GD32W51x User Manual
62
cleared at the end of the SRAM1 erase operation
Note
:
This bit is w rite-protected: setting this bit is possible only after the correct key
sequence is w ritten in the SYSCFG_SKEY register.
SYSCFG SRAM1 key register (SYSCFG_SKEY)
Address offset:
0x5C
Reset value: 0x0000 0000
When the system is secure (TZEN =1), this register can be protected against non-secure
access by setting the SRAM1SE bit in the SYSCFG_SECFG register. When SRAM1SE bit is
set, only secure access is allowed. A non-secure read/write access is RAZ/WI and generates
an illegal access event.
When the system is not secure (TZEN=0), there is no access restriction.
This register can be read and written by privileged and unprivileged access.
This register has to be accessed by word(32-bit)
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Reserved
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Reserved
KEY[7:0]
W
Bits
Fields
Descriptions
31:8
Reserved
Must be kept at reset value.
7:0
KEY[7:0]
SRAM1 w rite protection key for softw are erase.
The follow ing steps are required to unlock the w rite protection of the SRAM1ER S
bit in the SYSCFG_SCS register.
1.
Write “0xCA” into Key[7:0]
2.
Write “0x53” into Key[7:0]
Note
: Writing a w rong key reactivates the w rite protection.
SYSCFG SRAM1 write protection register 0 (SYSCFG_SWP0)
Address offset:
0x60
Reset value: 0x0000 0000
When the system is secure (TZEN =1), this register can be protected against non-secure
access by setting the SRAM1SE bit in the SYSCFG_SECFG register. When SRAM1SE bit is
set, only secure access is allowed. A non-secure read/write access is RAZ/WI and generates
an illegal access event.
When the system is not secure (TZEN=0), there is no access restriction.