Calendar initialization and configu

Calendar initialization and configurationTo program the initial time and date calendar values, including the time format and theprescaler configuration, the following sequence is required:1. Set INIT bit to 1 in the RTC_ISR register to enter initialization mode. In this mode, thecalendar counter is stopped and its value can be updated.2. Poll INITF bit of in the RTC_ISR register. The initialization phase mode is entered whenINITF is set to 1. It takes around 2 RTCCLK clock cycles (due to clock synchronization).3. To generate a 1 Hz clock for the calendar counter, program both the prescaler factors inRTC_PRER register.4. Load the initial time and date values in the shadow registers (RTC_TR and RTC_DR),and configure the time format (12 or 24 hours) through the FMT bit in the RTC_CRregister.5. Exit the initialization mode by clearing the INIT bit. The actual calendar counter value isthen automatically loaded and the counting restarts after 4 RTCCLK clock cycles.