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DP83867IS: Forced 100BASE full-duplex configuration

Part Number: DP83867IS

Tool/software:

Hi Team.

My customer would like to communicate with SGMII forced 100BASE full-duplex, but the link did not established.

Please tell me the configuration to achieve this.

Is the following understanding correct?

Please tell me if there are any other important settings.

To use the same hardware with and without Auto-negotiation, they plan to enable Auto-negotiation on the strap and disable it with software.

<Forced 100BASE full-duplex config>
Register 0x0000 [6,13]=01(100Mbps)
Register 0x0000 [8]=1(Full Duplex operation)
Register 0x0000 [12]=0(Auto-Negotiation Disabled)
Register 0x0014 [6]=0(Disable SGMII Auto-Negotiation)

Best Regards,

  • Hi Atsushi-san,

    Register 0x0010 sets SGMII and RGMII enable. It is important to enable SGMII and disable RGMII.
    Bit 11 sets SGMII and bit 7 sets RGMII. 


    You can check if all the settings were set correctly by reading 0x0011 the PHY Status Register.
    Bit [15:14] is for speed selection
    Bit 13 is for duplex mode

    Please let me know how this goes. 

    Best,
    J

  • Hi J-san,

    Thank you for your reply.

    I checked register.

    0x0010 Bit[11]=1(Enable SGMII)
    0x0011 Bit[15:14]=01(100Mbps)
    0x0011 Bit[13]=1(Full Duplex)

    The customer's settings seem to be correct, so I think there may be other factors causing the link-up to fail.

  • Hi Atsushi-san, 

    Have you also checked the register 0x0010 bit 7?

    If this is set to 0, could you send us the schematic so we can review the overall configuration of the PHY to provide you a possible solution?

    Best,
    J

  • Hi J-san,

    Thank you for your reply.

    I checked the the register 0x0010 bit7=0(Normal operation).

    I'll send you the schematic via private massage later.

  • Hi Atsushi-san, 

    I received your schematic. 

    All the important configurations are set correctly. 

    I notice that the PHYs can link up with certain devices and it can link up with all partners when auto-negotiation is enabled.

    Could the customer enable auto-negotiation, but force to advertise only full-duplex mode at 100M?
    And could they check if the windows 10 devices support 100M Full duplex mode? When forcing the PHY to 100M full duplex mode, the link partner must be in the same mode, or the link will not be established. 
    Please let me know. 

    Best,
    J

  • Hi, I will be closing this ticket due to inactivity. 

  • Hi J-san,

    I'm sorry for the late reply.

    I haven't received any feedback from the customer yet about whether your solution resolved the issue.

    I agree with closing this case.

    If there is any, I will create a new case.

  • Thank you!