On 10/15/2016 08:38 PM, Segher Boessenkool wrote: > On Sat, Oct 15, 2016 at 06:49:45PM +0200, Gerrit Heitsch wrote: >>>> AFAIR the VIC-II row counter for refresh is free-running. I'll have >>>> a look later. >>> >>> It is reset at the end of the frame, actually. >> >> I wonder why they do that... Making sure that the counter can't get >> stuck somehow? > > Probably. The VIC-II does not have an external reset signal; instead, > most blocks rely on being reset some other way, usually from the frame > timing. The first frame output can be very, uhh, interesting. This > may be another reason why they opted for a separate (from matrix fetch) > refresh, btw. The same applies to TED by the way, no RESET input. It either comes up properly at power on or you're in trouble. > Another reason to reset the refresh counter every frame is to make sure > all frames are alike, which might help validation etc. As long as they meet the refresh specs it doesn't matter. Gerrit Message was sent through the cbm-hackers mailing listReceived on 2016-10-15 19:00:39
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