15.4.7.2 Wake-Up by RTC and RTT Alarm

The RTC and the RTT can be programmed to perform a wake-up of the device from Backup mode. This can be enabled by writing SUPC_BMR.RTCWKEN=1 and/or SUPC_BMR.RTTWKEN=1.

When the RTC is enabled to perform a system wake-up, the triggering event can be either the alarm event configured by writing RTC alarm registers (RTC_TIMALR, RTC_CALALR) or an abnormal behavior of the RTC reported by the on-the-fly RTC integrity circuitry. To determine which source triggered the RTC wake-up, refer to the RTC_SR in the section “Real-Time Controller (RTC)”.

Refer to the sections “Real-Time Controller (RTC)” or “Real-Time Timer (RTT)” to configure the alarms (condition of wake-up).

The SUPC does not provide any status as the information is available in the user interface of either the RTT or the RTC.