How to mix C & assembly

Hello friends,


presently i am working on microcontrollers and I am using Keil compiler to progrm.
I want to know how to mix embedded c and assembly in a single program
plz help me.

Thank you.
john

hi
when u r writing a c function that hasto be used in assembly again declare that c function as global in c program and in asm declare it as extern and call it similiarly u can do for asm program also (declaring fun as global abd acessing it as extern).

When you want to use assembly in a C program, you have to use a pragma directive.


It is called inline assembly, if you want to search for it in the user manuals.

Hope it helps,

cyberblak

hi cyberblak


can i know more about pragma?where can i find more information about it?which user manual are you talking about?if you have that manual,could you share for me here?any links or websites you now,related to this?how do i know when to mix assembly in C program or not?when should i go for this mixing?what will be the effect on the code?can you clarify me?

regards
john

I am not an expert, but mixing C and ASM code is described in C51.PDF, Chapter 6 Segment Naming Conventions (p.159) and next, especially Interfacing C Programs to Assembler (p.163). This file is inside keil_home\C51\HLP directory.
Hope it helps.

hi jan noha


thanks for your siggestion,i shall check out the C51.PDF,chapter 6.

regards
john

Salam,

Read Chapter 5 ( page 88 )

"Final Word on 8051"

**broken link removed**

Thanks

hi sphinx

thanks for the link,i think its good tutorial.i found a good book which has information about C and assembly.its Fundamentals of Embedded Sodftware by Lewis,u can download the book from internet,by search through google,its easily available.the book tells about Where C and Asssembly meets,also this book is very good for RTOS concepts.

regards
john

Added after 1 hours 58 minutes:

MODERATOR ACTION: interesting to see you answering your own questions??
hi all,


Usually, embedded C compilers include a keyword such as "asm". The
syntax varies between compilers (because it's not a standard).
Sometimes it's spelt "assem" or "#pragma assembler" or something like
that. However, "asm" is most typical. The statements will be
something along the line of:

asm "nop";

or

asm { nop; mov a,b; }

or something vaguely like that.

Hope this helps.



regards
john