SLUUDG7A December   2025  – November 2026 MSPM33C321A , MSPM33C321A-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Overview of Security Functionality
    1. 1.1 Terminology
    2. 1.2 Platform Security Enablers
  5. 2Device Security Model
    1. 2.1 Device Identity
    2. 2.2 Initial Conditions at Boot
    3. 2.3 Boot Configuration Routine (BCR)
    4. 2.4 Bootstrap Loader (BSL)
    5. 2.5 Lifecycle Management
      1. 2.5.1 Lifecycle Transitions
    6. 2.6 Boot Service
    7. 2.7 Boot Flow
    8. 2.8 User-Specified Security Policies
      1. 2.8.1 Boot Configuration Routine (BCR) Policies
        1. 2.8.1.1 Serial Wire Debug Related Policies
          1. 2.8.1.1.1 No Restrictions Scenario
          2. 2.8.1.1.2 Custom Restrictions Scenario
          3. 2.8.1.1.3 Fully Restricted Scenario
        2. 2.8.1.2 Bootstrap Loader (BSL) Enable/Disable Policy
        3. 2.8.1.3 Flash Memory Protection and Integrity Related Policies
          1. 2.8.1.3.1 Locking the Application (MAIN) Flash Memory
          2. 2.8.1.3.2 Locking the Configuration (NONMAIN) Flash Memory
          3. 2.8.1.3.3 Security and Privilege Protection on Application (MAIN, DATA) Flash Memory
          4. 2.8.1.3.4 Verifying Integrity of Application (MAIN) Flash Memory
      2. 2.8.2 Bootstrap Loader (BSL) Security Policies
        1. 2.8.2.1 BSL Access Password
        2. 2.8.2.2 BSL Read-out Policy
        3. 2.8.2.3 BSL Security Alert Policy
      3. 2.8.3 Customer Secure Code (CSC) Security Policies
        1. 2.8.3.1 CSC Enforced Bankswap
        2. 2.8.3.2 CSC Key Write to KEYSTORE
      4. 2.8.4 Configuration Data Error Resistance
        1. 2.8.4.1 CRC-Backed Configuration Data
          1. 2.8.4.1.1 BCR Configuration CRC Fail Handling
          2. 2.8.4.1.2 TI Factory Trim Data CRC Fail Handling
        2. 2.8.4.2 BSL Configuration CRC Fail Handling
        3. 2.8.4.3 16-bit Pattern Match for Critical Fields
  6. 3Secure Boot
    1. 3.1 MCUBoot
    2. 3.2 ROM-based Secure Boot
      1. 3.2.1 ROM-based Secure Boot Flow
      2. 3.2.2 Customer Key Storage
        1. 3.2.2.1 Key Revocation Using the DSSM
        2. 3.2.2.2 Key Revocation Using the Firmware Update
      3. 3.2.3 Anti‑rollback Protection
    3. 3.3 CSC-based Secure Boot
      1. 3.3.1 CSC-based Secure Boot Flow
      2. 3.3.2 FLASH Memory Map
      3. 3.3.3 CSC Key Storage
        1. 3.3.3.1 Key Storage for CSC-based Secure Boot
        2. 3.3.3.2 KEYSTORE for AES
      4. 3.3.4 Bank Swap
      5. 3.3.5 CSC Protection
    4. 3.4 Two Stage Secure Boot
      1. 3.4.1 Two Stage Secure Boot Flow
  7. 4Secure Execution Environment
    1. 4.1 TrustZone
      1. 4.1.1 Implementation Defined Attribution Unit
      2. 4.1.2 Security Attribution Unit
        1. 4.1.2.1 Defining a Region as Secure
      3. 4.1.3 TrustZone Software Development
        1. 4.1.3.1 Defining Functions as Secure and Non-secure
    2. 4.2 Memory Protection Unit
      1. 4.2.1 TrustZone and MPU
    3. 4.3 Global Security Controller
      1. 4.3.1 GSC Memory Configuration
        1. 4.3.1.1 Security Exceptions Through the GSC and SAU
        2. 4.3.1.2 Privilege Exceptions With GSC and MPU
  8. 5Secure Storage
    1. 5.1 Write Erase Protection
      1. 5.1.1 Global Security Controller Configuration on WEP
      2. 5.1.2 NONMAIN FLASH Configuration on WEP
    2. 5.2 FLASH Hide Protection
      1. 5.2.1 Global Security Controller Configuration on HDP
    3. 5.3 Secure Key Storage
    4. 5.4 Data Integrity Verification
    5. 5.5 Secure and Privilege Protection
    6. 5.6 Hardware Monotonic Counter
  9. 6Security Modules
    1. 6.1 AESADV
      1. 6.1.1 AES Overview
      2. 6.1.2 AES Usage
        1. 6.1.2.1 Configuration
        2. 6.1.2.2 Setup
        3. 6.1.2.3 Operation
    2. 6.2 Keystore
      1. 6.2.1 Overview
      2. 6.2.2 Keystore Usage
        1. 6.2.2.1 Configuration
        2. 6.2.2.2 Setup
        3. 6.2.2.3 Operation
    3. 6.3 SHA2
      1. 6.3.1 SHA Introduction
        1. 6.3.1.1 SHA Features
      2. 6.3.2 SHA Performance
      3. 6.3.3 SHA Usage
        1. 6.3.3.1 Configuration
        2. 6.3.3.2 Setup
        3. 6.3.3.3 Operation
    4. 6.4 PKA
      1. 6.4.1 PKA Introduction
        1. 6.4.1.1 PKA features
      2. 6.4.2 PKA Usage
        1. 6.4.2.1 Configuration
        2. 6.4.2.2 Setup
        3. 6.4.2.3 Operation
    5. 6.5 PQC
      1. 6.5.1 ML-DSA
        1. 6.5.1.1 ML-DSA Introduction
        2. 6.5.1.2 ML-DSA Usage
          1. 6.5.1.2.1 Configuration
          2. 6.5.1.2.2 Setup
          3. 6.5.1.2.3 Operation
  10. 7Revision History

4.1.1 Implementation Defined Attribution Unit

The implementation defined attribution unit (IDAU) is defined by TI and is referenced in the CPU section of the MSPM33C3-Series 160MHz Microcontrollers Technical Reference Manual. It is important to know how the IDAU is configured since the IDAU's configuration will be used with the SAU to configure the final security level of a region. For example in the MSPM33C32 devices the IDAU is configured such that when the 8th bit of the address is 1 the memory region is defined as non-secure callable and when it's 0 its only non-secure. For example the address 0x1000.0000 is defined as NSC.

The IDAU and SAU are both used to determine the final level of security. The highest security level out of the two is set as the final attributed level of security. For an example of this on the MSPM33C321A see Figure 4-1.

MSPM33C MSPM33C321A IDAU and SAU on MSPM33C321A Configuration Example Figure 4-1 IDAU and SAU on MSPM33C321A Configuration Example