Nations Technologies Inc.
Tel
:
+86-755-86309900
:
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
19
/
631
protect
level
Boot mode
System Memory
Changing a Protection
Level
Perform user
Access to areas
JTAG/SWD
Main Flash
System Memory
SRAM
L0
level
Before 4KB of flash
main memory area
Read-write-
erase
Read-write-
erase
Read-write-erase
Read-write-
erase
Change to L1 or L2 is
allowed
After 4KB of flash
main memory area
Read-write-
erase
Read-write-
erase
Read-write-erase
Read-write-
erase
Flash main memory
area mass erase
Allow
Allow
Allow
Allow
Flash option byte area
Read-write-
erase
Read-write-
erase
Read-write-erase
Read-write-
erase
Flash system memory
area
Prohibit
Prohibit
Read-write-erase
Prohibit
SRAM (All)
Read and
write
Read and
write
Read and write
Read and
write
L1
level
Before 4KB of flash
main memory area
Prohibit
Read-only
Read-only
Read-only
L0 or L2 is allowed.
When changed to L0,
the main memory area
is automatically erased.
After 4KB of flash
main memory area
Prohibit
Read-write-
erase
Read-write-erase
Read-write-
erase
Flash main memory
area mass erase
Allow
Allow
Allow
Allow
Flash option byte area
Read-write-
erase
Read-write-
erase
Read-write-erase
Read-write-
erase
Flash system memory
area
Prohibit
Prohibit
Read-write-erase
Prohibit
SRAM (All)
Read and
write
Read and
write
Read and write
Read and
write