DocID018909 Rev 11 805/1731
RM0090 Real-time clock (RTC)
828
26.5 RTC interrupts
All RTC interrupts are connected to the EXTI controller.
To enable the RTC Alarm interrupt, the following sequence is required:
1. Configure and enable the EXTI Line 17 in interrupt mode and select the rising edge
sensitivity.
2. Configure and enable the RTC_Alarm IRQ channel in the NVIC.
3. Configure the RTC to generate RTC alarms (Alarm A or Alarm B).
To enable the RTC Wakeup interrupt, the following sequence is required:
1. Configure and enable the EXTI Line 22 in interrupt mode and select the rising edge
sensitivity.
2. Configure and enable the RTC_WKUP IRQ channel in the NVIC.
3. Configure the RTC to generate the RTC wakeup timer event.
To enable the RTC Tamper interrupt, the following sequence is required:
1. Configure and enable the EXTI Line 21 in interrupt mode and select the rising edge
sensitivity.
2. Configure and Enable the TAMP_STAMP IRQ channel in the NVIC.
3. Configure the RTC to detect the RTC tamper event.
To enable the RTC TimeStamp interrupt, the following sequence is required:
1. Configure and enable the EXTI Line 21 in interrupt mode and select the rising edge
sensitivity.
2. Configure and Enable the TAMP_STAMP IRQ channel in the NVIC.
3. Configure the RTC to detect the RTC timestamp event.
Table 119. Interrupt control bits
Interrupt event Event flag
Enable
control
bit
Exit the
Sleep
mode
Exit the
Stop
mode
Exit the
Standby
mode
Alarm A ALRAF ALRAIE yes yes
(1)
1. Wakeup from STOP and Standby modes is possible only when the RTC clock source is LSE or LSI.
yes
(1)
Alarm B ALRBF ALRBIE yes yes
(1)
yes
(1)
Wakeup WUTF WUTIE yes yes
(1)
yes
(1)
TimeStamp TSF TSIE yes yes
(1)
yes
(1)
Tamper1 detection TAMP1F TAMPIE yes yes
(1)
yes
(1)
Tamper2 detection
(2)
2. If RTC_TAMPER2 pin is present. Refer to device datasheet pinout.
TAMP2F TAMPIE yes yes
(1)
yes
(1)
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