stm32u5g9,zephyr, low power manager

[devin-hu]

Hi,

I'm using the Zephyr platform with the STM32U5G9ZJ-DK2 board. I want to put the device into a low-power mode when it's not working. After modifying the DTS file and enabling power management, the device can enter and wake up from Stop3 mode normally. However, according to the datasheet, all IOs are in a floating state in Stop3 mode, but I need to control peripheral devices through some IOs. Is there any way for me to handle these IOs when entering and exiting Stop3, or can I choose to enter only Stop2 mode?

Yang,

BR

[Sarra.S]

Hello @devin-hu, 

You can handle IOs in Stop3 mode by configuring pull-up or pull-down resistors before entering the mode, using the APC bit in the PWR_APCR register, or you can also configure them in analog mode to reduce power consumption. 

Also, note that, after wakeup from Stop3 mode, the pull configuration remains as long as the APC bit is set