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

3.1 Identifying Rising and Falling Edge

GPIO interrupt is triggered on both GPIO rising edge and falling edge. Read the GPIO state to identify whether the GPIO rising edge triggers the interrupt or GPIO falling edge triggers the interrupt according to Table 3-1.

Table 3-1 GPIO Falling and Rising Edge Interrupt
GPIO State GPIO Edge to Trigger the Interrupt
GPIO input = low level Falling edge
GPIO input = high levl Rising edge