ST STM32L4+ Series Reference Manual page 133

RM0432
3.4 FLASH option bytes
3.4.1 Option bytes description
The option bytes are configured by the end user depending on the application requirements.
As a configuration example, the watchdog may be selected in hardware or software mode
(refer to
A double word is split up as follows in the option bytes:
63-24 23-16
Complemented Complemented
option byte 3 option byte 2
The organization of these bytes inside the information block is as shown in
The option bytes can be read from the memory locations listed in
Option byte registers:
•
Flash option register (FLASH_OPTR)
•
Flash PCROP1 Start address register (FLASH_PCROP1SR)
•
Flash PCROP1 End address register (FLASH_PCROP1ER)
•
Flash WRP1 area A address register (FLASH_WRP1AR)
•
Flash WRP1 area B address register (FLASH_WRP1BR)
•
Flash PCROP2 Start address register (FLASH_PCROP2SR)
•
Flash PCROP2 End address register (FLASH_PCROP2ER)
•
Flash WRP2 area A address register (FLASH_WRP2AR)
•
Flash WRP2 area B address register
BANK Address
1FF00000
1FF00008
1FF00010
Bank 1
1FF00018
1FF00020
Section 3.4.2: Option bytes
Table 13. Option byte format
15 -8
Complemented
option byte 1
Table 14. Option byte organization
[63:56] [55:48]
USER OPT
Unused and
PCROP1_STRT[16]
PCROP_RDP and
Unused and
PCROP1_END[16]
WRP1A
Unused
_END
WRP2A
Unused
_END
programming).
7-0 31-24
Complemented Option
option byte 0 byte 3
(FLASH_WRP2BR).
[47:40] [39:32]
RDP
PCROP1_STRT[15:0]
PCROP1_END[15:0]
WRP1A
Unused
_STRT
WRP2A
Unused
_STRT
RM0432 Rev 6
Embedded Flash memory (FLASH)
23-16 15 -8
Option Option
byte 2 byte 1
Table 14
[31:24] [23:16]
USER OPT
Unused and
PCROP1_STRT[15]
PCROP1_STRT[16]
PCROP_RDP and
Unused and PCROP1_END[15:0]
PCROP1_END[16]
WRP1A_
Unused Unused
END
WRP2A_
Unused Unused
END
7-0
Option
byte 0
Table 14.
or from the
[15:8] [7:0]
RDP
WRP1A
_STRT
WRP2A
_STRT
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