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TDA2PXEVM: TDA2Px EVM board software warm reset will not reset LP87565?

Tao Han
Expert 6465 points
Part Number: TDA2PXEVM

Hi Experts:

We are working with customer review our TDA2P EVM design.

When software warm reset trigger or PORz signal trigger, TDA2P pin D23 RSTOUTN will trigger TPS65917 pin 13 (GPIO_1 OTP configure as reset in).

It will successful reset TPS65917 return to OTP default voltage output. But LP87565 will not be reset, The VDD_MPU and VDD_GPU power rail will keep to reset start voltage. We think this design is not right, it can not match snvu590.pdf guide introduced boot mode voltage.

Can you help us double check the LP87565 whether been reset when TDA2P PORz/warm reset triggered?

Best Regards!

han Tao

  • 0
    TI__Guru 52525 points

    The LP87565 device does not support a 'warm reset input' similar to that on the TPS65917 device.  The TPS65917 warm reset input is typically critical as the SD card voltage must be reset to the default voltage for booting.  The remaining power supply voltages (including LP87565) will remain as they were prior to the warm reset event.

  • 0 in reply to Robert Eschler
    TI__Expert 6465 points

    Hi Robert:

    Whether this will be have problem at warm reset boot?

    Because DM  Table 5-3 said that boot mode need > 1.11V power supply. but when A15 work at OPP_NOM mode, the VDD_MPU voltage is maybe < 1.0V.

    At this time software trigger warm reset signal, LP87565+TPS65917 keep the power supply voltage is OPP_NOM, it below than DM request.

    Old TPS659039 PMIC when warm reset the output voltage will return to default setting as swcu175c.pdf user guide introduce.

    So J6P EVM board warm reset whether have risk can not successful boot up?

    Best Regards!

    Han Tao

  • 0 in reply to Tao Han
    TI__Expert 6995 points

    During development of the J6Plus EVM, TI SW team made an assessment on the value of warm reset & decided that this operation had minimal value. Please kindly refer to note #5 captured on the J6Plus EVM PDN diagram that clearly states the following:

    5. This PDN does not support a “Warm Reset” that can be initiated by SW running on SoC by asserting the RSTOUTn ball. The LM87xxx PMIC family does not support this type of SW reset functionality that is supported by the TPS659xx PMIC family.

  • 0 in reply to Bill McCracken
    TI__Expert 6465 points

    Hi Bill & Robert:

    Thanks clarify it to me.

    Because customer when MCU probe TDA2P software hung, it will pull down PORz and restart TDA2P.

    Very low probability some board can not successful boot up i am worry that it have relationship with PMIC do not reset to the default voltage.

    It is clear that J6P/TDA2P EVM board warm reset will not trigger LP87565+TPS65917 output voltage return to the default value.

    Best Regards!

    Han Tao

  • 0 in reply to Tao Han
    TI__Guru 54512 points

    Tao,

    If the PMIC was at a safe AVS voltage prior to reboot, then the SoC should be able to boot just fine at that same voltage. 

    Regards,

    Kyle