SLUUDG7A December 2025 – November 2026 MSPM33C321A , MSPM33C321A-Q1
The Cortex®-M33 TrustZone® security allows the programmer to partition memory into three different types of regions: secure, non-secure, and non-secure callable. Processor in secure state can access both non-secure and secure resources, while processor in non-secure state can only access non-secure resources. Non-secure callable regions of memory serves as a secure gateway (bridge) between the non-secure region and the secure region, allows the programmer to jump to a secure region of memory when the user calls a SG instruction. For a more detailed description please see the Enable Trustzone for Secure Application in MSPM33 MCUs or TrustZone® technology for Armv8-M Architecture documentation.
To define which regions of memory are secure and non-secure the Security Attribution unit (SAU) and Implementation Defined Attribution Unit (IDAU) are used. The IDAU is set at the RTL level and is configured by TI. For information on how the IDAU is configured please see the CPU section of the MSPM33C3-Series 160MHz Microcontrollers Technical Reference Manual.
The SAU is used by the CPU subsystem (CPUSS) to define regions of memory as secure and non-secure. This peripheral allows the programmer to partition the code as secure and non-secure. For information on how the SAU and IDAU work together to define regions as secure or non-secure please see TrustZone® technology for Armv8-M Architecture documentation.
Enable Trustzone for Secure Application in MSPM33 MCUs gives a guide on how to configure TrustZone® during code development, and how to evaluate TrustZone® example in MSPM33 SDK.