SDAA473 November   2026 MSPM33C321A , MSPM33C321A-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Security Concept
    2. 1.2 Key Concepts
  5. 2TrustZone Architecture
    1. 2.1 MSPM33 Family Overview
    2. 2.2 TrustZone Feature
      1. 2.2.1 Security States – Secure, Non-secure, Non-secure Callable
      2. 2.2.2 First Security Attribute Define – SAU and IDAU
      3. 2.2.3 Second Security Attribute Define – Global Security Controller
      4. 2.2.4 Security Attribute with TrustZone® and GSC
      5. 2.2.5 Secure and Non-secure Debug Authentication
    3. 2.3 TrustZone® Software Development
  6. 3Develop TrustZone Based Application
    1. 3.1 Device Configuration
      1. 3.1.1 NONMAIN FLASH
        1. 3.1.1.1 Security and Privilege Configuration on FLASH
        2. 3.1.1.2 Other Configurations in NONMAIN FLASH
        3. 3.1.1.3 Configure NONMAIN FLASH in the Sysconfig
    2. 3.2 Develop Secure Application
      1. 3.2.1 Project Dependency
        1. 3.2.1.1 Structure of Secure Application Example
      2. 3.2.2 SAU and IDAU Configuration
        1. 3.2.2.1 Configure SAU in the Project
      3. 3.2.3 Global Security Controller Configuration
        1. 3.2.3.1 Configure GSC in the Sysconfig
        2. 3.2.3.2 Other Configurations in GSC
      4. 3.2.4 Defining Functions as Secure and Non-Secure
        1. 3.2.4.1 Define Non Secure Callable function in the Project
      5. 3.2.5 Code Implementation on Secure Application
        1. 3.2.5.1 Configure .cmd file to assign memory
        2. 3.2.5.2 Secure Application
        3. 3.2.5.3 Secure Interrupt and Non-secure Interrupt
        4. 3.2.5.4 Branch to Non-secure Application
    3. 3.3 Develop Non-Secure Application
      1. 3.3.1 Project Dependency
        1. 3.3.1.1 Structure of Non-secure Application Example
      2. 3.3.2 Code Implementation on Non-secure Application
        1. 3.3.2.1 Configure .cmd file to assign memory
        2. 3.3.2.2 Non-secure Application and NSC Function Call
  7. 4Evaluate TrustZone Based Application
    1. 4.1 Environment Setup
    2. 4.2 Load Secure and Non-secure Images Together
      1. 4.2.1 Step 1: Build the Non-Secure Application
      2. 4.2.2 Step 2: Programming the full.txt File
    3. 4.3 Load Secure and Non-secure Images separately
      1. 4.3.1 Step 1: Build the Non-Secure Application
      2. 4.3.2 Step 2: Programming the Non-Secure Application
      3. 4.3.3 Step 3: Build the Secure Application
      4. 4.3.4 Step 4: Programming the Secure Application
    4. 4.4 Debug and Evaluate the Example
      1. 4.4.1 Add Symbols in the Debug
      2. 4.4.2 Observe Results with Free Run
      3. 4.4.3 Add Breakpoints to Observe the Process
  8. 5FAQ
    1. 5.1 How to Modify the Range of S/NS SRAM
    2. 5.2 How to Modify the Range of S/NS FLASH
    3. 5.3 How to Modify the Security Attribute on Peripherals
  9. 6Summary
  10. 7References

3.2.2 SAU and IDAU Configuration

In MSPM33, IDAU is pre-defined by TI. See pre-definition in the Table 2-2. SAU can be configured by the user to define S/NS/NSC based on how the SAU_CTRL and SAU_RLAR are configured.

Table 3-2 SAU Control on the S, NS and NSC Properties
SAU_CTRL.ENABLE SAU_CTRL.ALL_NS SAU_RLAR.ENABLE SAU_RLAR.NSC SAU Security Attribute
0 0 - - All of the memory is marked Secure (Reset state)
0 1 - - All of the memory is marked NS
1 - 0 - All of the region as per SAU_RBAR and SAU_RLAR is marked Secure
1 - 1 1 All of the region as per SAU_RBAR and SAU_RLAR is NSC
1 - 1 0 All of the region as per SAU_RBAR and SAU_RLAR is NS
Note: When users need to configure security attribution unit (SAU) for security attribution, configured address is based on logical address. In bank-swappable configuration, please carefully configure SAU based on logical address.

Users can configure SAU to configure the final security attribute of a different address. Any violation of the security property results in a SecureFault interrupt. When the device powers on and SAU is not configured, all memory is Secure by default. See Table 2-2 for the security attributes through SAU+IDAU.

Note: At reset before any SAU region is programmed, SAU_CTRL.ALLNS register bit selects the default internal security level. On reset, SAU_CTRL.ALLNS is always set to zero, setting all memory to Secure state. Setting SAU_CTRL.ALLNS prevents any external IDAU from overriding security level.