We use a GPIO to switch external hardware on/off with an external pull up. At the moment we have an issue on startup that the signal has not the state it should have.
The signals name is the SD_A_WP / GPIO01_IO07.
You see the behavior on the attached image - yellow line. What we did was a soft reboot with command "reboot" from linux.
So I guess as soon as linux resets, the signal reaches the pull up. Then it goes down to ~1V for about 300ms and goes back to pull up.
I already checked if the signal is used in UBoot but that seems not to be the case for the mx8MP. I also guess that there is no u-boot running in the first 300ms.
Is that behavior caused by nboot or by the chip itself? Is there a solution or should we switch over to another GPIO in the next hardware version?
GPIO in wrong state on startup
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Hello,
we are currently investigating the reset behavior. As far as I know, we do not use or configure this pin actively in NBoot,
The behavior might be the result of the combined behavior of PMIC and CPU.
Your F&S Support Team
