Hi vincent,

how about writing a  wdt service routine that checks to see what
caused the reset condition, then branches to appropriate routines
based on cause? it would have to id sleep, powerup, mclr, and
wdtimeout.  then you still retain the ability to reset device but can
capture wdtimeouts and route them instead of resetting.  ive never
done this for a 16c74, but there should be a way by reading the
status register to determine the source of the timeout.  i know that
sleep on a 16c74 returns to origin, so the routine must be located
there.  think of it as a sort of interrupt service.....

alice


> I am currently using a 16C74 in a low-power app.  To avoid excessive power
> drain, I would like to use the WDT as a timer to wake up the PIC, run a
> short routine, then return to sleep mode.  My problem is, the application
> will require some routines to run longer than the WDT would otherwise
> allow, and it is not acceptable to be continuously clearing the WDT timer
> registers (because failing to clear them in time and causing a reset would
> be catestrophic).
>
> Can anyone suggest a way to take advantage of the power-saving
> capabilities (killing the OSC) without having to worry about generating a
> false WDT reset?  Any suggestions regarding this, or any other
> power-saving functionality would be greatly appreciated.
>
> Regards,
>
> Vince Deno
>