HAL RTC How to Use

group RTC_How_To_Use

The Real-Time Clock (RTC) is an independent BCD/Binary timer/counter.

The RTC provides:

  • Time-of-day clock/calendar

  • Programmable alarms

  • Timestamp feature

  • Automatic wake-up timer

The RTC clock, named RTCCLK, can come from different sources:

  • HSE

  • LSE

  • LSI

By default, the RTC prescalers are configured to work with the LSE clock at 32.768 kHz.

RTC and microcontroller low power modes

The MCU can be woken up from low power mode by RTC functions.

The RTC functions are:

  • Alarm A event.

  • Alarm B event.

  • Timestamp event.

  • Wake-up timer event.