays many 8051 s are equipped with Flash memory we will modify the breakpoint system to a non destructive system The new SLD51 will be able to debug on all 8051 s directly on the field used board Note The above mixing of assembly and sourcecode is quite simple Because the compiler sometimes totally reorders the logical flow of a function the output might not be 100 synchronise in some cases This is not an error it s just a matter of lazy cosmetics macro endmacro Usage macro NAME 27 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual The A51 is a macro assembler A macro is a simple text replacement with some additional features Programing with macros is described in the next part of this documentation Af else endif Usage if CONDITION This directives are use for conditional assembly The else part is an option The condition must be full evaluable at assembly time You can not use labels for the condition Conditions might be nested like if DEBUG LEVEL 1 1f SUBVERSION gt 2 lcall testl2p
19. L FILENAME tells the assembler that a high level language sourcefile currently only uC 51 corresponds to this assembler file Only one file directive is allowed in an assembler sourcefile line and a word about source level debugging The directive line NUMBER tells the assembler that all following mnemonics correspon dent to line no NUMBER of the sourcefile previously set by a file directive If the assem bler is instructed to produce a listing commandline s or to include high level sourcecode information in the object file commandline g the assembler will include the appropriate high level lines Otherwise nothing will happen But line has a second very important function It may be used to lard the binary file with breakpoints if the assembler is instructed to expand the macro _line by command line s d and a macro with the name _ line is called with NUMBER as an argument By default the uC 51 includes a definition for this macro as ljmp 0006 the argument NUMBER is currently not used At address 0006 there will be either the OS515 BIN or a simple ret instruction added by LIB LIB_C STARTUP C as a safety precaution So after each high level line C statement the monitor OS515 BIN is called This is a very nice feature for debugging software Unfortunately each breakpoint is three bytes of extra code and a little bit of time To disable this feature set either the definition ASIFL
20. OV R7 AR6 0022 7000055 0022 22 RET FUNCTION _bang END And this is the result of C 51 V1 10 we need only 25 bytes gt define Pl B6 0x86 gt define Pl B7 0x87 gt bit unsigned char out bit _P1_B6 gt bit unsigned char in bit _P1_B7 34 WWW WICKENHAEUSER COM uC 51 V1 10 User s Manual segment _ bang bang leaf function unsigned char bang unsigned char parameter ob in R7 assigned to R5 co 8007 ad 07 mov R5 AR7 Variable ib assigned to register Rl1 o gt Simple 8 Bit Banger gt unsigned char bang unsigned char ob co 8009 7b 08 mov R3 8 amp 238 gt int i gt unsigned char ib gt for 1 0 1 lt 8 1 co 800b ed mov A R5 co 800c 33 rlc A co 800d 92 86 mov 134 C gt out bit o0b8128 lt gt ib lt lt 1 co 800f e9 mov A R1 co 8010 29 add A R1 co 80l1 9 mov R1 A gt if in bit ib 1 co 8012 30 87 03 2 Jb 135 27 co 8015 43 01 01 orl AR1 1 I pE ob lt lt 1 co 8018 ed mov A R5 co 8019 2d add A R5 co 80la fd mov R5 A gt co 801b db ee E djnz R3 3 gt return ib co 801d af 01 mov R7 AR1 cosB01t 22 ret end of function bang used R 1 3 5 7 BR ACC PSW uC 51 s optimisers are still not fully implemented some parts are still completely missing The compiler is yet a learning child Many of the optimisers are founded on some kind of expert system As you might see the system is workin
21. WWW WICKENHAEUSER COM 110 51 V1 10 User s Manual mShell C C UC51 sre led led mak File Edit Search Options Window Help File Edit Search Make Options Help eu al Oe Mae 91 a Dle2 fiea bin gt bal if c c i Makefile for the LED Demo _pute va_arg ap int 0 1999 Wickenhaeuser len velse ific d Umake C C UCS1 bin cgS1l led x led s5l e A A pEdit UmShell Sid51 FlashiMon E CPU Registers f RO 38 ACC ff PC 803E inc DPTR RI 00 B 00 mov BRO A R2 20 E H 3 inc RO SP 3d DPTR 38888 djnz R1 _31 int i PSW a6 C 1 AC 0 RS 0 OV 1 P 0 for i 0 4 lt 20 i _pute a t ig3l 5 7 External Reset gt A co 8041 e4 Oco 8042 fc Hello World Aco 8043 fa Downloaded 2317 Bytes at 8000 ANSI C Compiler for the 8051 family of microcontrollers ol 1 oe ae een eee ee ae tee von eee weer eee Sree ees HISO ir N Gorter vai teehee test oot a eee aes Target p r cessors iii A hee keke eee A COde quality toi ra ds AA oes Aa Limitations of the demo version 0 0 00 c ccc eens Sourcecode compatibility with other compilers PUULVGISION toi 24 35 a oS oa eee eee een Be ha the Support Versions 5 33 LEIA Bh a BA AA PDOUL US AA OG gS Rs AA RE The TUU 002 dee Sova a a Se evs ae ains Disclaimer 2 A Gh Coats eae bas Betas hea ad EONS Soa ee sere ahs eae Pht AE a sae Sat ide Mates a an td A Se Tradem
22. addition to that Make uses Macros Think of them as variables By default some macros are predefined i e L51FLAGS may hold extra settings to be passed to the linker Back to the demo you may enter the rule above or simply open the prepared make file SRC HELLO HELLO MAK in UmShell Pressing lt F9 gt will generate the program It will have something about 300 bytes in size Now start the Soure Level Debugger SLD51 Select SRC HELLO HELLO BIN for download maybe you must select the appropriate baud rate for your board first if it is not 9600 Bd After downloading you may start by clicking on the shoe A The program will run in an endless loop printing Hello World You can single step through the assembler commands C files and set breakpoints with the mouse Note Currently there is no way to step over a breakpoint First disable it step over it then enable it again After a software stop through a breakpoint you need two assembler single steps just press lt F2 gt twice Because are simulated by an ljmp instruction written to the external RAM Because ljmp needs 3 Bytes it is not possible to set a breakpoint everywhere For the future we will revise the debugger totally that it even might be able to debug programs in Flash memory WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual Important Most of the demo makefiles will generate a pure binary file suitable to be wi
23. al Hex format lower case letters Single character Hex format upper case letters Floating point format form dddd dddd Scientific format form d dddd e ddd Scientific format form d dddd E ddd Same as e Same as g A string the itself a QMMOo xo o a As you see the formatter is quite complete The formatter will always return the number of written bytes number of calls of for the character handler Note for UART output each newline n is replaced by the sequence r n This is required for most terminal programs but our FLASHMON and SLD51 are inherent to this This is done directly by the character handlers of the serial I O see LIBILIB_ASSISERIOD S51 and LIB LIB_ASS SERIOP S51 So for the formatter each An counts only as one Remark There is no need of explicitly casting 8 bit sized values to 16 bit values This is automatically done by uC 51 as the ANSI standard requires The need of an explicit cast like other 8051 compilers need it is not according to the standard A word about strings in general Besides the alphanumeric and other printable characters you can designate hexadecimal and octal escape sequences in uC 51 These escape sequences are interpreted as ASCII characters allowing you to use characters outside the printable range ASCII decimal 20 126 The format of a hexadecimal escape sequence is ix lt hexnum gt where lt hexnum gt is up to 2 he
24. arks 0000 oh Blak A AAA RR Brie ies ta Sa Fi Seta ea Aah TAa A 243 A ohne ee ee daca ee Ae td AA sed Installation and de installation sn Installing the full version 94 5 4 ye6 aes pt A 24 CHEE A de te Wie ews 4 Documentation 0 0 0 ce ec ee eee eee ee eee eee e eee Quick start a micro tutorial ee Installati n nran ea a a TO TS RA OA a Microcontroller hardware special development boards Hello Worldi ts A A A AAA More about C the ANSI compatibility of wC 51 More demos tetas aa ee daha What s GOING ON 26 65 2054 22h cee A AAA ALA Basic data of pC 51 cece eens BUG reprit arca aio ale eww ten es e a be a Data LYPGS vir saw eee bake eal Oba eee Pes A eA ewe Mntesr ality pes IA ARES RGA WA AR EEA AAA Floating point precision 20 00 eee eens Pointer types 00 aed Me ad pe ad eee Se ES oe Memory models 2200 5 253 3 e tee AS AA eRe 8051 MEMOry MOdMIETS 0 cobras codes aa stan Understanding memory modifiers memory spaces and segmentation Memory modifiers in typedefs o oooo ocoooocoooocoo Register USO cuarta oud kee Ode we A Na Interr pts IN Ge Pai ES AA AAA A AS Dealing with call graphs oooo oocoocococr Using the printf formatter o oooooococcococcr o A word about strings in general 0 ccc eee eee nee Mixing C and Assembler o ooocccococo eee eens How to use assembler
25. c data of pC 51 Bug report If you think of having found a bug please let us know We will try as fast as possible to solve it Please include a small source to track the bug Please send bug reports only to UC51 WICKENHAEUSER DE Data types uC 51 is offers the following data types Integral types char 8 Bit 0 255 chars are treated as unsigned this is ANSI compatible unsigned char as above signed char 8 Bit 128 127 please note as a constant 128 is int ANSI short 16 Bit 32768 32767 please note as a constant 32768 is long ANSI int as above unsigned int 16 Bit 0 65535 long 32 Bit 214783648 2147483647 unsigned long 32 Bit 0 4294967295 float 32 Bit IEEE format char unsigned bit 1 Bit the modifier bit is no ANSI keyword all data is represented in the big endian format Data types not mentioned here are mapped to the next smaller types like double to float long long to long The data type bit is 8051 specific It has the values only 0 and non 0 the integral represen tation is 1 but the integral value 123 is seen as non 0 too Floating point precision The floating point routines are based on IEEE proceedings Rounding is performed as proposed All mathematical library functions like sin have been implemented by using industrial approved algorithms and approximations Pointer types generic far pointer 32 Bit explained later may point to everything xdata poi
26. cated in the code space but what about pc Well it is definitely not constant because pc can be written So uC 51 will spend a generic pointer in the xdata for it Even if you qualify it as const char const pc HELLO uC 51 will use a generic pointer although both in code because pc is a pointer and not an integral type For an explicit memory determination you may use the memory modifiers xdata int a a is xdata this is the dafault too near char u u is near access is fastest inear char x x is in the inear access is a little bit slower inear buf 50 if more internal memory is needed inear is the best choice unsigned char flag motor state On or off code float 3 12 23 3 45 5 99 a look up table 12 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual Memory modifiers for pointers follow the same rules as the ANSI const and volatile modifiers code char code pc HELLO This will fix pc as a bullet proof 16 Bit code pointer pointing to code xdata char near xp xp is in near but xp is xdata far char fp fp is in xdata default the far is obsolete but may be more readabl Summary Modifying the memory type in some situation will result in an optimised memory access uC 51 will track the modifiers over a random number of indirection s But don t exaggerate it the compiler will have the better overview than the user Memory modifiers
27. converting sourcecodes from other compilers concern non standard language extensions of these compilers Usually the uC 51 compiler will tell you what it does not like Some of the most important things you should know Memory usage memory models uC 51 offers only two memory models small this is the default and large The only difference between the two models is the type of memory for the local variables For small it is the internal RAM for large it is external RAM Non constant Global variables will always be placed in external RAM except something else is explicitly specified Globals might be placed in the internal RAM by the memory modifier near in the indirect internal RAM with inear Constant global variables are located in the code memory Bit variables are declared as unsigned char bit Absolute addresses Assigning an absolute address to a variable is done by the operator i e near unsigned char PO 0x80 After only a number a constant expression or a defined constant i e define SCL 0xB0 7 unsigned char bit scl_bit SCL is allowed Interrupts Interrupts might be written in uC 51 The vector is not included in the declaration binding an interrupt to a function requires the macro IRQ VECTOR as mentioned in the previous text Assembly language uC 51 s assembler uses other directives However mnemonics are full compatible to the 8051 standard Best way to conver
28. don t want to take an as close look at the internals don t worry The simple usage of uC 51 does not require this int a char pre name Bart const char last name Simpson void say hi char pc char pd printf Hello s s n pc pd void do_it void char no 1 no 0 0 say hi pre name last name say hi no King Kong a pre_name and last name are so called top level definitions They represent the data itself a and pre_name are global variables with read and write access uC 51 will place them in the external RAM xdata last name is declared as const The compiler knows that it might only be read later So it is safe to locate it in code the Code space some other compilers offer memory models that blindly pack everything in the external RAM only that they can later use single 16 Bit pointers what we think is an incredible waste of RAM see above 11 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual Same is for the String King Kong It is definitely a constant string so it will be placed in the code Code space too The no is local there is no choice for placement in the small model it will become a near in the large model it will become a xdata It is not top level too So pc and pd might point to anything in the 8051 s code space Because they are pointers and not bound to real data they are not top level This means the compiler can not automaticall
29. ed char _bin_safe void success return 0 math h All math functions have a precision of at least 7 significant digits All algorithms use indus trial approved iterations If you need a special mathematical function let us know Constants M PI 2 1 570796326794895 ANSI M PI 3 14159265358979 ANSI M TWO PI 6 28318530717958 Constant NOT ANSI Functions all according to the ANSI standard float atof far char pc convert a string to float float sqrt float f square root float sin float x sin function in radiants standard float cos float x cos float log float x natural logarithm float logl0 float x decimal logarithm float exp float x exponential function float pow float x power function 8051 specific irq52 h To bind an interrupt to an interrupt function irq52 h defines a macro name is the name of the function loc is either the address of the interrupts or its name like INTO SERIAL IRQ VECTOR name loc 32 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual reg51 h reg52 h reg535 h Header files for the most common CPUs other CPUs will follow The header files for very specific CPUs like the both mixed signal parts are located in the directory above their demos Appendix A Migrating from other compilers As stated before uC 51 was designed to be as close to the ANSI standard as possible on the 8051 That is why most items in
30. ed pointer may point to everything Currently far pointer are only virtual pointers You can not declare a variable as far this will be possible in future version In some cases the far keyword may be left out such pointers are called generic pointers the same is for local data types because there is no explicit modifier Understanding memory modifiers memory spaces and segmentation On common PCs there is no need for memory modifiers because all data can be accessed over a single usually 32 Bit pointer type the memory is flat A few years ago in the days of the good old 16 Bit PCs modifiers were quite common Even in some header files they still live on although without any effect For uC 51 we implemented modifiers as an option for the wise If you do not want to deal with memory modifiers just don t use them The price you have to pay is code size memory usage and speed An example the Dhrystone demo SRCIDHRYIDHRY C which is one of the standard demos of ancient times does not use them Nevertheless C 51 compiles it But if you let it run it will be quite slower than it could be Some competitors offer additional memory models which are better suited for such kind of source code but they usually are of limited practical use because they have other disadvantages and lesser portability For an explanation of memory modifiers let s start without them and look at the following code If you
31. escribe the logical hierarchy of a program Because each program begins with a main function main is always a root of the call graph After the call graph is built the linker knows about the used local space An example if main calls two functions a and b both may share the same local data if none of them calls each other In other situations they may only share parts of the data or none at all This informa tion is represented by the call graph 13 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual Call graphs can either be totally exclusive or identical Reasons for having more than one call graph in a program are interrupts or Assembler called C functions If the linker detects irregularities in the call graph it is not able to build the binary The depth of a call graph will represent the amount of used stack On the a 8051 each call takes 2 bytes so the depth of the call graph is about the same as the required stack space this is why each call takes two levels in the call graph Of course the compiler will at first try to use registers for parameters and variables Only if more space is needed local variables are allocated Using the printf formatter Formatted output is a too precious routine to waste it to a single printf implementation For this our printf simply calls a formatter function with its arguments and an additional output function By using this mechanism it is very easy to generate a
32. formatted output to almost everywhere One example is SRC RS232_2 RS232 C2 C where a function com2_printf is defined with only a few lines On our data loggers we use a flash_printf to write format ted messages to the Flash memory For our LC Displays a Icd_printf is supported For uC 51 s libraries the sprintf functions is based on this formatter You can find the complete source code of the formatter doprnt in the file LIBALIB_CIDOPRNT C Feel free to modify it The system is to pass a character handler the format string and the caller s arguments to the formatter Currently the printf formatter accepts formatting instructions of the type flags width prec 1 L type_char flags optional Left justifies the result pads on the right with blanks If not given it right justifies the result pads on the left with zeros or blanks Signed conversion results always begin with a plus or minus sign blank If value is nonnegative the output begins with a blank instead of a plus negative values still begin with a minus width optional Minimum number of characters to print padding with blanks or zeros prec optional Maximum number of characters to print for integers minimum number of digits to print L optional Treat the following type as 32 bit instead of 16 bit type_char u Unsigned format d Signed format 14 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manu
33. g but the collections of rules these expert systems are based on are still quite small and in other cases the results will not be as much as 40 better But C 51 has the ability to do it and we have first V1 10 yet END 35
34. he interrupt driven one In some cases a polled version might fit better the polled version gets all possible values 0 255 and is smaller in size but the interrupt driven version allows source code debugging Set to p to use the polled version PFLAGS If set to PFLAGS FULL_ PRINTF the full featured printf formatter ist used This might be interesting if format strings are dynamically generated during execution By default the value is SMART PRINTF which allow the compiler to tailor the formatter to the minimum size The default definitions for the macros above are found in BINBUILTINS MAK If you want to get help about additional parameters you can start the program Assembler Compiler Linker from command line with the parameter One of the most important items is ASIFLAGS d Usually the compiler writes a defini tion for the macro __line at the beginning of each translated file Currently this macro does nothing else than make a call to location 0006 where the debugger is expected The assem bler then will expand this macro for each C source line in its output so you can single step through your program But if the software development is finished you should disable this feature because for each line 3 bytes are spend if you forget it this is not crucial because there is a default handler so your software won t crash The format of the numbers in the L51FLAGS can be either 0x
35. he supplement About us Wickenh user Elektrotechnik is a small company located in the southern part of Germany This is our address Wickenh user Elektrotechnik Nikolaus Lenau Str 20 D 76199 Karlsruhe Germany Phone 49 0 721 98849 0 Fax 49 0 721 98849 29 E mail SERVICE WICKENHAEUSER DE for administrative contacts only UC51 WICKENHAEUSER DE for wC 51 related correspondence The future There are lots of improvements optimisations tools demos on our list One is the Graphical User Interface for wC 51 Although the included one is quite sufficient putting it all under one IDE might be a little more convenient Additionally we want to expand the FlexGate family by some members and port the uC to other cores 3 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual Disclaimer If you disagree in any of the following items installation and use of this software is not permitted Errors Our software and hardware has been carefully developed and tested But it is a well known fact that at the contemporary state of technology it is not possible to guarantee that a product is completely free of errors For that reason we decline any liability loss or damage caused directly or indirectly by our software and or use of our hardware The use is at your own risk Trademarks All terms mentioned in this software and the complementary documentation that are known to be trademarks or service marks
36. ike puts except it does not add the new line char at the end The inputse can be used to retrieve a input from the user to the string where pc points to of size max The result is the length of the user s input at maximum this is max 1 The string has a 0 char at the end void putsl far char ps Non Standard unsigned char inputse far char pc unsigned char max Non Standard Remark inputse is used in the demo SRC MINI535 M535V3 C string h A few ANSI standard string functions int strlen far char px int strcmp far char pa far char pb int memcmp far char pa far char pb int n far char strcpy far char pdst far char psrc A non ANSI byte move note src is the first argument But also quite common void bmove far void psrc far void pdest unsigned int count Remark all memory move functions use generic pointer so memory can be moved from and to everywhere If the memory type of the source and destination is known i e both external RAM a more specific move function could run very much faster We will supply these in the next version of uC 51 31 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual ctype h char tolower char c char toupper char c stdarg h Defines ANSI compatible access to variadic arguments va_start y y va_arg x y va end x bin_safe h This file declares only one function for the binary safe as stated before unsign
37. in typedefs This is not recommended There is no situation where a memory modifier can not be put outside a typedef Register usage On the 8051 we have 4 register banks By default uC 51 uses the lower two banks 0 and 1 If not desired as it might be for interrupt functions the compiler can be instructed only to use bank 0 An example for this can be found in SRC MISC SOFT_RTC C Bank 2 and 3 are completely free We suggest to reserve them for debuggers protocol stacks and other background stuff Of course they can be used as regular space in the near memory But currently the linker can not do this automatically because it can not locate near segments below the bit segment For this the easiest way is to partition those at maximum 16 Bytes manually i e near char buf a 8 16 near char buf b 8 24 This will reserve two buffers in the bank 2 and 3 area the directive is described later Interrupts in C Interrupts may be written in C uC 51 is keeping a list of the trashed registers during a function and will only save the trashed registers To declare a function an interrupts function the interrupt keyword must be added after the declaration The function must have a proto type To assign the function to an interrupts the macro IRQ_VECTOR function cpu_irqad dress from lt irq52 h gt is needed See SRC MISC SOFT_RTC C as an example Dealing with call graphs Call graphs are graphs which d
38. ined in an include file As a convention all of the 8051 s SFRs are upper case letters In cases where a number is expected you may even use a calculation like simply writing mov R6 a you could write could be useful in macros use braces WORKREG 5 mov R WORKREG 1 a Names variables and labels All names must be composed as in C first char a z or A Z rest may contain numbers A name must not exceed 64 characters else this will lead to an error message Labels have a following colon and are treated as addresses A variable is a symbol that can hold a value assignment Multiple assignments for the same symbol are allowed nr 11 mov A nr nr is 11 nr 21 mov A 21 gt nr is 21 Temporary labels may have a as first sign Temporary labels behave like normal labels except they will never appear in a listing Numbers The assembler will accept many different formats 123 regular decimal number x 8 bit number ASCII character AB 16 bit number like ASCII character A 256 B 0x100 Hex number 256 dec C language syntax 100 Hex number 256 dec Motorola syntax 0100h Hex number 256 dec Intel syntax version 1 0100H Hex number 256 dec Intel syntax version 1 100h Hex number 256 dec Intel syntax version 2 100H Hex number 256 dec Intel syntax version 2 0100 Octal base 8 number 83 dec C language syntax 23 WWW WICKENHAEUSER COM wC 51 V1 10 User s Ma
39. like the 8051 s Harvard architecture with separated code and data space uC 51 is the first implementation for this system and the results are very good There is only a very small part in the software especially dedicated to the 8051 but the generated code can easily compete with the market leaders as they describe themselves In some cases the code is even better i e 1C 51 V1 10 translates the SIEVE demo SRC SIEVE SIEVE C which is one of the standard demos with a module size of 142 bytes the closest competitor needs 6 more the total code size is only 897 bytes no one of the market leaders does beat this Read more about uC 51 s optimisation techniques and a comparison with other compilers in the appendix of this documentation If demanded like here the compiler utilises a call graph scheme for minimum usage of the precious resources for the 8051 this is undoubted the internal RAM In combination with a data flow optimisation the amount of allocated internal RAM is astonishing low Before publishing uC 51 V1 xx we have implemented for customers and as a test suite many reference applications One was a data logger controlling a RS485 network of remote sensor nodes The logger has a built in a cellular GSM modem 2MB Flash memory for program and data only 256 Bytes of internal RAM and a Real Time Clock For minimum power the modem is hooked to the cellular net only for short times If
40. ment This segment is cleared by startup On demand the linker will generate additional symbols allowing access to internal data of the segments like size load address This feature is normally not used Note The linker will remove all unused segments only referenced segments of segments containing an org parameter will be linked to the binary Parameter org NUMBER 24 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual Sets an absolute address for this segment Only once per segment allowed The program will start with the first label of the segment with org 0000 This value might be added by and offset from the linker like for our development boards The linker offset is set to 8000 by default where the RAM starts and the program will be downloaded to Parameter sclass NAME Sets the memory class of the segment If no sclass is given the default sclass is text Allowed NAMEs for the 8051 text Code constants EPROM This is also the default storage class xram The external RAM bit The bit field in the internal RAM from 20 2F dram The internal direct accessible RAM from 0 7F dram The internal indirect accessible RAM from 0 FF Parameter size NUMBER Defines the maximum size for this segment For multiple set size only the largest directive is used The compiler makes intensive use of this directive to manage local variables Parameter fill If set the linker will always set the size
41. ntegral promotion The ANSI standard defines the integral promotion It says that all calculations smaller than int are extended to int size and float to double On a 8 Bit microcontroller this will produce a huge overhead of code You can enable the integral promotion for uC 51 too by default it is disabled uC 51 uses a smart promotion scheme it will only extend the size of a result if it is required For functions integral promotion is omitted if a prototype for the function is given 17 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual Old style functions They may be used in the common old way but all arguments are automatically treated by integral promotion even if there is a prototype following Mixing old style and new style declarations in different files may lead to undesired results Defining your own SFR s defining absolute addresses with One of the reasons for the success of the 8051 family is that new family members simply have more or other special function registers SFR To use a special family member we have supplied some register definition files like INCLUDE REGS51 H or REG52 H or REGS35 H To extend or modify the given definition files there are two ways The first way might be used if it is important to have the definition for assembler as well as for C First add the definition for Assembler like WPM_BIT P3 4 Then in a second line this definition must be mapped t
42. nter 16 Bit external ram code pointer 16 Bit code memory WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual near pointer 8 Bit internal RAM address 0 127 inear pointer 8 Bit internal RAM address 0 255 bit pointer not an allowed type Memory models uC 51 supports two memory models small and large in the small model all local variables are located in the internal RAM near This is the fastest model Unfortunately there are only 128 Bytes If large blocks must be allocated as local variables the large model must be used Currently it is not possible to mix both models in one application Both memory models use the call graph scheme for minimum RAM usage The type of the memory which is used for the local variables and parameters is the only difference for the two memory models Global variables can be placed in both models anywhere By default if nothing else is specified they will be placed in the external RAM or in the code area if it is a constant But if using the memory modifies xdata code near inear and bit each variable can separately been placed anywhere you like Of course generic pointers can address the whole 256 16 MB address space in both models The names small and large denote only the size of the available memory for the local variables Nothing else By default the compilers chooses the small model To use the large model the flag C51FLAGS must be set to CSIFLAGS large in UmShell
43. nual 111 Binary number 7 dec 000111 Binary number 7 dec 0111b Binary number 7 dec Intel syntax version 1 0111B Binary number 7 dec Intel syntax version 1 111b Binary number 7 dec Intel syntax version 2 111b Binary number 7 dec Intel syntax version 2 We recommend the formats with and They are the most readable ones Operators The A51 uses the same operators and hierarchy as C except bit addressing Braces highest Priority 4 Bit addressing like ACC 7 highest bit of ACC Multiplication division module As sign lt lt gt gt Shift operators lt gt gt lt Comparison value is 1 if true 0 for false amp Binary and di Binary exclusive or Binary or amp amp Logical and Il Logical or Directives segment Usage segment NAME Parameter Jopi Open an existing or a new segment NAME The linker will collect all segments with the same NAME and treat them as an unit The compiler will generate a segment for each C function We recommend to use as NAME the name of the function or entry label plus a leading For functions each function should have its own segment for the code whereas for data of the same type only one segment should be used The names for the data segments are given and so the startup function can initialise them properly the IRQ driven serial I O driver LIB _ASS SERIOD S51 uses this technique to declare a byte variable in the nearbss seg
44. o the appropriate C symbol because C adds an WPM_BIT WPM BIT In the last step the new symbol must have a declaration for the compiler extern unsigned char bit WPM_BIT The Second way is more easy but it declares the new symbol only for C use simply add the definition to the declaration unsigned char WPM_BIT 0x85 That s all Overwriting library functions You may overwrite C library functions those with a as first character For instance if you think you have a better sin function than ours simply add your own as an OBJ file to your program Symbols in objects files always have a higher priority than library symbols If you overwrite an assembler symbol the linker will use your definition but it will present you a warning which you might ignore The job of startup The startup function is responsible for the initialisation of the microcontroller s stack and all types of RAM and even Bits All variable spaces are either set to 0 or initialised by their initial values You may customise the startup function to perform some extra work find it in LIBILIB_CV it is not a real C function but it requires the C preprocessor Sometimes the user might be interested to run one specific routine before doing all the initial ising One example is the C515 s impacient watchdog It has a timeout of only 65 msec But if there is a lot of data to initialise it might take longer than this period The
45. omplementary documentation is available as separate files Please read the documenta tion carefully prior to the use of the software You will find the latest remarks in the file README TXT Quick start a micro tutorial Installation uC 51 will work on any Win9x or better computer There is no special requirement For installation simply follow the advices again wC 51 does not make any hidden changes on the installed computer like copying DLLs to the system directories or writing unsolicited entries in the registry You can remove it 100 Important Please note that uC 51 must be installed in a path without whitespace charac ters i e C MyFiles uC51 but not C My Files uC51 because wC 51 s MAKE system is currently not able to handle such filenames WWW WICKENHAEUSER COM uC 51 V1 10 User s Manual Microcontroller hardware special development boards As stated before uC 51 is a development system for all 8051 family members But for devel oping and testing a convenient way is to use a special board where you can download and run binary files in an external RAM Of course there are alternatives like using an emula tor or doing a pure software simulation decide this for your own Later if the program or the tested functions are running as expected they might be directly used on or programmed to the dedicated target system Note We recommend to use such a
46. on for the assembler is in a later chapter Reentrant functions Reentrant functions are seldom required To learn more about them see MISCFACULTY C There is only one special case where reentrant functions are really required this is when a function is called indirect as well as direct like putc it may be used direct to send single chars to the UART but it is also used as a parameter for the printf formatter which calls it indirect Our advice is don t care about reentrant functions unless the linker explicitly tells you to use them On the 8051 reentrant functions are not allowed to have variable argument lists The execution speed of reentrant functions is somewhat slower than non reentrant ones if there are local arguments to be saved because all reentrant functions share one memory space for local variables and passed non register arguments Indirect functions Indirect functions may be used in the common manner there is only one limitation indirect functions are limited to 6 Bytes for arguments All indirect functions will become a root of a call graph so the linker will not share memory for local variables between them Variadic functions Functions with variable argument lists are common C standard like printf Variadic functions must have a prototye There is one special exception for arguments variadic arguments are always promoted to integrals You need to consider this to access them later I
47. or you will get a 12 digit code that we will named Key1 here WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual Registering uC 51 is a two step process 1 First you must start KEY51 EXE If a valid license is found for this computer the data will be displayed else you must enter the Keyl With this information KEY51 EXE will collect some computer specific data and generate a new key which has 20 digits Key2 This Key2 must be sent to us by e mail where it is processed by a machine in short intervals a few minutes If you cannot send e mails from this computer you must send us the Key2 manually as an e mail 2 If everything is ok you will receive a license file with the name UC51 KEY as a reply You must copy this file into the BIN file of your uC 51 installation After that program KEY51 EXE should find a valid license if started again Your privacy is not touched The Key2 contains only hardware specific information with a strong redundancy you may change quite a lot of system components before the license file won t be recognised as valid any more If you request more than two license files you can only order them manually by e mail to serviceQwickenhaeuser de and we might ask you for the reason We have ensured by independent trustees that uC 51 can be always distributed maintained and licensed no matter what will happen Documentation The c
48. r s Manual uC 51 does not make any hidden changes on the installed computer like copying DLLs to the system directories or writing unsolicited entries in the registry You can remove it 100 if using the included uninstaller Sourcecode compatibility with other compilers uC 51 is a full ANSI C compiler So it will accept any ANSI C compliant sourecode with only a very few 8051 specific restrictions However due to the limitations of the 8051 each manufacturer has made specific extensions to his implementation One of our most important design topics was to make wC 51 an highly portable and easy to use compiler and not yet another clone of any other very specific implementation But in most cases sourcecodes from other 8051 compilers can be compiled without any problems if only a few items are regarded More information about using sourcecodes from other compilers with uC 51 can be found in the appendix and in the included demos Full version The full version is offered through our web shop and through different distributors Please visit our website for detailed information Support Versions A license for uC 51 is valid for all minor releases of this version here V1 You can download new releases for free from our website Questions about the actual release should be sent to UC51 WICKENHAEUSER DE Support is only possible by e mail You will find a list of improvements changes of new version gt V1 10 in t
49. se you can tell Make to rebuilt the whole project without regarding the dependencies The place where a macro is defined is not important because first the make file is totally read It is allowed to overwrite macros or to use other macros as parameters in brackets with a leading A simple is replaced by the filename of the destination without file exten sion a lt is replaced by all dependencies for UmShell this is lt F8 gt It is possible to supply an own rule for a dependency In this case a default rule will be ignored if there is one An example for this may be found in LIB LIB_ALL MAK In a future version we will support UmShell with some kind of Expert Technical description of the compiler UC51 EXE This chapter will work out some of the deeper details of the compiler It will follow in an later version of this documentation Technical description of the assembler A51 EXE The A51 is a macro assembler It was designed as a reliable and stable workhorse and as for the compiler the A51 is almost totally independent from the 8051 too A51 operates as a single pass assembler Thus making it very fast 22 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual Mnemonics The syntax uses the common standard Mnemonics and is sensitive Mnemonics itself are not case sensitive but any used symbols you may write mov a 0 or mov a 0 or mov ACC 0 but not mov acc 0 because ACC is a symbol def
50. set to 2 the compiler will include more source info in the output but the code might be less optimised Optimise for size this is the default Optimise for speed Suppress strict warnings Suppress all warnings Define a Macro to assign a value use dMACRO VALUE Use only register bank 0 by default 0 and 1 will be used Disable the call graph Will need a lot of RAM Don t emit code for the macro _line You can supply an own version for this macro see Technical description of the assembler Some parameters are also available as pragma s pragma option gX Set debug level X 1 or 2 Fpragma option a Suppress strict warnings pragma option a Enable strict warnings pragma option w Suppress all warnings pragma option w Enable all warnings pragma cpu b0 Use only register bank 0 pragma cpu b0 Use register bank 0 and 1 pragma cpu noline Don t emit line directives pragma cpu noline Emit line directives pragma cpu nograph Don t emit call graph information pragma cpu nograph Emit call graph information pragma cpu large Switch to large memory model pragma cpu small Switch to small memory model pragma cpu labeldist X Set new label distance for short jumps pragma cpu labeldist Restore default label distance The label distance is a number currently set to 50 as default Because uC 51 has no internal assembler it does not know if
51. special development board for developing functions and algorithms in the RAM Finally you may use them on the intended boards where debugging might be more difficult Alternative Some of our boards like the FlexGate offer two different memory models memory model one allows download to RAM like the following picture memory model two offers several different 64kB banks of Flash memory for the code the RAM is totally free for data Switching between the two memory models is handled by our 0S535 BIN together in combination with a programmable logic chip That s why they are best suited for development and field use Here we assume that you use a board with the following hardware structure like our MINI535 FLASH M1 FlexGate where you can download the binary files with the included tools FLAsHMoN M and or sLDS1 gt dd gt SFFFF Code amp Data joint tog 8000 as XRAM for download S7FFF fe OS535 BIN 0000 p Eprom Data Code The CPU should be a 80C535 C515 8051 compatible or a generic 8051 Most of the demos require a 11 0592 to 12 0 MHz crystal If you have an 80C535 or an C515 with 12 0 MHz you can start immediately Burn the file SRC OS OS535 BIN to an Eprom format is binary For other commonly used CPUs or crystals the OS535 BIN supports a switch but nevertheless it must be rebuilt as shown below The board must have a serial port RS232 If your hardware does ha
52. sy All parameters are passed in bank 0 There are 4 groups of each 2 Bytes sstarting from R7 R6 L H to R1 2 L H Allocation is done left to right where R7 is the first If 1 Par is a Byte it is in R7 if it is 2 Bytes it is in R6 R7 H L The next Parameter will allocate R5 or R4 R5 H L If a parameter has 4 Bytes it will allocate either R4 R7 HH LL if it is free or R3 RO Results are passed in R7 R6 R7 H L or R4 R7 HH LL The assembler function may change all registers and may use bank 1 for temporaries if it is sure that the callers above have enabled bank 1 access which is the default If you pass more arguments to a function they will be stored in local memory for assembler usage this is not recommended it requires access to the call graph in this case it is better to pass a pointer to the assembler function How to use assembler There are two ways to write software in assembler The first put all assembler functions in one source file extension s51 a shown in some demos The second embed a block of assembler instructions in an asm endasm block of a C file This has the advantage that the C Preprocessor may be used too like in SRC RS232_2 RS232 C2 C If there is only one line of assembler you can use the Fasmline directive The instruction follow immediately asmline nop or in the next line asmline nop It is possible to include assembler in a C function but this is not recom
53. t assembler files to uC 51 is to use a text editor and some bulk search and replace 33 WWW WICKENHAEUSER COM uC 51 V1 10 User s Manual Appendix B A demo of uC 51 s optimisers In this appendix we made a comparison with the KXXX compiler V6 21 You can trace the results they offer a 2kB limited demo version The test function is some kind of bit banger shift something in and out This is the result of KXXX V6 21 it needs 35 bytes to solve the problem bit out bit bit in bit Simple 8 Bit Banger unsigned char test unsigned char ob int 17 unsigned char ib for i 0 1 lt 8 1i out_bit o0b amp 128 ib lt lt 1 if in bit ib 1 ob lt lt 1 return ib C51 COMPILER V6 21 BANG ASSEMBLY LISTING OF GENERATED OBJECT CODE FUNCTION bang BEGIN 22 Variable ib assigned to Register R6 22 Variable ob assigned to Register R7 Variable i assigned to Register R2 R3 0000 E4 CLR A 0001 FB OV R3 A 0002 FA OV R2 A 0003 2C0001 0003 EF OV A R7 0004 33 RLC A 0005 9200 R OV out_bit C 0007 EE OV A R6 0008 25E0 ADD A ACC 000A FE OV R6 A 000B 300003 R JNB in bit C0004 000E 430601 ORL AR6 01H 0011 200004 0011 EF OV A R7 0012 25E0 ADD A ACC 0014 FF OV R7 A 0015 OB INC R3 0016 BBOOOL CINE R3 00H C0009 0019 OA INC R2 001A 200009 001A EB MOV A R3 001B 6408 XRL A 08H 001D 4A ORL A R2 001E 70E3 JNZ 2C0001 0020 200002 0020 AF06 M
54. tant header files All functions work as the standard proposes The following two defines simplify the use of the 8051 s native data type and are quite common typedef unsigned int uint typedef unsigned char uchar void putc uchar reentrant reentrant because called indirect uchar getc void 30 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual uchar kbhit void printf and sprintf return the no of characters printed ANSI read more about the format string in an earlier chapter int printf far char pfmt print using putc int sprintf far char dest far char pfmt print to a string int puts far char ps result is always 1 ANSI The following two functions implement a pseudo random number generator based on a linear congruent algorithm The sequence will always be the same depending on seed A 4 Byte global variable will be used to keep the last result sourcecode in LIB LIB_C RAND C unsigned int rand void pseudo random between 0 65535 void srand unsigned int seed set starting value for the sequence Remark on a microcontroller a shifting register algorithm or one of the timer registers may be better suited we will show some alternatives in the next version Conversion functions for strings to integer or long values int atoi far char pc long int atol far char pc The following functions are non standard but often quite useful putsl is l
55. te library functions in C and then optimise the compiler to produce handcrafted quality Although it is more difficult at first it will pay of because the optimiser will surely reuse what he learnt by this More demos In SOURCES some more demos are found All of them can be compiled by loading their Make file in UmShell The folder SRC A51 does contain only one Make file for different projects select the target in the selection box of UmShell What s going on Now as you know how to write a C program it might be interesting to track it s way to a binary In the first step all C files are translated by the compiler UC51 EXE The compiler may require some system include files usually INCLUDE The compiler produces a plain assembler source file S51 Immediately after that the Assembler translates the compiler s output to an object file OBJ So the first step is the transition from C to OBJ For the next step the linker takes all object files at once and puts them together to a binary file BIN If there are still references left open the linker tries to get those missing refer ences from the supported libraries LIB you may pass as many libraries as you want to the WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual linker Together with the binary file a listing LST might be written and a memory map file MEM Both are intended to be read by debuggers or the user Basi
56. th FLASHMON or SLD51 Other 3 rd party downloaders might only support Hex files To instruct the UmShell to make a Hex file from the always generated binary file simply add a new line in the makefile Here the additional line would be hello hex hello bin More infos about makefiles is given in one of the following paragraphs More about C the ANSI compatibility of yC 51 To learn more about the C language we recommend to contact a bookstore or a public library Another endless source of information is the Internet Many primers and interesting articles may be found For the future a step by step manual ideal for educational purposes will be available We have designed the uC 51 for easy use and we have tried to get optimal compatibility with ANSI C Of course on a micro controller you won t find functions for disk access or similar But if you keep in mind that a 8051 has only very limited resources you could easily develop algorithms on your PC and then later transfer the software to the 8051 Large parts of the floating point libraries and other stuff of uC 51 have been designed with Borland C 5 the source code may be compiled with Borland C as well as with uC 51 Because of wC 51 s optimiser the generated code size is only slightly more than if coded by hand in Assembler Another example of portable code is the demo SRC DFHT DFHT C for which the PC s EXE is included We think it is the best solution to wri
57. ve other memory layout you can easily adapt the OS535 BIN by following the remarks in the source code and the appropriate make file OS535 BIN expects a LED on port P3 5 to let it blink if it is ready After a hardware reset the LED first flashes some times faster then keeps flashing slower If an error occurs data transmission the LED will flash irregularly In this case reset the hardware Of course the included demos for the two mixed signal micro controllers can only be used on their development boards or similar boards WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual Hello World Now start Edit our enclosed editor Enter the following include lt stdio h gt void main void printf Hello World n Save this text in SRC HELLO HELLO C might be already there Don t close Edit cm Mm S Now start UmShell This is the second part of the current IDE UmShell is based on an industrial approved system named Make For a beginner it might look a little bit strange but Make is a very powerful tool and in the background of most other IDE s a Make tool is working Think of Make as just a simple recipe how to build a target In this case the make file has only one line Hello bin hello c This tells Make that HELLO BIN is to be made from HELLO C By default UmShell knows a set of rules how to translate one extension to another i e C to BIN In
58. xadecimal digits 0 F For example the string R3 can be written as x5233 or x52 x33 Octals are a backslash followed by up to three octal digits 1000 For example R3 in octal could be written 11223 or 11221063 Mixing C and Assembler Mixing C and Assembler is very easy in uC 51 The compiler itself was designed for easy assembler usage Up to 8 bytes of arguments are passed in registers What s going on After reset the controller will jump to main trough a ljmp The first thing in main is to call startup This routine will initialize the global data of the program and initialize the stack pointer Then it will return to main After main is done startup will be called again 15 WWW WICKENHAEUSER COM wC 51 V1 10 User s Manual So if you want to call assembler functions from C you will find the controller s infra struc ture well prepared You even can even use this to get assembler data initialised by startup as we did in some demo and library functions Because the user might define variable of the same name as CPU registers like A and B we decided to user a leading in all compiler exported definitions A call from C to a function test will result as an Icall _test the compiler will write an assembler source code as outout The assembler can access all global C variables and vice versa but don t forget the consider the Parameter passing in registers is very ea
59. y determine the type of memory they are pointing to That is why they become generic pointers with a size of 32 Bit By calling the function say_hi uC 51 automatically extends a given pointer to a generic one if needed You might recognise that there is a 8 Bit overhead in the generic pointers Well you re right but we thought that this extra byte does not hurt more than it might be worth With such a 32 Bit generic pointer you can access 256 different types of memory each with a linear size of up to 16 MB We think this is almost flat too On some of our boards we already use this extra byte i e the FlexGate which has V1 0 512kB of Flash memory or the data loggers with 2MB The access over generic pointers is done through library functions You may find their source code in LIB LIB_ASS MEM32 S51 Feel free to add your own memory space After that you must rebuild the libraries as described later in this document For our data loggers we have mapped almost everything in this space the Flash with 2MB internal RAM even the PC peripherals have their own selector Summary All unmodified constant top level integral data and strings will be placed in code all other unmodified top level data will be paced in xram All unmodified pointers will become generic ones And what about this as a global definition char pc HELLO This is really difficult HELLO is a constant string OK So it will be lo
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