SDAA040 July   2025 MSPM0C1104

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 PWM Signal Capture Introduction
    2. 1.2 MSPM0C110x Introduction
  5. 2PWM Signal Capture
    1. 2.1 PWM Signal Capture Methods
    2. 2.2 PWM Signal Capture with TIMx CC Block
    3. 2.3 PWM Signal Capture with GPIO Interrupt
    4. 2.4 Comparison of Different PWM Signal Capture Design
  6. 3Software Realization
    1. 3.1 Identifying Rising and Falling Edge
    2. 3.2 Time Order Classification
    3. 3.3 Signal Filter and Result Calculation
  7. 4System Test
    1. 4.1 Test Setup
    2. 4.2 Variable Monitor
    3. 4.3 PWM Signal Capture Resolution Test and Comparison
  8. 5Summary
  9. 6References

5 Summary

This application note proposes the workaround for the PWM capture error with MSPM0C110x series MCU with only one timer and one GPIO. This workaround can also identify 100% and 0% PWM duty cycles without any additional work. The test results show that the method can keep the capture error below 1% in 100Hz to 10KHz PWM frequency range. The test results also show the robustness in PWM duty <1% and >99% corner cases.