I am using STM32F4 discovery board RTC Alarms (A and B) through EXTI line interrupt . What does it means ?? 1. Can i attach Usart Rx pin to EXTI line interrupt 2. want to achieve standby rtc mode using rtc alam for 15min and for 1min

[S.Ma]

Exti on alternate function is possible if you directly write the exti registers because HAL defines are missing.

[waclawek.jan]

> RTC Alarms (A and B) through EXTI line interrupt . What does it means ??

In other words, you enable one of the alarms to interrupt in RTC, then you have to enable the respective line 17 in EXTI, and then enable RTC_Alarm_IRQn in NVIC - and RTC_Alarm_IRQ is in fact the EXTI17 interrupt.

JW