Lpc2000

One thing which will kill your internal Watchdog is writing a large 
value to the WDTC register.  While the WDMOD register is write-
protected, this register is not.

Also, even though WDMOD is protected from writes by the core, could 
static possibly change the setting of one of its bits?

Also, is it possible that static could cause a Reset, and then crash 
the processor before the code has a chance to set the WDEN bit?



--- In lpc2000@yahoogroups.com, "lhaddix" <lhaddix@i...> wrote:
>
> I guess as Marcio points out the larger issue is why are there
> situations where the internal watchdog can't reset the micro.
> Unfortunately this is probably a feature of the LPC design.
> 
> Microchip uses an internal RC for thier watchdog which is not
> dependant of the system clock for instance.
> 
> I think what happens is it's possible for an ESD hit to stop
> the crystal osc on the LPC such that reset is needed to restart
> the oscillator, but there can be no watchdog reset without a system 
> clock.
> 
> I've considered using an external osc to feed the ARM, but don't
> wish to do this. I can't be sure it would fix the problem without
> mocking it up and then blasting with the static gun, but I know that
> toggling reset from outside will restart the clock. 
> 
> Landrum
>