Hi Damon, The X310 cannot handle 200 MS/s on both channels simultaneously through the DmaFIFO. The bandwidth of this RAM cannot handle that much data simultaneously entering & leaving. It *may* be possible to achieve this with a different FPGA image that has 2 FIFOs on the FPGA (noc_block_axi_fifo_loopback) fabric but I don't know for certain. The default N310 image uses these rather than the DmaFIFO to achieve 4x100MS/s. Rob
On Wed, Jun 24, 2020 at 1:49 PM Marcus D. Leech via USRP-users < [email protected]> wrote: > On 06/24/2020 01:46 PM, guowang qiu via USRP-users wrote: > > Hi all, > > > > I am trying to set my USRP X310 to send out signals in burst mode at > > 200Msps sample rate on two channels. My target is sending out bursts > > of 100ms without underflow. > > The OS is Ubuntu 18.04, UHD version v3.15.0.0, DPDK is used in the > > test. The CPU is set to 4.2GHz. > > The X310 is connected to the host by dual 10 Gigabit Ethernet. > > > > sudo /usr/local/lib/uhd/examples/tx_bursts > > > --args="type=x300,use_dpdk=1,addr=192.168.30.2,second_addr=192.168.40.2,send_frame_size=8000,num_send_frames=512" > > > --repeat --dilv --nsamps=20000000 --channels=0,1 --rate=200e6 > > > > If nsamps is set to 100000, there is no U printed. But if nsamps is > > large than 120000, the terminal prints a lot of U. > > Question 1: the depth of DMA FIFO is 32MB by default, I guess there > > should be 8M samples stored in the DMA FIFO, why it seems that it just > > store 100K samples? > > Question 2: is there anything I could do to achieve my goal? > > > > Best regards, > > Damon > > > > > I don't know about the performance question, but there's ZERO reason to > run that example under 'sudo'. > > > > _______________________________________________ > USRP-users mailing list > [email protected] > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com >
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