For reliable software delays you really should code the delay subroutine(s) in assembly language like suggested by others. If you configure a subroutine for say a 1Msec delay then you can make it in normal assembler and write the prototype for it in C simply as:

void Delay1MSec(void);

...This can be called from C easily as:

Delay1MSec();

..Easy as pie.

For assistance on designing the delay subroutine to get it just right please see my delay subroutine calculator. It is an EXCEL spreadsheet download so you must have EXCEL for it to work.

Michael Karas