STMicroelectronics STM32F05 series Reference Manual page 61

RM0091
Table 11.
Flash memory
address
0x1FFF F808
On every system reset, the option byte loader (OBL) reads the information block and stores
the data into the Option byte register (FLASH_OBR) and the Write protection register
(FLASH_WRPR). Each option byte also has its complement in the information block. During
option loading, by verifying the option bit and its complement, it is possible to check that the
loading has correctly taken place. If this is not the case, an option byte error (OPTERR) is
generated. When a comparison error occurs the corresponding option byte is forced to
0xFF. The comparator is disabled when the option byte and its complement are both equal
to 0xFF (Electrical Erase state).
Description of the option bytes (continued)
WRPx: Flash memory write protection option bytes
Bits [31:24]: nWRP1
Bits [23:16]: WRP1 (stored in FLASH_WRPR[15:8])
Bits [15:8]: nWRP0
Bits [7:0]: WRP0 (stored in FLASH_WRPR[7:0])
0: Write protection enabled
1: Write protection disabled
Refer to Section 3.3.2: Write protection
Doc ID 018940 Rev 1
Option byte description
Option bytes
for more details.
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