Hello all,

The problem I am currently working on involves a Watch Dog Timer on a Winbond W77C32 processor (like a Dallas 8xC320). Winbond has checked my WDT code, which initializes the WDT and periodically resets it. They said it was OK, for what that's worth. My problem is that when the WDT expires, the actual system reset doesn't happen (or at least my system doesn't go back and start from the beginning like I expect).

Initially I had the WDT interrupts enabled, and used that to determine where the resets should be to keep it from timing out. Once I was sure I had them in the right places, I disabled the interrupt and enabled system reset by the WDT. The code ran just fine, like I expected/hoped.

But when I purposely broke the code (inserted a do-nothing forever loop) to see how the reset worked, nothing happened (that I could see). It just hung like it would have if a WDT wasn't present.

So I was trying another approach, where I re-enabled the WDT interrupt, and in the WDT ISR checked to see if EWT (watch dog timer reset enable) was set; if so then call a software reset. But this too isn't working. Sort of the opposite to the recommended practice of using the WDT to reset the system, I know, I know. But like I said, it didn't work anyway.

I'm wondering if it's trying to reset, or is actually resetting, but for some reason isn't running. At this point my visibility into the processor is pretty much zero, and I'm running out of ideas on what might be causing it, and what else I might look at to see what's happening or just gather more clues.

Any suggestions or ideas? Thanks for any help!

Dennis