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DP83867IS: Auto-negotiation

Shuji Ishiwata
Mastermind 7815 points
Part Number: DP83867IS

Tool/software:

Hi All,


I have a question about auto-negotiation on the DP83867.

Could you please tell me what equipment and methods I can use to check if auto-negotiation is working properly?

I can check if auto-negotiation is working properly through the registers, but I would like to know how to check it in real time.

How does TI evaluate auto-negotiation?


Best Regards,
Ishiwata

  • 0
    TI__Expert 6405 points

    Hi Ishiwata, 

    As you mentioned, the status of auto-negotiation, along with any errors/problems encountered, can be read in the device registers, as described by the IEEE802.3 guidelines. This is what we use to validate the auto-negotiation status as well. 

    All our PHYs have been validated for this IEEE standard, and have been found to follow it. 

    Checking auto-negotiation through the signals exchanged would be a more complicated process requiring in-depth knowledge of the signal timing, packet structure, the devices being linked and a myriad of other things outlined in the IEEE802.3 standard, specifically clause 28. I don't believe there is a tool to do this task more efficiently. 

    Is there a particular reason why you do not want to use the registers to check the status of auto-negotiation? 

    Best,

    Vivaan

  • 0 in reply to Vivaan Jaiswal
    Mastermind 7815 points

    Hi Vivaan,


    The DP83867IS is connected to another company's Ethernet device. The register information of that device cannot be read.

    I would like to verify the connected Ethernet device to prove that the DP83867IS's auto-negotiation operation is correct, so I am looking for a device to measure it.

    Could you please tell me what device I can use to measure this?


    Best Regards,
    Ishiwata

  • +1 in reply to Shuji Ishiwata
    TI__Expert 6405 points

    HI Ishiwata, 

    Auto-negotiation happens through a series of fast link pulses, or FLPs. These can be measured on an oscilloscope and can be decoded to see what information these devices are sharing with each other. Contact your scope vendor to see if they have a FLP decoding software available to make that part easier. 

    However, if you are only trying to extract the basic information about the link partner, register 0x05 in our PHY has the information about supported link speeds, duplexity, etc that the link partner has sent as well. 

    Best,

    Vivaan