49.3. PWM Output

49.3.1. Overview

This project demonstrates how to configure and output several different types of PWM waveforms through MCU pins.

The demo includes the following PWM output types:

  • Forced output (high/low level)

  • Edge-aligned PWM

  • Edge-aligned PWM with fault mode

  • Center-aligned PWM

  • Center-aligned complementary PWM

  • Edge-aligned PWM with jitter

49.3.2. Hardware Requirements

  • Dual Channel Oscilloscope

  • Serial terminal for debugging output

  • Connect PWM output pins according to your board model (refer to board information)

49.3.3. Configuration

  • Install the serial terminal and configure it according to board information

  • Connect PWM output pins (PWM_P0 and PWM_P1) as specified in board resource

  • Connect oscilloscope probes to PWM output pins

49.3.4. Running the Demo

After power on, the oscilloscope will display the following waveforms in sequence:

  1. Forced output: - Both P0 and P1 output high level for 5 seconds - Both P0 and P1 output low level for 5 seconds

  2. Edge-aligned PWM: - P0: Target waveform with duty cycle varying from 0% to 100% and back - P1: Reference waveform with 50% duty cycle

  3. Edge-aligned PWM with fault mode: - Similar to edge-aligned PWM but with fault protection enabled - Demonstrates PWM behavior under fault conditions

  4. Center-aligned PWM: - P0: Target waveform with duty cycle varying from 0% to 100% and back - P1: Reference waveform with 50% duty cycle

  5. Center-aligned complementary PWM: - P0 and P1: Complementary waveforms with duty cycle varying from 0% to 100% and back - Includes dead time between complementary signals

  6. Edge-aligned PWM with jitter: - P0: Target waveform with duty cycle varying from 0% to 100% and back - P1: Reference waveform with 50% duty cycle - Includes jitter effect for demonstration

Serial port output will show the progress of each test:

pwm example

>> Test force PWM output on P0 and P1
Output high
Output low

>> Generate edge aligned waveform
Two waveforms will be generated, PWM P0 is the target waveform
whose duty cycle will be updated from 0 - 100 and back to 0; PWM P1 is a reference

>> Generate edge aligned waveform and fault mode enable
Two waveforms will be generated, PWM P0 is the target waveform
whose duty cycle will be updated from 0 - 100 and back to 0; PWM P1 is a reference

>> Generate central aligned waveform
Two waveforms will be generated, PWM P0 is the target waveform
whose duty cycle will be updated from 0 - 100 and back to 0; PWM P1 is a reference

>> Generate central aligned waveform in pair
Two waveforms will be generated in pair, PWM P0 and P1 are target
waveforms whose duty cycle will be updated from 0 - 100 and back to 0

>> Generate edge aligned jit waveform
Two waveforms will be generated, PWM P0 is the target waveform
whose duty cycle will be updated from 0 - 100 and back to 0; PWM P1 is a reference

test done

Note

The demo runs through all PWM output types once. To observe the waveforms again, you need to reset and run the program again.