I am making a custom board based on the evaluation board, and this is a question regarding whether it is likely to cause problems if I make a 5V net which is switchable to power down the USB 5V just before the the IMX8QXP is made to go into the “mem” state and then power them back up again upon “wake”
Now using the processor sleep state command
echo mem > /sys/power/state
The processor goes into a deep sleep mode but the 3.3V and 5V nets are still up. This is fine, as I have rigged up a SPST NO switch from 3.3V to pin 45 to wake it again. It works perfect.
Now the thing is I want the USB’s to go off and they are still live with the processor asleep.
So I can make the 5V net switchable, and write a bit of code to turn off, no problem.
Having ruthlessly used the evaluation board USB implementation in my design, taking the USB2514B-AEZC-CT-ND hub controller as it is. Can the module be programmed to send out a RESET so I can send a reset to the USB hub and register all the devices on the hub? Or will just powering up the hub via my new switchable 5V net be enough ?
I just cant prototype this bit on the evaluation board easiliy.