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why rx_is_lockedtodata is not set to 1 after the work of the controller?


I implement the 10GBase-R protocol on the transceiver native phy. I use a reset controller in the my project. After power-up or reset, rx_is_lockedtodata in not asserted and my receiver in reset state always. Arria 10 GX

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As I understand it, you observed that the rx_is_lockedtodata signal of the A10 Native PHY is not asserting. For your information, the rx_is_lockedtodata not asserting indicates that the CDR is unable to achieve lock to incoming data.


The following are some of the general causes for CDR unable to achieve lock for your reference to look into:


  1. No valid data/signal present at the RX pin
  2. RX analog reset not released
  3. Signal integrity of the incoming signal not meeting RX requirement
  4. ppm difference between the incoming data vs CDR local refclk exceed the threshold setting of CDR
  5. Issue with CDR local refclk ie incorrect frequency, signal integiry issue, no valid signal presence.

You can try to look into the above areas to see if can spot any anomaly.


Thank you.

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