STMicroelectronics STM32WL5 Series

RM0453 Rev 5 121/1450
RM0453 Embedded flash memory (FLASH)
154
Figure 8. Changing the RDP level
MSv62613V1
Options write (RDP level increase) includes:
- Options page erase
- New options program
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Write options including
RDP = 0xAA
Write options including
RDP = 0xCC
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Level 1
5'30xAA
5'30xCC
default
Level 2
RDP = 0xCC
Level 0
RDP = 0xAA
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Other;ƐͿŽƉƚŝŽŶ;ƐͿŵŽĚŝĨŝĞĚ
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RDP сϬdž
Options write (RDP level decrease) includes:
- Full mass erase or partial mass erase to not erase secure and or PCROP pages
- Backup registers and SRAM2 erase
- Options page erase
- New options program
Options write (RDP level identical) includes:
- Options page erase
- New options program
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Write options including
RDP = 0xAA
Secure CPU2 options write (RDP level identical) includes:
- Options page erase
- New options program
Secure CPU2 options write (RDP level decrease) includes:
- Options page erase
- New options program
Table 20. Access status versus protection level and execution modes
Area
Protection
level
User execution (BootFromFlash)
Debug/ BootFromRam/
BootFromLoader/|BootFromSFI
/RSS
Read Write Erase Read Write Erase
Main flash
memory
1 Yes Yes Yes No No No
(4)
2 Yes Yes Yes N/A
(1)
N/A
(1)
N/A
(1)
System
memory
(2)
1Yes No No YesNoNo
2 Yes No No N/A
(1)
N/A
(1)
N/A
(1)
Option bytes
1Yes Yes
(3)
Yes Ye s Yes
(3)
Yes
2Yes
CPU1 and CPU2
none secure - No
CPU1 and CPU2
none secure - No
N/A
(1)
N/A
(1)
N/A
(1)
CPU2 secure - Yes CPU2 secure - Yes
Backup
registers
1 Yes Yes N/A No No No
(4)
2Yes Yes N/A N/A
(1)
N/A
(1)
N/A
(1)
SRAM2
1 Yes Yes N/A No No No
(5)
2Yes Yes N/A N/A
(1)
N/A
(1)
N/A
(1)
1. When the protection level 2 is active, the debug port, the boot from RAM and the boot from system memory are disabled.
2. The system memory is only read-accessible, whatever the protection level (0, 1 or 2) and execution mode.
3. The flash non secure main memory is erased when the RDP option byte is programmed from level 1 to level 0. The flash
secure main memory is also erased when the ESE option byte is regressed at the same time as the RDP option byte
programming from level 1 to level 0.
4. The backup registers are erased when RDP changes from level 1 to level 0.