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host's avatar
host
Icon for Occasional Contributor rankOccasional Contributor
5 months ago
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Multi-rate Ethernet valid signal behavior

I'm working with the 1G/2.5G/5G/10G Multi-rate Ethernet PHY IP Core on an Arria V device.
https://www.intel.com/content/www/us/en/docs/programmable/683171/current/introduction-to-the-protocol-specific.html#joc1445401896251


I fixed my IP to 2.5G and have a question about the gmii16b_rx_dv signal.
The datasheet explains that this signal marks which of the 2 bytes are valid:

Is it possible for one of the bits of gmii16b_rx_dv to be '0' in the middle of a packet ?
Or it can happen ONLY in the last byte ?

Ethernet
  • paveetirrasrie_Altera's avatar
    paveetirrasrie_Altera
    4 months ago

    Hello,


    Good day.

    The lower byte (gmii16b_rxd[7:0]) contains the valid data.

    Hope this answer your query.


    Regards,

    Pavee


4 Replies

  • paveetirrasrie_Altera's avatar
    paveetirrasrie_Altera
    Icon for Frequent Contributor rankFrequent Contributor
    4 months ago

    I’m glad that your question has been addressed, I now transition this thread to community support.

    If you have a new question, feel free to open a new thread to get the support from Altera experts.

    Otherwise, the community users will continue to help you on this thread.

    Thank you.


    Regards,

    Pavee


  • paveetirrasrie_Altera's avatar
    paveetirrasrie_Altera
    Icon for Frequent Contributor rankFrequent Contributor
    4 months ago

    Hello,


    Good day.

    The lower byte (gmii16b_rxd[7:0]) contains the valid data.

    Hope this answer your query.


    Regards,

    Pavee


  • paveetirrasrie_Altera's avatar
    paveetirrasrie_Altera
    Icon for Frequent Contributor rankFrequent Contributor
    4 months ago

    Hello,


    It can happen only in the last word of a packet.

    In the middle of a packet, both bits of gmii16b_rx_dv should always be '1'.

    Hope this answer your query.


    Regards,

    Pavee


    • host's avatar
      host
      Icon for Occasional Contributor rankOccasional Contributor
      4 months ago

      Thanks for the input.

      When it does happen, which of the bytes will contain valid data [15:8] or [7:0] ?