Workshop Users wrote:
>
> Hi to all. I am new to using PIC's and am a but stuck.
> I want to count down from 8999 (d) to zero in 60ms , and then repeat.
> This works out as counting at about 150khz. Am using a pic 16c84 at 4Mhz.
> I wrote a routine to do this , but as I am  a beginner my code was not all
> that good:0) ,
> and it took to many instruction cycles and was hence to slow.It needs to
> count at
> 1 count per 6.6us about.I can use TMR0 and I can use an external clock
> source
> if need be.
> Am I going to have problems because the PIC is to slow maybe?
> Any help would be appreciated.
> Cheers all
> Rob

; PULSOUT port, pin, time
; Generates an output pulse in 10-cycle (10 us at 4 MHz) units,
; based on a 16-bit (1 to 65,535) value. The pulse is the reverse
; of the pin's state when pulsout is called. For instance,  if the
; specified pin is initially 1, Pulsout will invert it to make a
; negative-going pulse.

Half of Pulsout's 10-cycle delay is produced with nop instructions. If
you want a 5-cycle version of Pulsout, remove the nops.

found at:
http://www.dontronics.com/convert2.html#pulsout

Don McKenzie  mailto:don@dontronics.com http://www.dontronics.com

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