RTC initialization and status register
| ALRAWF | Alarm A write flag |
| ALRBWF | Alarm B write flag |
| WUTWF | Wakeup timer write flag |
| SHPF | Shift operation pending |
| INITS | Initialization status flag |
| RSF | Registers synchronization flag |
| INITF | Initialization flag |
| INIT | Initialization mode |
| ALRAF | Alarm A flag |
| ALRBF | Alarm B flag |
| WUTF | Wakeup timer flag |
| TSF | Time-stamp flag |
| TSOVF | Time-stamp overflow flag |
| TAMP1F | RTC_TAMP1 detection flag |
| TAMP2F | RTC_TAMP2 detection flag |