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
2.8.1.3.1 Locking the Application (MAIN) Flash Memory

MSPM33 MCUs implement a static write protection scheme(using the GSC) to lock out user defined sectors in the MAIN flash region from any program or erase operations at run time. The desired static write protection scheme is configured as a part of the boot security policies in the NONMAIN flash region. During boot process, ROM bootcode sets up GSC to apply write erase protection on defined sectors.

Note: GSC can be configured by boot code in ROM or user application in run time. User can also configure write erase protection in GSC during application code. Please refer Section 5.1 for more details.
Note: Access type of GSC registers for static write protection is 'R/W1S'. 'W1S' is that register bit can only be set from 0 to 1, and register can only be reset by BOOTRST or higher reset type, which means the applied write protection can not be directly removed. So if the static write erase protection is set up in ROM bootcode, it cannot be removed by application then.

Static write protection enables placement of a fixed, user-defined, application in the flash memory that has the following characteristics:

  • Once programmed and locked, the application is not modifiable by the application code or ROM bootloader
  • If placed at the beginning of the flash memory, the application is the first code that executes when the ROM boot configuration routine transfers execution to the user application

MSPM33 static write protection supports both characteristics, which must be satisfied to implement a secure boot image manager.

Any sector that is configured in the NONMAIN to be write-locked is functionally immutable when the boot configuration routine transfers execution to either the bootstrap loader or the user application code in MAIN flash. Any attempt to program or erase a statically protected sector by the application code or the bootstrap loader results in a hardware flash operation error, and the sector is not modified.

While static write protection prevents any modification by application code or the bootloader, a mass erase or factory reset command sent through the SWD interface is honored. If this behavior is not desired, the mass erase or factory reset SWD commands can be protected with unique passwords or disabled(see the Section 2.8.1.1). To completely remove any means of modifying statically write protected MAIN flash sectors, the mass erase and factory reset commands (or the SW-DP) must be disabled, and the NONMAIN boot configuration memory must also be statically write protected to prevent application code from changing the underling write protection scheme by modifying the contents NONMAIN region. This is discussed in the following section.