DocID018909 Rev 11
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RM0090
Embedded Flash memory interface
112
0x1FFE C000
Reserved
Reserved
0x1FFE C008
Reserved
SPRMOD and Write protection
nWRP bits for
sectors 12 to 23
Table 15. Description of the option bytes (STM32F405xx/07xx and
STM32F415xx/17xx)
Option bytes (word, address 0x1FFF C000)
RDP:
Read protection option byte.
The read protection is used to protect the software code stored in Flash memory.
Bits 15:8
0xAA: Level 0, no protection
0xCC: Level 2, chip protection (debug and boot from RAM features disabled)
Others: Level 1, read protection of memories (debug features limited)
USER:
User option byte
This byte is used to configure the following features:
– Select the watchdog event: Hardware or software
– Reset event when entering the Stop mode
– Reset event when entering the Standby mode
Bit 7
nRST_STDBY
0: Reset generated when entering the Standby mode
1: No reset generated
Bit 6
nRST_STOP
0: Reset generated when entering the Stop mode
1: No reset generated
Bit 5
WDG_SW
0: Hardware independent watchdog
1: Software independent watchdog
Bit 4
0x1: Not used
Bits 3:2
BOR_LEV:
BOR reset Level
These bits contain the supply level threshold that activates/releases the reset.
They can be written to program a new BOR level value into Flash memory.
00: BOR Level 3 (VBOR3), brownout threshold level 3
01: BOR Level 2 (VBOR2), brownout threshold level 2
10: BOR Level 1 (VBOR1), brownout threshold level 1
11: BOR off, POR/PDR reset threshold level is applied
Note: For full details on BOR characteristics, refer to the “Electrical characteristics”
section of the product datasheet.
Bits 1:0
0x1: Not used
Table 14. Option byte organization (continued)
Address
[63:16]
[15:0]