After playing around a bit more with this I found it is a problem of BeagleBone Green. With a BeagleBone Black my hardware shows this PHY-problem for about once every 50 boot-ups, with the BBG it happens once on four power-ups.
So: has anybody an idea what is different between both that could have an influence on this? Am Dienstag, 21. Juni 2016 07:17:32 UTC+2 schrieb Karl Karpfen: > > I played around a bit with this and it is quite strange: > > When I reset the board by pressing the reset-button on BBG, on next > boot-up the Ethernet PHY is working smoothly. > > When I do the same programmatically by invoking a cold reset on SoC (by > writing a 0x02 into reset register 0x44E00F00, the PHY stays in same > unusable condition. According to TRM of AM335x such a reset should pull > output NRESETIN_OUT to LOW which should be the same like pressing the > reset-button. > > Any idea why one is working and the other not although they should be the > same? > > > > Am Samstag, 18. Juni 2016 16:44:20 UTC+2 schrieb Karl Karpfen: >> >> Hi, >> >> I know there is a problem where the Ethernet (PHY?) in some seldom cases >> isn't initialised properly on power-up ending up in a state where it can't >> be used and therefore Ethernet is disabled. Now I have a BBG-cape where >> this happens much more often than I know this from a plain BBB. Two >> questions on this: >> >> 1. The BBG is powered externally by feeding 5V into VDD. Could a >> not-so-steep power-on rising edge of VDD make this problem happen more >> often? >> >> 2. When I'm in this state and press the reset-button on BBG, the problem >> is solved when the board is back. Is there a possibility to invoke >> something similar out of software by accessing the PMIC somehow? If yes - >> what would have to be done? >> >> Thanks and keep the good work going! :-) >> >> Karl >> >> -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/5210a94b-6cf8-4e53-8eef-dc27cdd6c682%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
