AM5728: PMIC Reset During Reboot

allen.zhang

Part Number: AM5728

Hi,

I have the same problem as this post：

https://e2e.ti.com/support/processors/f/791/t/534394?tisearch=e2e-sitesearch&keymatch=reboot

For some reason, I need to reset SMPS and LDO during linux reboot.
We have followed the AM5728 reference design and the reset outn pin is connected to the PMIC NRESWARM pin.
When rebooting, I can see the PMIC NRESWARM and RESET_OUT asserted low then asserted high, but LMPS and LDO's power state never be toggled or changed.
WR_S bit in the SMPSx_CTRL register or the LDOx_CTRL register is 0, and MODE_ACTIVE bit is 0x3(Forced PWM).

How do I reset the voltage of LMPS and LDO?

Thanks，

allen

over 4 years ago

0 Ahmad_Rashed over 4 years ago

TI__Genius 13567 points

You seem to be confused about the expected behavior. The PMIC does receive the reset command and it will change any SMPS and LDO values back to default voltages if the software has ever changed from the default. However it does NOT turn off and turn on again.

0 allen.zhang over 4 years ago in reply to Ahmad_Rashed

Intellectual 365 points

Hi Ahmad,

Is there a way to turn off and on again the SMPS and LDO when pmic receiving reset command? Like the ACT2SLP and SLP2ACT queues.

Thanks

0 Ahmad_Rashed over 4 years ago in reply to allen.zhang

TI__Genius 13567 points

If you wish to power cycle a specific supply it is possible to use I2C commands with the PMIC. However it must be a supply not shared by the AM57x. Only the ACT2OFF sequence will power off the supplies and I don't believe we support sleep modes on AM57x family.

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AM5728: PMIC Reset During Reboot