On Feb 26, 2014, at 8:13 AM, Gerrit Heitsch <gerrit@laosinh.s.bawue.de> wrote: > On 02/25/2014 09:44 PM, silverdr@wfmh.org.pl wrote: >> On 2014-02-25 at 20:49:07, Gerrit Heitsch (gerrit@laosinh.s.bawue.de) wrote: >> >>> The fun part is, if you look at a chip itself and measure just between >>> +5V and GND of that chip, everything is a bit noisy, but not really >>> bad. >>> >>> It's just that the ends of the board in relation to each other do >>> funny >>> things. The 1V peak-to-peak is only a few ns, and a half cycle is >>> about 500ns. >> >> Well, this doesn’t mean such thing can be “written off” due to the length of the pulses. Of course it depends on various things but it still can be a disruptive factor for regular operations even if those are short. > > Also, remember, the image I mailed you shows the difference in GND potential between the 2 points far away from each other. When you take a closer look at Vcc and GND on each IC, it's still noisy, but a lot less so. Sounds like ground bounce, possibly solvable by finding the responsible line drivers and providing decoupling caps. -Nate Message was sent through the cbm-hackers mailing listReceived on 2014-02-27 08:00:13
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