i.MX7D PMIC_ON_REQ power on level

[sugiyamatoshihi]

Hi, Aurtur,

I tested PMIC_ON_REQ state of i.MX7D with SABRE board. 

I removed R350 that connected to PMIC_PWRON from Rest IC (TPS3808) output to see behavior of PMIC_ON_REQ out put when ONOFF input level.

PMIC_ON_REQ became always high when main power is up. You mentioned  when tamper pin is low, PMIC_ON_REQ should be low according to https://community.nxp.com/message/1119708 .

However, I set all tamper pins are low, but PMIC_ON_REQ became high when main power is up.

Does tamper pins are affected for PMIC_ON_REQ behavior?

Best regards,

Sugiyama

[sugiyamatoshihi]

Hi, Artur,

Thank you for explanation.

I understood.

Best Regards,

Sugiyama

[art]

When the VSNVS voltage is first applied, PMIC_ON_REQ always goes High regardless of the tamper pins state.

In the thread you're referring to, the different situation is considered. In that situation, the processor is first powered off in software (software switches PMIC_ON_REQ to Low), but the VSNVS voltage remains up and stable. In that case, generating a tamper event is one of the ways to switch PMIC_ON_REQ back High.

Best Regards,

Artur