Ok, so I have the clock coming in @ 4MHz, effectively 1MHz to the processor.
If I set the prescalar to 1 and assign it to the WDT I'll get a 1:1
prescalar and an interrupt every ~244us.  Now I know that I can add to that
value to speed it up so that's good, but my one problem with this is, I
don't want to use the Watchdog timer... If I have it disabled but still
assign the prescalar to the watchdog, will it be disabled?  The /only/
interrupt I want is the tmr0 one.

> >Just double checking this.  At 4MHz, the timer will interrupt every:
> >256((2^(prescaler+1)/(2^22)) seconds.  So with a 0 prescalar you'll be
> >getting an interrupt every: 256(2/(2^22)) seconds (122us)?  This
> appears to
> >be the smallest obtainable period with this clock speed.  If anyone can
> >confirm this, it'd be much appreciated!!
>
> No, actually at 4MHz, TMR0 will interrupt every 256us with a 1:1
> prescaler.
>
> >sheet, I'd appreciate that too.  The datasheet merely says 1:2 .. 1:256
> >prescalars are available and I only assume that means
> clock/2^(prescale+1).
>
> The datasheet says that the minimum prescale value for TMR0 is 1:2 when
> assigned to TMR0.  To achieve a 1:1 scale for TMR0, assign the
> prescaler to
> the WDT instead of TMR0.
>
> --Andrew

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