AVR-Chat

>> The WDT is good for detecting the system running slower than it
>> should, but not for faster!
>
> You mean like this?
>
> http://focus.ti.com/lit/ds/symlink/tps3813k33.pdf

Only if you never want to put the AVR to sleep to save
batteries.

68HC11 handled this case far better than other parts
I've used.  It has a specific "Clock Operating Properly; COP"
section.  The COP has its own clock source.  If the COP
detects the main Osc. has failed it generates a clock and
an interrupt.  You are then in a "limp a long" mode so you can
do a clean shutdown.




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