AVR-Chat

The external WDT can easily be used to set off an external alarm if the 
controller gets too pooped to participate.  It can also be used to turn 
on another controller whose job it would be to set off an alarm and shut 
down the system in a reasonable manner to a safe state.




David Kelly wrote:
> On Jun 17, 2008, at 5:45 PM, Philippe Habib wrote:
>
>   
>> In my case, it is required.  The fear is that if the micro dies in
>> such a way that the watchdog doesn't work either you'd be in trouble,
>> so you have an external watchdog which does the reset.  You also have
>> some other way of detecting a dead micro and then arrange to fail in
>> a "good" way.
>>     
>
>
> So its based on fear rather than fact?
>
> Fear that the watchdog is implemented as a software function that will  
> fail the same way when/if the CPU fails? But if that was the case  
> wouldn't the CPU be smoked and beyond recovery via reset?
>
> --
> David Kelly N4HHE, dkelly@HiWAAY.net
> ========================================================================
> Whom computers would destroy, they must first drive mad.
>   
>


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