AVR-Chat

>
> I know this sounds a simple "of course" type question but:
>
> I could have the controller output a 10uSec pulse and read it with a
> logic analyzer to verify that the timing is correct.

  If I were concerned I would make sure that the chip is "rail-to-rail"
powering the oscillator and simply put a scope on the oscillator output.

DLC

> [This verifies that the caps are correct for the oscillator]

> Correct assumption?
>
>
>
> --- In AVR-Chat@yahoogroups.com, David VanHorn <microbrix@...> wrote:
>>
>> On Mon, Feb 23, 2009 at 12:54 PM, David Appleton <englsprogeny@...>
> 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.
>>
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-- 
Dennis Clark
TTT Enterprises