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DP83867CR: RGMII vs SGMII and Device P2P Interoperability

Darren (FAE)
Expert 5483 points
Part Number: DP83867CR
Other Parts Discussed in Thread: DP83867IS, DP83867IR,

DP83867IS(RGZ-48) can be both SGMII or RGMII based on strap/register settings.
So if the device was configured for RGMII-mode, would you be able to replace it with DP83867IR(RGZ-48)?

The pin layout seems identical (for RGMII use-case), and the register settings for "IR" device just has "Reserved" for all SGMII-related bits...it looks completely P2P compatible...

Can you confirm for me the following?

External Pinout:

1) Are DP83867IS (CS) and DP83867IR (CR) physically P2P compatible, if both are used for RGMII-interface? (external connections would be identical)

Internal Settings / STRAP config

2) All DP83867IS register settings related to SGMII seem to be "Reserved" bits in DP83867IR.
But, I noticed some registers like RGMIICTL2 are a little different (DP83867IS has a few more options)

Is it still possible, with minimal software modifications, to have a hardware P2P setup, and depending on the register settings used, also a software P2P configuration?

Darren

  • 0
    TI__Guru**** 192199 points

    Hello Darren, 

    Thank you for the query. 

    If would help to check if customer is configuring RGMII Control Register 2 (RGMIICTL2) with the IS device. 

    Are DP83867IS (CS) and DP83867IR (CR) physically P2P compatible, if both are used for RGMII-interface?

    Did you mean functionally compatible ?

    As you work on getting these answers, i expect to have some additional info to you in the next 2-3 days.

    Regards,

    Sreenivasa

     

  • 0 in reply to Kallikuppa Sreenivasa
    TI__Expert 5483 points

    Hi Sreenivasa,

    [1]
    Is RGMIICTL2 the only register where "it would help to check" on...? (Not familiar enough with other register addresses to know)

    [2]
    Yes, functionally compatible (in RGMII application) (keep same schematics for DP83867IS in RGMII mode, and use DP83867CR in RGMII mode)

    Darren

  • 0 in reply to Darren (FAE)
    TI__Guru**** 192199 points

    Hello Darren, 

    Thank you for the message. 

    The IR 48-pin version is drop-in replaceable with the IS, with the exception that they will need to change their MAC interface connection from SGMII to RGMII (This is required In case customer is using register to enable the MAC interface - reference register PHY Control Register (PHYCR), Address 0x0010).

    Regards,

    Sreenivasa

  • 0 in reply to Kallikuppa Sreenivasa
    TI__Expert 5483 points

    Hi Sreenivasa,

    Appreciated! Quick follow-up:

    We actually want to replace DP83867IS with DP83867CR.
    The difference in "I" to "C" is just operating temperature, and the "C" version doesn't have some max/min specs listed, right?

    So, DP83867CR(RGZ) is drop-in replacement for DP83867IS(RGZ),
    as long as DP83867IS's register settings / strap configs are for RGMII MAC interface, right?

    No other register settings to concern ourselves with besides RGMIICTL2?

    Darren

  • 0 in reply to Darren (FAE)
    TI__Guru**** 192199 points

    Hello Darren,

    That is right.

    With change in operating temperature, if customer has concerns on operation/performance over temperature, this would need to be tested.

    Regards,

    Sreenivasa