SDAA220 January   2026 MSPM0G3519

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction to LIN Protocol
    1. 1.1 Break Field
    2. 1.2 SYNC Byte Field
    3. 1.3 PID Field
    4. 1.4 Data
    5. 1.5 Checksum
  5. 2Initial Baud Rate Setting
  6. 3Realization of LIN Protocol MSPM0 UART/ UNICOMM UART
    1. 3.1 LIN Transmission
      1. 3.1.1 Break Field
      2. 3.1.2 Sync Field
      3. 3.1.3 PID Field
      4. 3.1.4 Data Field
      5. 3.1.5 Checksum
    2. 3.2 LIN Reception
      1. 3.2.1 Break Field Detection
      2. 3.2.2 SYNC Field Validation
    3. 3.3 LIN Transceiver
  7. 4Automatic Baud Rate Detection
    1. 4.1 Procedure to Measure Bit-width using MSPM0 UART / UNICOMM UART
    2. 4.2 Calculation of Correct Baud Rate
      1. 4.2.1 Crystal Error at Responder Node
  8. 5Deviation in Baud Rate after Synchronization
  9. 6References

Abstract

This application note provides a detailed overview of the automatic baud rate detection mechanism provided by MSPM0 UART and UNICOMM UART receiver LIN nodes. The information presented is specifically relevant to devices that achieve the required clock frequency tolerance through synchronization methods. In MSPM0 UART and UNICOMM UART modules, automatic baud rate detection is accomplished using a combination of hardware and software solutions.

This document begins by outlining the tolerance requirements specified by the LIN (Local Interconnect Network) protocol. It then describes how MSPM0 UART/UNICOMM UART modules are designed to meet these tolerance limits while reliably detecting variable baud rates. The application note breaks down the synchronization process, enabling accurate data reception even in systems with potential clock inaccuracies. Integration details, practical implementation methodologies, and application-specific considerations are covered to aid embedded system designers in leveraging automatic baud rate detection effectively within their projects.