Olin Lathrop wrote:
>
> > What's the best strategy for dealing with updating
> > a 10-bit PWM value asynchronously with TMR2?
> >
> > It looks like you could get a glitch if the update
> > happens to occur just as TMR2 is overflowing.
>
> I've thought about this too.  In the end I just updated the high 8 bits,
> then the low two bits as quickly as possible thereafter.  Since PWM is
> usually used to achieve an average duty cycle over a longer time interval
> than the PWM frequency, I think you can just ignore the glitch because the
> average will still be correct.  Yeah, I know, I'd feel better too if all 10
> bits were properly double buffered in the hardware.


I poll timer2 and only change the registers in a
time when the change will not affect the PWM
output. Most of my apps use some type of polling
to get the best hardware performance, and I also
like to synchronise timer1 or timer2 a few insts
after timer0 which I use for the main int, as I can
then handle timer1/timer2 overflow issues at the
end of the timer0 int, before any code processing
gets to take place. Hope that makes sense. :o)
-Roman

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