AVR-Chat

On Jun 5, 2005, at 10:50 AM, Kathy Quinlan wrote:

> Hi all,
>
> I have a problem with a project. I can see the problem externally, I
> have a counter that counts from 1 to 255, ticks over to 0 and  
> counts up
> again....
>
> Sometimes during the operation, the counter resets to 1 and starts  
> again.

That sounds a lot like an interrupt vector is undefined by your  
application and is executing the default vector which is usually the  
startup/initialization code.

Its the kind of thing that could be hard to track down. I don't know  
of a way for a routine to extract the vector which called it. Write  
such a routine and substitute for the default. Otherwise one is stuck  
writing a unique IRQ service routine for each and every IRQ vector.  
Do something unique in each routine and you'll know which is getting  
dispatched.

--
David Kelly N4HHE, dkelly@HiWAAY.net
========================================================================
Whom computers would destroy, they must first drive mad.