HI Anusha, this is the wrong mailing list for this -- for your replies, I think it's best to join usrp-us...@lists.ettus.com [1] and continue this discussion there; I will crosspost my answer.
On 23.07.2014 18:56, Yarlagadda, Anusha (337G) wrote: > Hi, > I am using URSPN210 series, have few questions regarding the clocking > schemes for this USRP N210. In the website, its mentioned USRP2 and N200/N210 > have fixed 100MHz clock which can't be tuned and do not have option to use > external clock. You *can* use an external clock, but it should be a 10MHz one. > > We would like to use a different clock rate (49.2MHz) instead of the fixed > 100MHz that is generated from the Reference and system clock generation > circuit( I think all these clocks i.e fpga clock, TX/RX clock for the RF > boaord ADC/DAC clock are generated by the AD9510 that has on chip PLL core > and multi ouput clock distribution function). I'm afraid that doesn't fit the N210 design. You can't use an arbitrary clock rate -- the idea is to decimate your signal to a integer fraction of the master clock rate, and transport the signal at that sampling rate to the host pc for further processing, e.g. resampling. Furthermore, I'm a little curious what kind of system would preferably have a sampling rate of $49.2MHz/n, n \in [2,3,4,...]$ -- please be aware that you can't fit 49.2 MS/s of 16bit I+Q data through 1 Gigabit of ethernet! > An external oscillator (U27 or external reference clock) is phase locked to > a reference input reference frequency clock of the AD9510. > In the USRP N210 FPGA Code can we program the divider values of AD9510 over > the SPI interface so that the output clock are not fixed? As being said, the N210 design doesn't really leave much room for this. > > We would like to be compatible with our internal Radio waveform rates and > frequencies. In this case, I recommend using a rational resampler on your host. GNU Radio comes with some -- you can try if you can match your desired sampling rate with that. With best regards, Marcus Müller [1] http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
