RE: [avr-chat] Interrupts from assync timer in sleepmode

[Larry Barello]

Isn't the issue that you need to wait up to one asynchronous cycle after
waking up before going back to sleep?  The data sheets indicate that it
takes one cycle of the asynchronous clock (~30us) to reset the interrupt
logic.  If that doesn't happen the next compare won't register.  30us is a
relatively long time on a mega128... potentially 480 instructions.

I have never used this feature before, so that is just my interpretation of
the datasheet.  However, I do recall this sort of discussion in the recent
past... 

-----------
Larry Barello
www.barello.net


| -----Original Message-----
| From: address@hidden [mailto:avr-chat-
| address@hidden On Behalf Of Nils Springob
| Sent: Thursday, September 22, 2005 6:36 AM
| To: Bjarne Laursen
| Cc: address@hidden
| Subject: Re: [avr-chat] Interrupts from assync timer in sleepmode
| 
| > AS0 is 1, that is what make it an ansyncrone timer. The timer runs from
| > the 32768 Hz crystal as it should.
| 
| do you write to the OCR0 or TCNT0 just before entering sleep mode?
| 
| 
| _______________________________________________
| AVR-chat mailing list
| address@hidden
| http://lists.nongnu.org/mailman/listinfo/avr-chat