發信人: reflection (似水流年), 信區: EEtechnology 

標  題: C51 Primer (13) Outputs from C51 

發信站: 南京大學小百合站 (Wed Nov 24 12:05:12 1999), 轉信 

  

  

13 Outputs From C51 

13.1 Object Files 

Being closely related to the original Intel tools, C51 defaults to the Intel 

 object file format. This is a binary file containing the symbolic informati 

on necessary for debugging with in-circuit emulators etc.. It may be linked 

with object files from either Intel PLM51 or ASM51 using the Keil L51 linker 

. The final output is Intel OMF51. 

Versions >2.3 of the compiler will produce an extended Intel OMF51 object fi 

le if the DEBUG OBJECTEXTEND command line switches are used. This passes typ 

e and scope information into the OMF51 file which any debugger/in-circuit em 

ulator should be able to use. The extensions to the original Intel format ar 

e a proprietary Keil development but have been widely copied by IAR et al. 

13.2 HEX Files For EPROM Blowing 

To blow EPROMS an additional stage is usually necessary to get a HEX file. T 

his is an ASCII representation of the final program without any symbol infor 

mation. Almost every EPROM programmer will understand Intel HEX. The OH51/OH 

S51 utility performs the conversion from the linker's OMF51 file to the stan 



dard 8bit Intel HEX format. 

13.3 Assembler Output 

Optionally, a valid A51 assembler/C source listing file can be produced by C 

51 if the SRC command line switch is used. This has the original C source li 

nes interleaved with the assembler and is very useful for getting to know ho 

w the compiler drives the 8051. 

Do not be tempted to try hand-tweaking the compiler's efforts. Whilst you ma 

y be able to save the odd instruction here and there, you will create a tota 

lly unmaintainable program! It is much better to structure source code so th 

at you write efficient code from the start. Simple, efficient C will produce 

 the best 8051 code. 

---------------------------------------------------------------------------- 

---- 

  

-- 

Ours is essentially a tragic age, so we refuse to take it tragically.