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LP873220: I2C reset

Oba
Genius 15970 points
Part Number: LP873220
Other Parts Discussed in Thread: LP87332D

Hello,

My customer is using LP873220 and LP87332D with AM57x.
They are checking possible abnormal cases and have a question for I2C interface of LP873220 and LP87332D.
If something failure happens during the I2C communcation, like the host stops the SCLK during the PIMC outputs low (like ACK) on SDA.
In this case, I think the PMIC continues to hold SDA line low. Do both PMICs have a timeout function to avoid holging the SDA line forever?

If they don't have a timeout function, is there any way to reset I2C communcation (stop PMIC holding SDA line low)?

Regards,
Oba

  • +1
    TI__Genius 10662 points

    Hi Oba,

    What is the status of the other input levels when this is being seen? Is V(vana) < VANA(uvlo)? Is there a way for you to disconnect the I2C lines from the primary and secondary devices to try and see specifically what device or end (either primary or secondary) is causing this? Is the SCL being held low the whole time too? Are you waiting 1.2ms before writing or reading data from the device after power up?

    If the SDA line is going low thus you are unable to write or read to the device (from external device or the device), then trying to reset I2C communication may need to be done through resetting the device by the VANA supply voltage fall below UVLO threshold level, and then driven above it, essentially restarting the device.

    Thanks,
    Field

  • 0 in reply to Field Tolson
    TI__Genius 15970 points

    Hello Field,

    Thanks for your reply.
    They actaully are not facing any issue related to this topic.
    This is just a possible worst case study.

    The assumed condition is just SCK stopping. So supply voltage remains within the recommended operating condition.

    I understand there is no way to reset without the power cycle.

    Regards,
    Oba