RTC status clear register
| CALRAF | Clear alarm A flag Writing 1 in this bit clears the ALRAF bit in the RTC_SR register. |
| CTSF | Clear timestamp flag Writing 1 in this bit clears the TSOVF bit in the RTC_SR register. |
| CTSOVF | Clear timestamp overflow flag Writing 1 in this bit clears the TSOVF bit in the RTC_SR register. It is recommended to check and then clear TSOVF only after clearing the TSF bit. Otherwise, an overflow might not be noticed if a timestamp event occurs immediately before the TSF bit is cleared. |