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Original question:

DP83867IR: MDIO and MDC pin query

DP83867E: 1000BASE RJ-45 connection with SGMII and without MDIO connection

Kento Adachi
Expert 7155 points

Part Number: DP83867E

Hi experts,

My customer is looking for an ethernet PHY which can support following requirements.

  1. 1000BASE communication through RJ-45
  2. SGMII
  3. No MDIO connection

Below is my questions.

  1. When I see DP83867E datasheet, it can support all of the three requirements by using auto-negotiation and appropriate strap configuration, is it correct?
  2. As customer does not use MDIO/MDC pins, what is the recommended termination? It seems general recommendation is to pull them down. Any recommended pull-down value? image.png

3. What is the strap configuraiton needed to achieve the three requirements above? Below is my understanding and questions.

  • RX_D0, RX_D1...Depending on PHY Address customer wants to use. RX_D0 and RX_D1 must have the same strap configuration
  • RX_D2, RX_D3...Same as RX_D0, RX_D1
  • RX_CTRL...MODE 3 to enable auto-negotiation
  • GPIO_0/1...Any requirements?
  • LED_2...Any requirements?
  • LED_1...Any requirements_
  • LED_0...SGMII enable must be 1 (MODE 2 or MODE 4)

Regards,

Kento

 

  • +1
    TI__Mastermind 26771 points

    Hi Adachi-san, 


    Kento Adachi said:
    When I see DP83867E datasheet, it can support all of the three requirements by using auto-negotiation and appropriate strap configuration, is it correct?

    Yes, this is correct. 


    Kento Adachi said:
    As customer does not use MDIO/MDC pins, what is the recommended termination? It seems general recommendation is to pull them down. Any recommended pull-down value?

    There is no recommended pull-down value as long as this is pulled down to GND. 


    Kento Adachi said:

    What is the strap configuraiton needed to achieve the three requirements above? Below is my understanding and questions.

    • RX_D0, RX_D1...Depending on PHY Address customer wants to use. RX_D0 and RX_D1 must have the same strap configuration
    • RX_D2, RX_D3...Same as RX_D0, RX_D1
    • RX_CTRL...MODE 3 to enable auto-negotiation
    • GPIO_0/1...Any requirements?
    • LED_2...Any requirements?
    • LED_1...Any requirements_
    • LED_0...SGMII enable must be 1 (MODE 2 or MODE 4)

    For LED_1, please strap to mode 1 or 2. 
    For LED_0, mode 2 or 4 depending on if the customer will implement mirror mode. 
    LED_2 and GPIO_0/1 can be kept to default strapping option. 
    Otherwise, your understanding is correct. 

    Best,
    J

  • 0 in reply to J
    TI__Expert 7155 points

    Thank you J!

    Regards,

    Kento