Lpc2000

--- In lpc2000@yahoogroups.com, "Andrew Berney" <amb@...> wrote:
> Personally I simply use one of the on chip
> timers to give me an interrupt every so often and then kick the 
watchdog
> inside it's IRQ handler...
> 
> Andy

Andy,

Can you explain more about how you're using the watchdog, as what you 
say sounds a bit strange if you take it at face value?

One of the functions of a watchdog is to reset a system to a known 
state to recover from (previously unknown) software (or indeed 
hardware induced) errors. If the software error involves entering an 
infinite loop then a timer interrupt that just feeds the watchdog 
won't recover the system: the watchdog will never expire.

No doubt you're doing something else: for example in the timer 
interrupt you could check one or more status fields that are 
continuously updated by parts of the application and only feed the 
watchdog if everything is looking good.

Also, you still need to ensure interrupts are disabled for the feed 
sequence, unless you don't allow nested interrupts.

Just in case anyone reading your post gets the wrong idea it might be 
worth clarifying these points.

Brendan.