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K606's avatar
K606
Icon for Contributor rankContributor
1 year ago
Solved

Agilex 5 GTS PMA/FEC Direct Loopback

Say I need to connect an oscillating component (with parallel data) to the GTS from the fabric, and then loop it back to via serial in fabric, and then read the output parallel data. To set this u...
Ethernet
  • CheepinC_altera's avatar
    CheepinC_altera
    1 year ago

    Hi,


    Thanks for your update.


    Based on your description, it seems your datapath is structured as follows:


    Oscillator → tx_parallel_data input → GTS PHY → rx_parallel_data output → DMA → HPS


    To achieve this setup, you can enable the Parallel Loopback path (Path B). This configuration allows the parallel data fed into the TX interface to be directly routed to the RX interface, bypassing the serializer, deserializer, and CDR blocks.


    This approach should help simplify your testing or validation process without involving the full high-speed serial path.


    Let me know if you need further clarification or assistance.


    Best regards,

    Chee Pin


CheepinC_altera's avatar
CheepinC_altera
Icon for Regular Contributor rankRegular Contributor
1 year ago

Hi,


I noticed that there seems to be some issue with the image uploading. Just to clarify, I am referring to the PMA-transmitter-to-receiver parallel loopback (TX2RXPAR) as in the GTS Transceiver PHY User Guide: Agilex 5 FPGAs and SoCs -> "Figure 21. PMA Loopback Modes". Sorry for the inconvenience.


  • CheepinC_altera's avatar
    CheepinC_altera
    Icon for Regular Contributor rankRegular Contributor
    1 year ago

    Hi,

    Just following up to check if you have any further inquiries related to this topic that I can assist with. If everything has been addressed, I’m planning to close the case shortly.

    Please feel free to let me know if there's anything else you'd like to discuss. Thank you!