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DP83867E: No sgmii link , but "SGMII Page Received "

Seda Demirhan
Prodigy 105 points
Part Number: DP83867E


hi,

I use DP83867E phy.  I want to communicate phy and mac using SGMII interface. I enabled SGMII in phy. I read register 0x0037 and its value is 0x0002 . This means 0 = SGMII Auto-Negotiation process not complete but 1= SGMII page has been received. But i do not understand, SGMII setting is correctly done in phy interface or vice versa. What does mean "SGMII page has been received" ? Where i wrong Fhy interface or Mac interface(Switch) or both of them?

Thank you for your time.

Best Regars,

Seda Demirhan

  • 0
    TI__Mastermind 19780 points

    Hi Seda,

    When auto-negotiating, the PHY and MAC exchange information on the link settings.  The PHY sends information and the MAC responds with an acknowledge bit.

    If you aren't establishing an SGMII link, is your RX_CTRL pin strapped in mode 3?

    Please see the Strap Configuration section in the DP83867E datasheet.  If RX_CTRL is not strapped in mode 3, follow the note in the table about clearing bit[7] of register 0x31.  This is the most common cause of SGMII link not being present.

    Please also provide a schematic of your DP83867E solution for us to review for other issues.

    Best Regards,

  • 0 in reply to Rob Rodrigues
    Prodigy 105 points
    Hi Rob,

    Thanks for your reply. I have some problem using DP83867e.
    Firstly, I use RX_D0 strap pin and RX_D0 is strapped in mode 3( RX_D0 pin strapped in mode 3). However i realized that i have to use mode 2 for strap pin of RX_D0 . When i changed Rx_D0 strap pin to mode 2(RX_D0 pin strapped in mode 2), i did not access DP83867e using MDIO interface. But when the MDI side of the PHY is connected to a PC through a CAT-5 ethernet cable, the MDI side is auto-negotiated to 1000Mbps with no problems. After that, accordingly your respond i realize that RX_CTRL is strapped in mode 1. I changed RX_CTRL strap pin mode. RX_CTRL is strapped in mode 3. Then the MDI side of the PHY connected to a PC through a CAT-5 ethernet cable is not auto-negotiated. The link is not up.
    Why that happen? Why did i not access DP83867e using MDIO interface? Why is auto-negotiated not when i set RX_CTRL to mode 3?
    Do you have any recommends?


    Thank you for your time.

    Best Regards,

    Seda Demirhan
  • 0 in reply to Seda Demirhan
    Prodigy 105 points
    Hı Rob,
    Before I change the mode of strap pins, I set sgmii enable bit. Rx_ctrl pin is not connected in semantic. And then I clear bit[7] of register 0x31. But nothing happen. Why all of this happen. I am very confused I don't know what should I do?

    Best regards,
    Orda
  • 0 in reply to Seda Demirhan
    TI__Mastermind 19780 points
    Hi Orda,

    I need to see a copy of your schematic to really help you. You can send me a private message if you do not want to share it here.

    Lets treat the three topics separately: MDI auto-negotiation, MDIO communications

    For auto-negotiation. If you strap RX_CTRL into mode 3, using a 5.76k pull-up and a 2.49k pull-down, you will auto-negotiate with the PC. If you are not auto-negotiating, then RX_CTRL is in mode 2 or 4. Please verify your strapping is correct.

    For MDIO communications, if you strap RX_D0 to mode 3, the PHY ID = 0x2. If you then change RX_D0 to mode 2, your PHY_ID changes to 0x1. Your processor needs to know this.

    Best Regards,
  • 0 in reply to Rob Rodrigues
    Prodigy 105 points
    Hi Rob,

    I changed strap pin of Rx_CTRL. Rx_CTRL is strapped mode 3 and then i read bit[7] of register 0x31. This bit[7] value is read "1". Is this normal? Only when i strapped Rx_CTRL to mode 1 or mode 2, should i clear bit[7] of register 0x31? or Whenever i read bit[7] of register 0x31 "1", should i clear bit[7] of register 0x31?

    Thank you for your time.

    Best Regards,

    Seda
  • 0 in reply to Seda Demirhan
    Prodigy 105 points
    Hi Rob,

    When I read register of 0x31, its value is 10B0. I checked data sheet of do83867 and I saw that it is reserved and it should be "0". Why do I read value register of 0x31 is "10B0" ?
    Thank you for your time.
    Best regards.
    Orda