Flash option register
| RDP | Read protection level |
| BOR_LEV | BOR reset Level |
| nRST_STOP | nRST_STOP |
| nRST_STDBY | nRST_STDBY |
| IDWG_SW | Independent watchdog selection |
| IWDG_STOP | Independent watchdog counter freeze in Stop mode |
| IWDG_STDBY | Independent watchdog counter freeze in Standby mode |
| WWDG_SW | Window watchdog selection |
| BFB2 | Dual-bank boot |
| DUALBANK | Dual-Bank on 512 KB or 256 KB Flash memory devices |
| nBOOT1 | Boot configuration |
| SRAM2_PE | SRAM2 parity check enable |
| SRAM2_RST | SRAM2 Erase when system reset |