2021-07-01 05:12 AM
my board have not use pmic and i use poweroff close the board. it will reboot and tf-a report reset reason (0x814) for NRST
2021-07-01 05:14 AM
2021-07-01 05:53 AM
Hi,
If you expect to poweroff the supplies, I think you have provisioned some external HW for that (to power off and able to power on again with e.g. a button or a request from RTC/TAMP). Which interface you have for that (I2C, GPIOs, ?)
I think TF-A should be adapted to your HW.
Regards.
Patrick
2021-07-01 06:33 PM
i have two version hw. ver.1 can use poweroff to close, but ver.2 can't both have same power support. ver.2 use poweroff and it will be go into bor_rst and reset the board.
2021-07-01 11:21 PM
Hi,
When you shutdown supplies including VDD, it is normal behavior to get a NRST=0 when VDD became too low. This cannot be avoided.
For example, if you use a GPIO output to start an HW shutdown to your supplies, the NRST=0 will put back all GPIOs to high-z which might put the power supplies back to ON state.
It is up to your board HW to ignore this and continue the HW shutdown sequence until complete platform power-off.
it is usually tricky to have such power on/off HW mechanism reliable. STPMIC1 is more handy for doing this.
Regards.