Lpc2000

See "USAGE NOTES ON WATCHDOG RESET AND EXTERNAL START" on page 214 of 
the 2124 User Manual (Dated May 03, 2004).  Does this solve your 
problem.

Assuming state of these pins is OK, I had the followin thoughts:

You say that you have to cycle the power to recover.

Did you try activating the Reset pin without removing power?

If your theory about the watchdog reset is correct, then activating 
the Reset pin should recover.  If activating the Reset pin does not 
recover, then the problem is not the watchdog reset.  Rather, the 
chip is getting into some sort of hardware latch-up which requires 
power cycling to recover - if that is true, adding an external 
watchdog (to trigger a reset) will not help you, unless you have the 
external watchdog toggle the power.



--- In lpc2000@yahoogroups.com, "mjbcswitzerland" 
<mjbcswitzerland@y...> wrote:
> 
> However.... What I do is put a mobile phone right next to the board 
> and make a call. The board often dies and it is necessary to remove 
> power and reapply it to get it to work again (after removing the 
> source of interference). This means that the internal watchdog is 
> not really doing its job because I would hope the board to at least 
> continue with a reset so that it is not dead until some special 
> intervention.
> 
> So what is happening? I wonder whether the following may be true:
> - The internal watchdog is not active after a reset and it is up to 
> the software to start it - which it does. 
> - Heavy interference causes the board to fail and the watchdog 
> fires, causing the processor to reset.
> - The heavy interference is still present and so the processor is 
> not running correctly.
> - The heavy interference is removed.
> - The processor is in an undefined state and so the software is not 
> operating correctly and thus didn't restart the watchdog.
> - No help comes from the (not activated) watchdog.
> - This state remains indefinately (or until someone is called out 
> and power cycles the equipment).
>