Re: [avr-gcc-list] T/C1 CTC mode strange behavior...

[George Kalovyrnas]

When the interrupt occurs, the timer rolls over and counts starting from 0
again.
The problem is that you use the Clear On Compare Match (CTC1 flag). If you
clear this flag (on setup)
the counter would continue to count beyond 384.

>
> Hello everybody...
>
> I use the big guy (a.k.a. AT90S8535) mC. I'm setting up an ISR for the
> clear on compare match interrupt of the Timer1. I also set the OCR1A
register's
> value to 384 and I launch the timer with initial value zero, and no
prescaling.
> So far, so good...
>
> When I check the value of the TCNT1 inside from the ISR, it seems that it
> equals to 356 (which is of course < 384). What's going on here???
>
> Regards,
>
> --
> John Yannakopoulos.
>
> PS: My setting is as follows: AVR AT90S8535 mC, avr-gcc in a linux
environment,
>     avr-libc, and in-system programming using uisp.
>
>