On Wed, 6 Aug 2003, Mike Singer wrote:

> andre abelian wrote:
> > I guess mastering (interrupt service routine) is not easy.
> > Even I get precise timing after adding more codes timing
> > gets changed; more adjustments needed more changes needed.
> >
> > I also found one more problem with mplab 6.22. Using same
> > code with mplab 6.22 will generate different timing on
> > timer0 then mplab 6.30 does.
>
> Is this interrupt's hassle really needed?
>
> Google with:
> "Timer polling Scott Dattalo"
> or "isochronous code Scott Dattalo"

Interesting, the first link has code attributed to me that I know I didn't
write (I never have written anything for an SX)

I wanted to suggest the isochronous approach earlier, but I'm not sure I
understand what Andre really wants. If he's beating his head against a
simple interrupt issue, then I'm not sure how or if isochronous coding
will make his life easier. BTW, if this is for a midrange part, isn't true
that most of the time the interrupt latency is 1 instruction cycle, but
sometimes it's 2? In which case, any software based delay based on
interrupts will have 1 cycle of jitter.

Scott

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