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AM625: Connections between TPS65219 and AM62X

Part Number: AM625
Other Parts Discussed in Thread: TPS65219

Hi TI colleagues.

I saw there were some recommended connections between PMIC TPS65219 and Main domain of AM62X as below:

PMIC        AM62x

--------------------------

VSEL        GPO

MODE      RESETSTATZ

STBY        GPO

---------------------------

Could you please help to explain the reason that connects with Main domain? or the use cases?

If our use case is that Power control only deployed on MCU domain, shall we map these Pins to MCU domain?

Thanks !

BR

Weicheng Li

  • Hello Weicheng Li

    Thank you for the query.

    I guess using the RESETSTSTz ensure the required functionality is executed during warm as well as cold reset.

    MODE      RESETSTATZ

    If our use case is that Power control only deployed on MCU domain, shall we map these Pins to MCU domain?

    Let me reassign to an expert.

    Regards,

    Sreenivasa

  • These signals should remain connected as recommended in the PMIC app note.  The VSEL pin is used for SD card IO select.  STBY is used for low power modes and connected to the PMIC_LPM_EN0 signal on the SoC, which will control PMIC sleep modes based on the activity on the SoC.  The RESET is connected to the MAIN domain reset status signal, and provides warm or cold reset on the PMIC (configurable with NVM on the PMIC) when the MAIN domain is reset. 

    Regards,

    James 

  • Hi James

    thanks for the reply, 

    so basically even if the power control SW deployed in MCU only, still need to connnect these pins with Maindomain?  I think this kind of design needs IPC to support some power control  functions, this method increased the complexity of design I believe.

    and another consideration is that when the SOC transited into MCU only mode, MCU cannot reach these Pins afterwards.

    BR

    Weicheng

  • so basically even if the power control SW deployed in MCU only

    Is this software was developed by you, or is this part of TI SDK?  Any custom modification of the PMIC interface would have to be analyzed to ensure proper functionality.  I'm not saying it can't be done, just that a lot of work went into the proposals in the app note, and any deviation from that would need to be tested thoroughly.

    As for the specific signal you are asking about, i have the following questions:

    -the VSEL is used for SD IO card select.  The SDMMC interface is in the MAIN domain, so this is why this signal is also sourced from the main domain.  What is the use case to control it from the MCU domain?  Typically this is something that changes during SD card operation when needing to switch from 3.3V to 1.8V for high speed operation, and back to 3.3V when the card needs to be reset.

    -STBY is connected to specific functionality of the processor of the PMIC_LPM_EN0 signal.  This is actually controlled by the DM logic in the SoC.  Controlling it any other way would remove its control from the deep sleep logic in the device.  So depending on how you are implementing low power in your application, this would need to be tested.

    -the reset could possibly be controlled by MCU_RESETSTATz.  You would have to check the functionality of this signal in the PMIC to see if it meets your needs with the reset from the MCU domain.

    Regards,

    James

     

  • Is this software was developed by you, or is this part of TI SDK? 

    This SW was developed by our SW colleagues, I don't think it comes from TI SDK.

  • Ok, then just be sure to comprehend the whole power solution when making any modifications to the suggested connection.

    Regards,

    James

  • Hi James

    According to your replies my understanding is that the power management SWC also deployed on main domain in your TI SDK? could you please share a brief introduction?

    thank you!

    Regards

    Weicheng Li