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AM6422: AM6422 Design Clarifications: Custom Ethernet PHY Usage & Mandatory Companion Components

Daniel Cheng1
Mastermind 8275 points

Part Number: AM6422
Other Parts Discussed in Thread: SK-AM64B, TMDS64EVM

Hi TI Team,

We are currently working on a design using the AM6422 processor and would like to clarify two points regarding component selection:

1. Are there any critical hardware, software (driver), or timing/pin-strapping considerations if we use our customer's existing in-stock Ethernet PHYs for all PHY interfaces?

2. Apart from the PMIC, are there any other mandatory companion ICs, reference power schemes, or required system components for the AM6422?

 

Thanks and best regards, 

Daniel

 

  • 0
    TI__Genius 13610 points

    Hi Daniel,

    Thank you for reaching out to the TI Sitara Processors Hardware Applications support team.

    A1: There should be no issues, as far as the customer Ethernet PHYs are compatible to the ones in the TI AM64x/AM243x  EVMs and are integrated in a similar way this has been done for the CPSW3g or PRU-ICSS external Ethernet PHY (DP83867IRRGZ / DP83869HMRGZT) in the AM64x EVM (TMDS64EVM,SK-AM64B) Ethernet subsystem. 

    You may refer the schematics of the AM64x EVMs on the connectivity details.

    What is the type of xMII connections between the used AM64x MAC ports (CPSW3g or PRU-ICSS) and the external PHYs - RMII, RGMII, GMII, SGMII ?

    Is an external reference clock used or the PHY has an embedded reference clock generator.

    The PHY hardware reset pin shall be connected to a logic based on the AM64x RESETSTATz and PORz_OUT processor outputs to make sure the Ethernet PHY is appropriately reset on warm and hardware resets.  

    PHY bootstrapping configuration:

    In terms of the time-delay between the TXC and TXDATA - the AM64x CPSW3g MAC inserts such delay by default, hence the PHY bootstrapping pins shall not select any PHY added delay on the TX path. Conversely, the PHY shall add delay internally on the RX path, because the AM64x does not add it.

    For an AM64x ROM boot over Ethernet (if needed), the customer selected  PHY shall support auto-negotiation.

    Regarding software drivers I may need to forward your query to a software expert. To be able to cooperate can you please specify TI SDK type (Linux or MCU PLUS) and version used by customer ?

    Daniel Cheng1 said:
    Apart from the PMIC, are there any other mandatory companion ICs, reference power schemes, or required system components for the AM6422?

    A2: To be able to provide more accurate information, could customer provide info about the type of the Ethernet PHY chip used.  Please feel free to share over the E2E private chat, if you are not allowed to do here.

    Here is an useful FAQ regarding recommended custom board Ethernet hardware design practices:

    AM64x/AM243x recommended custom board Ethernet HW design practices

     Looking forward to customer's feedback.

    Thank you !

    Best Regards,

    Anastas Yordanov