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DP83867IS: DP83867IS: DP83867ISRGZ's LAN Compliance test is FAIL(Distortion), EMC is FAIL

Hyoungrae Ryu
Prodigy 40 points
Part Number: DP83867IS

Tool/software:

Hi.

We tested it using a new board and register.

There are 2 problems.(attachment pdf file)

(1) 1000 Base-T, Point Template Test(w/ Disturbing Signal)

     -.Differences in performance by register(1000Base-T mode reg. 0x0140)

     --> Successful when inserting register, failed when removing register

(2) 1000 Base-T, Transmitter Distortion(w/ Disturbing Signal)

     --> Workaround if only a particular pair fails (ex. D pair is fail)

(3) There is a 125MHz(EMC) noise problem. We need a solution.

4338.Eth0-1000-issue.pdf

please check it

[Share existing questions]

DP83867IS: Review the MDI interface line's circuit

  • 0
    TI__Mastermind 18851 points

    Hi Hyoungrae,

    Thank you for submitting your query. I'll gladly assist you in resolving the Compliance and EMC issues you are facing. As a heads up, both of these issues can be affected by many factors. I want to begin looking at these very carefully, starting from a very high level and slowly closing in on the issue. Typically I would like to work on one of these issues at a time. For now, I have a few questions that I would like to clarify on below.

    1. Just to confirm, when using Reg 0x0 = 0x0140, the test passes with no issues correct? This is expected. Please see this FAQ and confirm if this is the script you are using. Hopefully this is the case and everything is passing on your board.
    2. Distortion is a little tricky, and we have seen varying results depending on which scope and software version being used. In the Eth0-1000-issue document, could you share the script that was used to configure the DP83867 prior to running the test?
    3. From the E2E you linked, I see you are using SGMII. The 125 MHz is probably coming from the MDI (cable side), what kind of cable are you using (shielded or unshielded)?
      1. We have recently release a comprehensive EMC appnote, could you take a look at it and see if it helps debug the issue further?
        1. https://www.ti.com/lit/an/snla466/snla466.pdf

    Regards,

    Alvaro