Post Go back to editing

DAQ2 latency for streaming

Category: Hardware
Product Number: AD-FMCDAQ2-EBZ
Software Version: 2019_r2_220331


I am doing some experiments with FMCDAQ2 and the HDL reference implementation (ZCU102 board).

I found the streaming latency from HDL via AD9144 - loopback cable - AD9680 to HDL to be about 400 ns. Is this an realistic value?

The time is measured between axi_ad9144_tpl (outgoing) and axi_ad9680_tp (incoming), so there is no FIFO involved.

Thank you, and best regards,


Top Replies

    Jul 25, 2022 in reply to EHeinz689 +1 verified

    Hello  ,

    In my opinion the latency you measured is a reasonable one, as an example we measured the same 400ns round-trip TPL latency for another project with ad9081_fmca_ebz configured on the default…

  • Hello Erik!

    For this setup are you using no-os or Linux? Also how did you measure the delay between the two transport layers? Have you done any additional changes or are you using the original code from the 2019_r2 branch?

    Meanwhile I will try to simulate the JESD path for this block design and try to calculate the delay between the two TPLs.

    I will let you know what I'll get on my side! Kind regards!


  • Hello Filip,

    I am using the Linux environment, but I think this shouldn't matter here.

    I have modified the 2019_r2 HDL reference code a bit, but I didn't change the axi_ad9144_tpl -> axi_ad9144_jesd -> util_daq2_xcvr and util_daq2_xcvr -> axi_ad9680_jesd -> axi_ad9680_tpl parts, so the JESD parameters are still original.

    Basically, I introduced clocked gates before axi_ad9144_tpl and after axi_ad9680_tpl to be able to send and receive boxcar signals. AD9144 outputs are connected to AD9680 inputs. If I start both gates at the same time, I can see the delay between RX and TX in the output signal. This delay should include both JESD interfaces, the DAC and ADC itself, and the travel time on the cable.

    My question was just, what order of delay could be expected here and if 400 ns are a reasonable value.

    Best regards,


  • Moved the thread to the appropriate forum

Reply Children
No Data