Get one of the latest version and try it. There was a change made back on Rev A6 that tied the 3V3B power up to the 3V3A. The 3V3B rail was coming up before the 3V3A rail. That may help this issue.
Gerald On Fri, Dec 20, 2013 at 10:32 AM, Gerald Coley <[email protected]>wrote: > Could be. That issue we have not seen. The one we did see was addressed by > the capacitor change. I will look at this for a later revision, assuming we > can duplicate it. But it won't be in the next revision for sure. > > Gerald > > > > On Fri, Dec 20, 2013 at 10:26 AM, <[email protected]> wrote: > >> Thanks Gerald. >> >> You changed C24 to a 2.2uF capacitor to improve the reset signal but we >> don't think that fix the issue. >> We made some measurements around UART0 and we are convinced that u-boot >> detects spurious data during start up. Find below 2 ocilloscope screenshots >> (CH1 : PIN 3-J1 B_UART0_TX, CH2 : PIN 4-J1 B_UART0_RX). >> http://hpics.li/9d7742f >> http://hpics.li/956957a >> RX signal looks noisy when TX signal changes. Maybe a coupling issue? >> >> Regards, >> >> Ludovic >> >> -- >> 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]. >> For more options, visit https://groups.google.com/groups/opt_out. >> > > -- 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]. For more options, visit https://groups.google.com/groups/opt_out.
