625M clock noise maybe from 125M clocksource， or 25M This might be from ethernet Do you use GIGA ethernet ? And Try to unplug the RJ45 cable
2014-05-15 5:01 GMT+08:00 Gerald Coley <ger...@beagleboard.org>: > OK. Understood. Different test equipment will yield different results. And > it can be effected by the SW you are running. > > Gerald > > > On Wed, May 14, 2014 at 3:59 PM, <l...@ansync.com> wrote: > >> It's not something unique to our board--a stock BBB has the same problem. >> >> >> On Wednesday, May 14, 2014 1:41:29 PM UTC-7, Gerald wrote: >> >>> Sounds like you may have grounding issues or unterminated pin . Using a >>> probe should let you be able to determine which side of the chip it is. >>> >>> Gerald >>> >>> >>> >>> On Wed, May 14, 2014 at 3:37 PM, <l...@ansync.com> wrote: >>> >>>> It seems to come from right around the processor, but we couldn't >>>> pinpoint it any more precisely than that, or even to one side of the board >>>> or other. >>>> >>>> >>>> On Wednesday, May 14, 2014 10:56:28 AM UTC-7, Gerald wrote: >>>> >>>>> In order to mitigate it you need to figure out where it >>>>> is coming from. A probe test will help in that area. Have you run one? >>>>> Using ferrites on all cables generally helps in these types of issues. >>>>> >>>>> Gerald >>>>> >>>>> >>>>> >>>>> On Wed, May 14, 2014 at 12:01 PM, <l...@ansync.com> wrote: >>>>> >>>>>> We have a BBB-based design currently undergoing FCC testing, and >>>>>> they've found a bit of noise at 625 MHz. Has anyone else encountered >>>>>> this, >>>>>> or know what it might be, or how to mitigate it? >>>>>> >>>>>> -- >>>>>> 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 beagleboard...@googlegroups.com. >>>>>> >>>>>> For more options, visit https://groups.google.com/d/optout. >>>>>> >>>>> >>>>> -- >>>> 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 beagleboard...@googlegroups.com. >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> >>> -- >> 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 beagleboard+unsubscr...@googlegroups.com. >> For more options, visit https://groups.google.com/d/optout. >> > > -- > 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 beagleboard+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- 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 beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
