Wan Zulhelmi Wan Ahmad Kamar wrote:
> Anybody has any idea how to implement delay for PIC18f.  My friend
> taught me a way to do it which is with NOP for delay but then that
> would be redundant.  It was something about 4MHz/4 = 1 MHz per
> instruction == 1us.  It's through counting instruction cycle.

For short delays of a few instructions, I use the WAITNOP macro in
STD.INS.ASPIC at http://www.embedinc.com/pic.  You pass it the number of
cycles to waste, and it uses GOTO or BRA instructions as 2 cycles NOPs when
possible.  Or course you have to make sure interrupts are off unless it's OK
for the delay to take a lot longer sometimes.

For long delays, don't use delays at all.  Set up a periodic timer interrupt
and trigger functions on this timer clock tick, or multiples of the clock
tick.


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