This application note describes the features of the real-time clock (RTC) controller embedded in Ultra Low Power Medium-density, Ultra Low Power High-density, F0, F2 and F4 series devices microcontrollers, and the steps required to configure the RTC for use with the calendar, alarm, periodic wakeup unit, tamper detection, timestamp and calibration applications. Examples are provided with configuration information to enable you to quickly and correctly configure the RTC for calendar, alarm, periodic wakeup unit, tamper detection, time stamp and calibration applications.