Control/status register
| LSION | LSI oscillator enable |
| LSIRDY | LSI oscillator ready |
| RMVF | Remove reset flags |
| OBLRSTF | Option byte loader reset flag |
| PINRSTF | Pin reset flag |
| PWRRSTF | BOR or POR/PDR flag |
| SFTRSTF | Software reset flag |
| IWDGRSTF | Independent window watchdog reset flag |
| WWDGRSTF | Window watchdog reset flag |
| LPWRRSTF | Low-power reset flag |