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ahmad_zaklouta's avatar
ahmad_zaklouta
Icon for New Contributor rankNew Contributor
3 years ago

differential clock output in agilex

Hey!

I want to transmit a differential clock from 1 FPGA to another. I have been looking for a clock output buffer but didn't find it in the IP catalog. I only saw a GPIO IP.

can I use this as a clock buffer?

or Is it enough to choose a differential pair and assign the clock to the positive pin with "true differential pair" IO standard?

3 Replies

  • YuanLi_S_Intel's avatar
    YuanLi_S_Intel
    Icon for Regular Contributor rankRegular Contributor

    If you are using it as output CLOCK, it would be better for you to choose CLOCK related IP such as Clock Control Block (ALTCLKCTRL) or PLL.



    • ahmad_zaklouta's avatar
      ahmad_zaklouta
      Icon for New Contributor rankNew Contributor

      ok. Is it enough to connect the output to the positive pin of the differential pair and have the following constraint:

      set_instance_assignment -name IO_STANDARD "TRUE DIFFERENTIAL SIGNALING" -to clk_out_p
      or I should use a GPIO buffer to make it differential?
  • YuanLi_S_Intel's avatar
    YuanLi_S_Intel
    Icon for Regular Contributor rankRegular Contributor

    You can use it. However, for clock output, i will still suggest you to use dedicated CLK output pin and also clock related IP for better signal quality.