-----Original Message-----
From: Sami Khawam <a9501901@UNET.UNIVIE.AC.AT>
To: PICLIST@MITVMA.MIT.EDU <PICLIST@MITVMA.MIT.EDU>
Date: Thursday, October 30, 1997 19:19
Subject: Watchdog timer


>I have a simple question:
>How does the Watchdog know when the PIC
>is in an infinite loop? Is there a maximum lenght
>of this loop?


    It doesn't, the WDT is completly independant of most of the PIC, it has
it's own oscillator, runs despite of sleep mode, etc. It runs along, in the
background, and when it is finished counting it triggers an interrupt, if
enabled, that either resets the PIC, or wakes it up if the PIC was asleep.
The duration of a WDT timeout is dependant on many factors, voltage,
temperature, device characteristics, in fact microchip warns that under the
correct conditions, a WDT timeout could take up to a few seconds, something
to consider. TTYL