Lpc2000

--- In lpc2000@yahoogroups.com, Robert Adsett <subscriptions@...> wrote:

> I prefer that the device get back to a known good state as soon as 
> possible.  Keeping the output in the (possibly bad) state it was in is 
> definitely the last thing I want in that eventuality.  That can be
done in 
> SW but it does increase the latency.

If your software is in deadlock, and output is in bad state, and you
want to set it back, it would take you no more than a few microseconds.

What is your watchdog timeout?  Milliseconds?  Seconds?  What is a few
microsecond latency in comparision?

Would you still say latency is an issue?

As for other processers doing this, sure it is okay to do this if
there are no ill side effects.  In the case of LPC we know there are
ill side effects.

I had to use watchdog on COP8 processor once in telephone hardare to
meet failsafe requrements.  It was not acceptable if the current call
in progress was interrupted by a failsafe recovery triggered by the
watchdog timer.

Any procesor that does a full reset will not meet such requirements.

Jaya