SLUUDI6 December   2025 MSPM33C321A

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Overview of BSL Features
    2. 1.2 Terminology
    3. 1.3 Additional resources
  5. 2BSL Architecture
    1. 2.1 Design
      1. 2.1.1 Timeout Feature
        1. 2.1.1.1 Interface Autodetection
        2. 2.1.1.2 Command Reception
    2. 2.2 BSL Invocation
      1. 2.2.1 Application Request
      2. 2.2.2 GPIO Based Invocation
      3. 2.2.3 Debug Mailbox Command
      4. 2.2.4 Other BSL Invocation Methods
        1. 2.2.4.1 Pre-Boot Application Verification
        2. 2.2.4.2 Blank Device Handling
    3. 2.3 Memory
      1. 2.3.1 SRAM Memory Usage
    4. 2.4 BSL Non-Main Configuration
      1. 2.4.1  BSL Configuration ID
      2. 2.4.2  BSL Interface Pins (BLINTERFACE_PINS)
      3. 2.4.3  BSL Invoke Pin Configuration (BSLPIN_INVOKE)
      4. 2.4.4  Memory Readout Configuration
      5. 2.4.5  BSL Password
      6. 2.4.6  Application Revision Pointer
      7. 2.4.7  Security Alert Level
      8. 2.4.8  UART Baud Rate
      9. 2.4.9  I2C Slave Address
      10. 2.4.10 Configuration CRC
    5. 2.5 Changing BSL Configuration
      1. 2.5.1 Reference
      2. 2.5.2 Using SysConfig and Code Composer Studio (CCS)
      3. 2.5.3 Using Debug Interface
  6. 3Bootloader Protocol
    1. 3.1 Packet Format
    2. 3.2 BSL Protocol
      1. 3.2.1 BSL Acknowledgment
      2. 3.2.2 Peripheral Configuration
        1. 3.2.2.1 UART
        2. 3.2.2.2 I2C
        3. 3.2.2.3 CRC
    3. 3.3 Bootloader Core Commands
      1. 3.3.1  Connection
      2. 3.3.2  Get Device Info
      3. 3.3.3  Unlock Bootloader
      4. 3.3.4  Program Data
      5. 3.3.5  Program Data Fast
      6. 3.3.6  Readback Data
      7. 3.3.7  Flash Range Erase
      8. 3.3.8  Mass Erase
      9. 3.3.9  Factory Reset
      10. 3.3.10 Standalone Verification
      11. 3.3.11 Start Application
      12. 3.3.12 Change Baud Rate
    4. 3.4 Bootloader Core Response
      1. 3.4.1 BSL Core Message
      2. 3.4.2 Detailed Error
      3. 3.4.3 Memory Readback
      4. 3.4.4 Device Info
      5. 3.4.5 Standalone Verification
    5. 3.5 Bootloader Security
      1. 3.5.1 Password Protected Commands
        1. 3.5.1.1 Security Alert
      2. 3.5.2 BSL Entry
  7. 4Sample Program Flow with Bootloader
  8. 5Revision History

BSL Core Message

Structure

HeaderLengthRSPDataCRC32
0x080x020x000x3BMSGC1C2C3C4

Description

For some commands, BSL sends the message response to the host, which indicates the status of the processed command. The table lists all the possible messages from the BSL.

MSGMeaningPossible Cause(1)
0x00Operation Successful
0x01BSL Locked errorThe BSL is not yet unlocked with Bootloader unlock password command or After BSL unlock, a timeout would have occurred in the command reception phase
0x02BSL password errorIncorrect password has been sent to unlock bootloader.
0x03Multiple BSL password error. Security Alert action is taken.Incorrect password has been sent to unlock bootloader 3 times.
0x04Unknown CommandThe command given to the BSL was not recognized as valid command
0x05Invalid memory rangeThe given memory range is invalid.
0x06Invalid commandThe command given to the BSL is a known command but it is invalid at that time instant and cannot be processed.

0x07

Factory reset disabledFactory reset is disabled in the BCR configuration

0x08

Factory reset password errorIncorrect or no password has been sent with factory reset command, when the BCR configuration has factory reset 'Enabled with password'

0x09

Read out errorMemory read out be disabled in BCR configuration

0x0A

Invalid address or length alignmentStart address or data length for the flash programming is not 8-byte aligned

0x0B

Invalid length for standalone verificationData size sent for standalone verification is less than 1KB
Possible causes listed here, are not the only reason for the status or error. It only lists the probable software reasons for the error, that can be corrected by the host.