AVR-Chat

On Mon, Feb 23, 2009 at 12:54 PM, David Appleton <englsprogeny@yahoo.com> wrote:
>
>
> Could we also do a timer test?
> Is 10uSec really 10uSec?

The problem is that you have nothing to reference it to, other than
the crystal, unless you have some independent external timebase.

A 60Hz line signal would do, 32kHz crystal...

The WDT is good for detecting the system running slower than it
should, but not for faster!

With an external timebase, you can put a window around it, and if the
pulse isn't present, or the period seems abnormal, then go into an
appropriate "fail safe" mode.