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[TPS659037] Confirm the shutdown method.

Guru 24520 points

Hi TI Experts.

Please let me confirm the following question.

[Question.1]
Can customer use the POWERHOLD pin as Shutdown trigger by connect the GND(LOW)?

They have a concern for reset level of POWERHOLD pin. If they used the POWERHOLD pin for shutdown, the reset level is SWORST. So, they would like to know whether there is any problem for PMIC operation to use this pin when the system is shutdown. Or shuld they use the "HWRST"?

[Question.2]

Would you please teach me the situation/objective to use the SRORST? I would like to know the timing to use the SRORST. 

If you have any question, please let me know.
Best regards.
Kaka

  • Hello Kaka,

    The PMIC will remain on as long as POWERHOLD is set high, or DEV_ON is set to "1". There is a logical OR function between these two. This means to shut off the PMIC using these pins, you must set both POWERHOLD=0V and DEV_ON="0". So if DEV_ON=1, then POWERHOLD will not shut off the PMIC. If DEV_ON=0, then POWERHOLD can be used to shut off the PMIC.

    SWORST and HWRST are different levels of reset. If you look at the register map, each register has a reset domain. SWORST registers are reset by any reset type, while HWRST registers only get reset during a POR or HWRST event. You can refer to section 5.4.7 of the datasheet for more details.

    In general, SWORST resets the sequenced resources to their default state - such as on/off, and their default voltages. This should be used when the PMIC configuration shouldn't be reset, but you want to power cycle the processor.
    HWRST will reset some of the configuration settings like open-drain/push-pull, GPIO multiplexing, interrupts, etc., and should be used when these settings need to be reset. Please refer to the register map for the reset domain for each register.

    Regards,
    Karl
  • Hi Karl,

    Thank you for your kind response.
    I could understand the POWERHOLD logic and the difference of resets.
    If I get more questions from my customer, please let me confirm them.
    Best regards.
    Kaka