Flash option register
| RDP | Read protection level |
| BOREN | BOR reset Level |
| BORF_LEV | These bits contain the VDD supply level threshold that activates the reset |
| BORR_LEV | These bits contain the VDD supply level threshold that releases the reset. |
| nRST_STOP | nRST_STOP |
| nRST_STDBY | nRST_STDBY |
| nRSTS_HDW | nRSTS_HDW |
| 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 |
| RAM_PARITY_CHECK | SRAM parity check control |
| nBOOT_SEL | nBOOT_SEL |
| nBOOT1 | Boot configuration |
| nBOOT0 | nBOOT0 option bit |
| NRST_MODE | NRST_MODE |
| IRHEN | Internal reset holder enable bit |