Re: VSP-Error once more

From: Gerrit Heitsch <*gerrit_at_laosinh.s.bawue.de*> Date: Wed, 2 Jun 2021 17:33:37 +0200 Message-ID: <46d4f9fb-ead6-a0af-5063-129bbc82d733_at_laosinh.s.bawue.de> · gerrit_at_laosinh.s.bawue.de

On 6/2/21 5:03 PM, groepaz_at_gmx.net wrote:
> Am Mittwoch, 2. Juni 2021, 14:58:04 CEST schrieb silverdr_at_wfmh.org.pl:
>> Do we know / have any data about what board/VIV-II combination is the most
>> prone to the said error? So far I was able to reliably reproduce it (with
>> VSP-Lab) using 250425 board and 6567R56A VIC-II (which is in fact quite
>> different from all other variants in respect to timings) but I need to test
>> it on PAL too. While I remember finding hardware combination exposing the
>> issue some good time ago but now I seem to be unable to find it again.
> 
> It depends very much on the individual components on the board (PLA. RAMs,
> VICII, probably more).

The PLA should not be involved since /RAS doesn't go through the PLA. 
 From how I understand how it works (address lines changing too close to 
/RAS going LOW), it would be a combination of VIC and RAMs and maybe 
clock jitter. Plus, of course, temperature.

  Gerrit