Flash option control register
| OPTLOCK | Option lock |
| OPTSTRT | Option start |
| BOR_LEV | BOR reset Level |
| WWDG_SW | User option bytes |
| IWDG_SW | User option bytes |
| nRST_STOP | User option bytes |
| nRST_STDBY | User option bytes |
| RDP | Read protect |
| nWRP | Not write protect |
| nDBOOT | Dual Boot mode (valid only when nDBANK=0) |
| nDBANK | Not dual bank mode |
| IWDG_STDBY | Independent watchdog counter freeze in standby mode |
| IWDG_STOP | Independent watchdog counter freeze in Stop mode |