
DocID024597 Rev 5
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RM0351
Embedded Flash memory (FLASH)
136
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
Section 3.4.2: Option bytes programming
).
A double word is split up as follows in the option bytes:
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
or from the Option byte registers:
•
Flash option register (FLASH_OPTR)
•
Flash Bank 1 PCROP Start address register (FLASH_PCROP1SR)
•
Flash Bank 1 PCROP End address register (FLASH_PCROP1ER)
•
Flash Bank 1 WRP area A address register (FLASH_WRP1AR)
•
Flash Bank 1 WRP area B address register (FLASH_WRP1BR)
•
Flash Bank 2 PCROP Start address register (FLASH_PCROP2SR)
•
Flash Bank 2 PCROP End address register (FLASH_PCROP2ER)
•
Flash Bank 2 WRP area A address register (FLASH_WRP2AR)
•
Flash Bank 2 WRP area B address register (FLASH_WRP2BR)
.
Table 12. Option byte format
63-24
23-16
15 -8
7-0
31-24
23-16
15 -8
7-0
Complemented
option byte 3
Complemented
option byte 2
Complemented
option byte 1
Complemented
option byte 0
Option
byte 3
Option
byte 2
Option
byte 1
Option
byte 0
Table 13. Option byte organization
BANK
Address
63
[62:56]
[55:48]
[47:40]
[39:32]
31
[30:24]
[23:16]
[15:8]
[7:0]
Bank 1
1FFF7800
USER OPT
RDP
USER OPT
RDP
1FFF7808
Unused
PCROP1_STRT
Unused
PCROP1_STRT
1FFF7810
PCROP_RDP
Unused
PCROP1_END
PCROP_RDP
Unused
PCROP1_END
1FFF7818
Unused
WRP1A
_END
Unused
WRP1A
_STRT
Unused
WRP1A
_
END
Unused
WRP1A
_STRT
1FFF7820
Unused
WRP1B
_END
Unused
WRP1B
_STRT
Unused
WRP1B
_
END
Unused
WRP1B
_STRT