Flash Proprietary Code Readout Protection (Pcrop); Table 19. Access Status Versus Protection Level And Execution Modes; Figure 3. Changing Read Protection (Rdp) Level - ST STM32G0 1 Series Reference Manual

Embedded Flash memory (FLASH)

Table 19. Access status versus protection level and execution modes

Protection
Area
level
1
Main Flash
memory
2
1
System
(2)
memory
2
1
Option bytes
2
1
Backup
registers
2
1
OTP
2
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 Main memory is erased when the RDP option byte is programmed with all level of protections disabled (0xAA).
4. The backup registers are erased when RDP changes from Level 1 to Level 0.
3.5.2

FLASH proprietary code readout protection (PCROP)

Two areas of the Flash memory (Flash memory bank for dual-bank devices) can be
protected against unwanted read and/or write by a third party.
94/1390

Figure 3. Changing read protection (RDP) level

RDP = 0xCC
Level 2
RDP = 0xCC
Read-protection level increase
Read-protection level decrease (with full or partial mass erase)
Erase/program option bytes without changing read-protection level (RDP kept unchanged)
User execution (BootFromFlash)
Read Write
Yes Yes
Yes Yes
Yes No
Yes No
(3)
Yes Yes
Yes No
Yes Yes
Yes Yes
Yes Yes
Yes Yes
RM0444 Rev 5
Level 1
RDP ≠ 0xAA ≠ 0xCC
RDP ≠ 0xCC ≠ 0xAA
RDP = 0xCC
Erase
Yes
Yes
No
No
Yes
No
N/A
N/A
N/A
N/A
RM0444
RDP = 0xAA
Level 0
RDP = 0xAA
MSv33468V3
Debug/ BootFromRam/
BootFromLoader
Read Write Erase
No No
(1) (1)
N/A N/A
Yes No
(1) (1)
N/A N/A
(3)
Yes Yes
(1) (1)
N/A N/A
No No
(1) (1)
N/A N/A
No No
(1) (1)
N/A N/A
(3)
No
(1)
N/A
No
(1)
N/A
Yes
(1)
N/A
(4)
No
(1)
N/A
N/A
(1)
N/A