On 08/28/2012 01:39 PM, Anisha Gorur wrote: > Thats actually what we are using, however, when printing out the tick > count, we randomly, and only sometimes, see a jump of about 30 ticks, and > if each tick is 10ns, that is a huge 300ns jump. Do you know why this could > be happening? >
I'm very lost. Where are you getting the time_spec from? A receive packet? usrp.get_time_now()? Or is this a time difference between devices? get_time_now is completely asynchronous to the device, if thats what you are calling in a loop, I would expect to see a lot of variation in time deltas. -josh > We are using gpsdo's as both a time and clock reference, though this > problem seems to occur even if we set the clock and time reference to > external. However, setting them to gpsdo seems to make it more stable, as > we have seen the ~30 tick jump fewer times with those references. Another > question is why would there be a big difference in what the reference is > set as when either way, supposedly the internal GPSDO is being used. > > Thanks, > > On Tue, Aug 28, 2012 at 4:13 PM, Josh Blum <j...@ettus.com> wrote: > >> >> >> On 08/28/2012 12:03 PM, Anisha Gorur wrote: >>> Hello, >>> We've been having some trouble with the synchronizing aspects of our >>> project. What we want is the exact same time as the FPGA tick counter, >> not >>> a time_spec_t representation of time. Where can we get access to that? >>> Thanks! >>> -Anisha >>> >>> >> >> call to_ticks with the clock rate of the device: >> >> http://files.ettus.com/uhd_docs/doxygen/html/classuhd_1_1time__spec__t.html#ad75960ba4c788cd30a5d0c8904888da3 >> >> -josh >> >>> >>> _______________________________________________ >>> Discuss-gnuradio mailing list >>> Discuss-gnuradio@gnu.org >>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >>> >> >> _______________________________________________ >> Discuss-gnuradio mailing list >> Discuss-gnuradio@gnu.org >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> > > > _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio