Table 2-5 Read Protection Configuration List - Nations N32G430 Series User Manual

Read protection status
L1 level
Unprotected
L2 level
L1 level

L0 level:
 In unprotected state, corresponding (RDP1 == 0xA5 & nRDP1 == 0x5A) && (RDP2!= 0xCC | nRDP2!=
0x33);
 The main memory area and option byte block can be read arbitrarily;
 The write protection property of each page can be configured for programming and erasing;

L1 level:
 The corresponding ~ ((RDP1 == 0xA5 & nRDP1 == 0x5A) && (RDP2!= 0xCC | nRDP2!= 0x33)) | (RDP2
== 0xCC & nRDP2 == 0x33));
 Only the read operation of the main storage area from the user code is allowed, that is, when the program
is started from the main flash memory in non debugging mode, the read operation of the main storage area
is allowed;
 All pages can be programmed by the code executed in the main flash memory (realizing IAP or data storage
and other functions);
 All pages are not allowed to write or erase in debug mode or after booting from internal SRAM (except for
mass erase);
 All functions of loading code into the built-in SRAM through JTAG/SWD and then execute it are still valid,
or they can be started from the built-in SRAM through JTAG/SWD, which can be used to remove read
protection;
 When the read-protected option byte is rewritten to the unprotected L0 level, all the main storage areas will
be automatically erased, and the process is as follows: (Erasing the option byte block will not result in
automatic whole erasing operation, because the result of erasing is 0xFF, which is equivalent to still being
in the protection state of L1 level)

Write the correct key value sequence to unlock the option byte area in FLASH_OPTKEY;

The bus initiates a command to erase the entire option byte area (Page erase);

Bus write 0xA5 to read protection option byte;

Automatically erase all main storage areas internally;

Automatically write 0xA5 to read protection option byte internally;

When the system is reset (such as software reset, etc.), the option byte block (including the new
RDP value 0xA5) will be reloaded into the system, and the read protection will be released;
 The following access operations to the flash memory will be prohibited:

Table 2-5 Read protection configuration list

RDP1
0xFF
0xA5
0xXX
Not the above three configurations
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nRDP1 nRDP2
0xFF RDP2! = 0xCC || nRDP2! = 0x33
0x5A RDP2! = 0xCC || nRDP2! = 0x33
0xXX 0x33
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RDP2
0xCC