Is it possible to trigger a GPIO pin by an RTC alarm in VBAT mode only?

[Rookie38]

Hello ST Community,

In my application I want to pull up a Battery Latch Pin for a short time in VBAT mode using the integrated RTC Alarm Events.

Based on the datasheet of the STM32F722xx STM32F723xx it is described that:

When the microcontroller is supplied from VBAT, external interrupts and RTC alarm/events do not exit it from VBAT operation.

By pulling up a pin in VBAT state in case of an RTC alarm I want to "manually" exit the VBAT mode by activating the power supply via VDD.

According to my research on the RTC, there is no way to trigger an external interrupt to control or trigger a pin via RTC on VBAT only. Is my statement correct so far or is there a way to implement my intention?

Best regards

[waclawek.jan · Accepted solution]

?

JW

[Rookie38]

Thank you very much for the hint. I should have looked directly at the reference manual instead of the processor data sheet. As soon as I have read more about the functionalities of the RTC, I will start the implementation.