AW: [avr-gcc-list] Timer Interrupt Problem on ATmega 103L

[Peter Hierholzer]

Hi Andrew,

> -----Ursprüngliche Nachricht-----
> Von: 'Andrew McNabb' [mailto:address@hidden
> Gesendet: Donnerstag, 27. Mai 2004 23:55
> An: Rune Christensen
> Cc: Peter Hierholzer; address@hidden
> Betreff: Re: [avr-gcc-list] Timer Interrupt Problem on ATmega 103L
> 
> I've been playing around with everything I can think of or have been
> recommended on the list.  I've finally noticed that under certain
> circumstances I can get _something_ to happen when I enable interrupts.
> I just don't know what it means.  Let me try to explain:
> 
> When my main loop just outputs TCNT0, it doesn't make any difference
> whether interrupts are on or off.  Either way the lights are counting
> from 0 to 0xff over and over.
> 
> However when I add something to my while loop that polls TCNT0 to check
> "manually" whether there's been an overflow, the behavior depends on
> whether or not I've set TOIE0 in TIMSK.  If TOIE0 is not set, everything
> works properly and the lights flip on and off every second.  However if
> TOIE0 is set, the lights on PORTB all turn on and stay on.  But if the
> while loop is empty, the lights stay off.
> 
> I can't quite put a finger on what's going on.  Does anyone have any
> ideas?
> 
> Here's my code in its current form.  Thanks.
> 

Can you post a mixed source assembler listing of the code

Peter