Option Byte Description:
Flash OPTR - 0x1FFF 7800
   Bits     Name                Settings
   7-0      Read Protection     0xAA = Level 0 - no protection
                                0xXX = (except 0xAA and 0xCC): Level 1 - memory read protection - protects Flash program memory
                                0xCC = Level 2 - Disable debug and chip read protection
    8       BOR_EN              0: Configurable brown out reset disabled, 1: Configurable brown out reset enabled
  10-9      BORR_LEV            0xxx: BOR threshold at rising VDD supply
                                00: BOR rising level 1 with threshold around 2.1 V
                                01: BOR rising level 2 with threshold around 2.3 V
                                10: BOR rising level 3 with threshold around 2.6 V
                                11: BOR rising level 4 with threshold around 2.9 V
  12-11     BORF_LEV            0xxx: BOR threshold at falling VDD supply
                                00: BOR falling level 1 with threshold around 2.0 V
                                01: BOR falling level 2 with threshold around 2.2 V
                                10: BOR falling level 3 with threshold around 2.5 V
                                11: BOR falling level 4 with threshold around 2.8 V
    13      NRST_STOP           0: Reset generated when entering Stop mode, 1: No reset generated
    14      NRST_STDBY          0: Reset generated when entering Standby mode, 1: No reset generated
    15      nRST_SHDW           0: Reset generated when entering Shutdown mode, 1: No reset generated
    16      IWDG_SW             0: Hardware independent watchdog, 1: Software independent watchdog
    17      IWDG_STOP           0: Independent watchdog counter is frozen in Stop mode, 1: counter is running
    18      IWDG_STDBY          0: Independent watchdog counter is frozen in Stop mode, 1: counter is running
    
    19      WWDG_SW             0: Hardware window watchdog, 1: Software window watchdog
    20      Reserved            0 (Default)
    21      HSE_NOT_REMAPPED    0: Enable 1:Disable
    22      RAM_PARITY_CHECK    0: Enable 1:Disable
    23      SECURE_MUXING_EN    0: Disable 1:Enable
    24      NBOOT_SEL           0: BOOT0 pin 1:NBOOT0 option bit
    25      NBOOT1
    26      NBOOT0              0: NBOOT0 = 0 1:NBOOT0=1
  28-27     NRST_MODE[1:0]      PF2-NRST pin configuration
                                00: reserved
                                01: Reset input only
                                10: PF2 GPIO
                                11: Bidirectional reset
    29      IRHEN               0: Internal resets are propagated as simple pulse on NRST pin 1:Internal resets drives NRST pin low until it is seen as low level
  31-30     FDCAN_BL_CK[1:0]    FDCAN bootloader clock source
                                00: HSI48
                                01: HSE crystal - 12MHz
                                10: HSE crystal - 24MHz
                                11: HSE crystal - 48MHz

FLASH PCROP1ASR Register     - 0x1FFF 7808
   Bits     Name                Settings
   8-0     PCROP1A_START[8:0]   PCROP1A area start offset

FLASH PCROP1AER Register     - 0x1FFF 7810
Bits Name                Settings
   8-0     PCROP1A_END[8:0]     PCROP1A area end offset
    31     PCROP_RDP            0: Not erased 1: Erased

Write protection option bytes - 0x1FFF 7818
    - Bits 6:0   WRP1A_STRT[6:0]: WRP area A start offset
    - Bits 22:16 WRP1A_END[6:0]: WRP area A end offset

Write protection option bytes - 0x1FFF 7820
    - Bits 6:0   WRP1B_STRT[6:0]: WRP area B start offset 
    - Bits 31:16 WRP1B_END[6:0]: WRP area B end offset

FLASH PCROP1BSR Register     - 0x1FFF 7828
Bits Name                Settings
   8-0     PCROP1B_START[8:0]   PCROP1B area start offset

FLASH PCROP1BER Register     - 0x1FFF 7830
Bits Name                Settings
   8-0     PCROP1B_END[8:0]     PCROP1B area end offset

FLASH SECR Register          - 0x1FFF 7870
Bits Name                Settings
   6-0     SEC_SIZE[6:0]:       Securable memory area size
    16     BOOT_LOCK            0: Boot based on the pad/option bit configuration 1: Boot forced from main flash memory

Optional:MCU REV_ID can be check as well. Enable the check and enter the expected Revision.

The Flash Blank State is 0xFF.