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DP83869HM: Autonegotiation Strapping for RGMII to 1000Base-X configuration

Part Number: DP83869HM
Other Parts Discussed in Thread: DP83869

Tool/software:

Following the guidelines for strapping from the following document

https://www.ti.com/lit/an/snla318/snla318.pdf

I originally planning to set

ANEG_DIS (LED_0) = 1 [Fiber Force Mode)

ANEGSEL_0(LED_1) = 1 [Configure Pin 24 as Signal Detect Pin]

LED_2 = 0 [not mentioned in the snip below so chose it randomly]

But then looking at this snip (I know it says for copper) , I am concerned that 011 will force the speed to 100M?

Mainly I am wondering what I should set the ANEG pins (ANEG_DIS, ANEGSEL_0, and ANEGSEL_1) to for RGMII to 1000Base-X mode

  • Hi Shivani,

    The Auto negotiation (ANEG) strap settings are different between copper and fiber modes. In 1000Base-X fiber mode, you would use table 5 in the linked document (Table 7-15 in the DP83869 datasheet):

    In copper mode, Auto negotiation is set based on table 16 in the linked document (7-14 in the datasheet). This can be ignored if you're operating in fiber mode.

    Mainly I am wondering what I should set the ANEG pins (ANEG_DIS, ANEGSEL_0, and ANEGSEL_1) to for RGMII to 1000Base-X mode

    Setting RGMII to 1000Base-X mode is determined by the OPMODE[2:0] strap settings. In this case, you should set OPMODE[2:0] to '001' 

    For the ANEG pins you should use table 5 from the resource you've linked. In this case, 011 would be the correct strap setting for forced fiber speed and pin 24 as signal detect.

    Let me know if you have any questions.

    Best,

    Shane