GD32W51x User Manual
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secure callable (NSC), the IDAU memory map partition is not configurable and fixed by
hardware implementation (refer to
Table 1-5. Memory map based on IDAU mapping of
). However the SAU can change security attribution of the memory by
software. The security attribution of a memory address is determined by IDAU and SAU
together.
If the definitions are different, the attribution with a higher security level will be used
(S > NSC > NS).
Figure 1-3. Example of memory map security attribution vs SAU
shows an example of typical eight SAU regions mapping based on
IDAU regions. The user can split and choose the secure, non-secure or NSC regions for
external memories as needed.
Based on IDAU security attribution, the Flash, system SRAM0~3 and peripherals memory
space is aliased twice for secure and non-secure state. However, the external memories
(QSPI_FLASH and SQPI_PSRAM) space is not aliased.
Figure 1-3. Example of memory map security attribution vs SAU configuration
regions
NS
0x0000 0000
NS
0x0800 0000
NSC
0x0C00 0000
NS
0x1000 0000
NS
0x2000 0000
NSC
0x3000 0000
NS
0x4000 0000
NSC
0x5000 0000
NS
0x6000 0000
0xDFFF FFFF
Code - external
memories
Code - Flash and
SRAM
Code - external
memories
SRAM
Peripherals
External
memories
IDAU security
attribution
S or NS or NSC
NS
S or NSC
NS
S or NSC
NS
S or NSC
S or NS or NSC
SAU security
attribution
S or NS or NSC
NS
S or NSC
NS
S or NSC
NS
S or NSC
S or NS or NSC
Final security
attribution
When the TrustZone security is activated by the TZEN option bit in the EFUSE_TZCTL
register or the TZEN option bit in option byte, the default system security refer to
Table 1-2. Default system security state
security state
CPU
Cortex-M33 is in secure state after reset. The boot address must be in
secure address.
Memory map
SAU is fully secure after reset. Consequently, all memory map is fully
secure. Up to 8 SAU configurable regions are available for security
attribution.
Flash
Flash is secure after reset.