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TMDS64GPEVM: SERDES Lines

Mahendra A G
Prodigy 60 points

Part Number: TMDS64GPEVM

Hi,

I am working on a custom board using AM6442ALV SOC, and i am not using most of the interfaces available on the SOC, so do i need to feed the power to SERDES, ADC, MMC1 of SOC, as i am not using these interfaces and do i need to provide any PU/PD termination for the unused SOC pins?

Thank You.

  • 0
    Prodigy 60 points

    I am Looking what should be connected specific to VDDSHV5, as i have connected CAP_VDDSHV_MMC1 to VSS (as per datasheet recommendation)

  • 0 in reply to Mahendra A G
    TI__Expert 3340 points

    Hi Mahendra,

    Please see Datasheet Section 6.5 "Connections for Unused Pins" for the first part of your question, as it lists specific recommendations for SERDES and ADC. (as well as others)

    The rest of the question is answered by the note on page 125:

    "All other unused signal balls with a Pad Configuration Register can be left unconnected with their multiplexing mode set to GPIO input and internal pulldown resistor enabled.

    Unused balls are defined as those which only connect to a PCB solder pad. This is the only use case where internal pull resistors are allowed as the only source/sink to hold a valid logic level.

    All other unused signal balls without a Pad Configuration Register can be left unconnected."

    So for VDDSHV5, as long as the balls themselves are unused, you should be fine to have the other signals being used just with the internal pulldown, but if the balls are not "unused" as defined above, external pulldown resistors will be required.

    Please let me know if that helps clarify your issue.

    Best,

    Andrei

  • 0 in reply to Andrei Aldea
    Prodigy 60 points

    So do i have to connect Pull down resistors to VDDSHV5?

  • 0 in reply to Mahendra A G
    TI__Expert 3340 points

    Only if you have traces coming off any of the pads and they are "used" as defined above.