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

2.4 Comparison of Different PWM Signal Capture Design

Table 2-1 listed the differences between two PWM capture methods, according to the table PWM signal capture with TIMx CC block realized by MCU hardware. PWM signal capture with GPIO interrupt can reach to higher accuracy and feasibility:

Table 2-1 PWM Signal Capture Methods Comparisons
Items PWM Signal Capture with TIMx CC Block PWM Signal Capture with GPIO Interrupt
Capture Delay Decided by timer capture block Decided by interrupt and software
Capture error Decided by timer capture block Can be managed by SW
Absolute error Varies according to PWM frequency and duty cycle Under 1%, simple to compensate the error