SDCC compiler & accurate delay function

Hello all

I have just started using the SDCC compiler for 8051.
I am trying to write an assembler function (Delay) inside a C file. It has to be written in assembler because the delay has to be accurate. I then want to call this function from a C function:


_asm
Delay:
mov r0, #FF
d100: djnz r0, d100
ret
_endasm


main()
{
_asm
call Delay
-endasm
}

The above code does not compile.
Is this possible to do some how?
Is there a better way to create an accurate delay function?

Thanks

i guess it should be the other way

delay(){
_asm
mov r0, #FF
d100: djnz r0, d100
_endasm
}

and in main.. call delay as a function

Thanks, this is correct, but then I am not sure I know how to calcuate the time (clocks) required for calling the delay function in C. This may cause a samll error in the delay time. Am I correct?

not much.. after compiling its just a call to the function nothing much.
calling a function takes about 3 machine cycles, ret need 2 and rest is whats inside your loop
i have explained someone regarding how to calculate delay.. you can check that thread..

OK, thanks a lot!