to combine C language program and ASSEMBLY language program

The only place to find the answer to this is the documentation of your C compiler, since this is implementation dependent.

Meindert

The chances of me guessing which compiler you are using a pretty slim. Have you read the compiler documentation?

Regards, Richard.

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An educated guess is - Your probably using the Keil Complier.

Yes, you can pass arguments in a C function to ASM.

Answer here

All about the Keil C51 complier here.

You need to read up in your compiler manual on things like (at a bare minimum) how it passes arguments, which registers you're allowed to trash and which ones you need to preserve, and how it expects results to be returned.

As to inline assembly (if that's what your question refers to), you need to read up on that too in your compiler manual.

Hi, thanks for reply. i m using Keil Compiler. can u suggest me the way if possible, to write a 7 line assembly code in the middle of C language program. also i want to use one parameter from C language program.

Hi, thanks for reply. Yes, i m using Keil Compiler. can u suggest me the way if possible, to write a 7 line assembly code in the middle of C language program. also i want to use one parameter from C language program.

The easiest way I know is to write the asm program in a separate file and just add this to your project. This way, you're not writing inline asm code but rather a c-callable function in assembler. A single parameter is passed from C to your function in r6:r7 (int) or r7 (char). You have to start your function's name with an underscore in the asm file:

.public _myfunc

_myfunc: inc r7 ret

In the c file, you declare your function as extern e.g.

extern char myfunc (char);

please tell me how do i take a return value( if it is a char) from assembly program. i call a assembly function like this unsigned char sum = funtion( j ) ; in what register i have to store my value which i want to return.

Again, that is in the documentation of your compiler!!!

Meindert

r7

Assuming you're using C51