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DP83822IF: DP83822IF link not up

VSS
Prodigy 160 points
Part Number: DP83822IF

Hello,

We are using the DP83822IF in our design.  We can't get the media side link to come up.  We tried the various loopback mode in the PHY and here are the results;

BIST and PCS Input Loopback, PRBS checker is locked and there is no error

BIST and PCS Output Loopback, PRBS checker is locked and there is no error

BIST and Digital Loopback, PRBS checker is locked and there is no error

We then proceeded to disable the loopback and used an external loopback plug.  PRBS check is never locked or synced.  I would presume that the receiver doesn't see the packet?

We also don't get the link up with the loopback plug.  All the above were tried with auto-negotiation disabled and the speed set to 100M.

Below is the schematics of the media side connection.  Requesting to review this section and let us know if there are any issues.  Note we have used integrated magnetics with part number JX00-0027NL.  The magnetics has the same specification as the recommended list in the datasheet.

Thanks in advance.

Vijay

  • 0
    TI__Genius 9920 points

    Hi Vijay,

    Please allow me more time to review the schematic. Is there a reason you have Auto-negotiation disabled? Were you also able to test the Far End Reverse Loopback? 

    Thanks,

    Cecilia

  • 0 in reply to Cecilia Reyes
    Prodigy 160 points

    Hi Cecilia,

    Auto negotiation is disabled as per TI recommendation in the datasheet for testing the internal loopback modes.  For external loopback, we wanted to reduce as much complexity as possible.  From an application point of view, we can still use auto negotiation.

    No, we did not test the Far End Reverse Loopback since the line side link is not yet up and we can't communicate with the link partner.

    Look forward to your comments on the schematics.

    Thanks,

    Vijay

  • 0 in reply to VSS
    TI__Genius 9920 points

    Hi Vijay,

    Apologies on the delayed response. What is the part number for your XI clock? Are you using a 50 MHz oscillator? Have you ensured that it meets the ppm requirements? 

    I reviewed your schematic and there looks to be no glaring issues on your design.