SPRADL7 July   2025 F28E120SC

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 Introduction
  5. 2 Key Differences Between EPWM and MCPWM
  6. 3 Time-Base Submodule Differences
    1. 3.1 Register Differences
    2. 3.2 Driverlib Differences
  7. 4 Counter-Compare Submodule Differences
    1. 4.1 Register Differences
    2. 4.2 Driverlib Differences
  8. 5 Action-Qualifier Submodule Differences
    1. 5.1 Register Differences
    2. 5.2 Driverlib Differences
  9. 6 Dead-Band Submodule Differences
    1. 6.1 Register Differences
    2. 6.2 Driverlib Differences
  10. 7 Trip-Zone Submodule Differences
    1. 7.1 Register Differences
    2. 7.2 Driverlib Differences
  11. 8 Event-Trigger Submodule Differences
    1. 8.1 Register Differences
    2. 8.2 Driverlib Differences
  12. 9 Global Load Differences
    1. 9.1 Register Differences
    2. 9.2 Driverlib Differences
  13. 10Summary
  14. 11References

Abstract

In the Application-Specific Microcontrollers (ASM) device family, there are different types of PWM modules: EPWM (Enhanced Pulse-Width Modulator) and MCPWM (Multi-Channel Pulse-Width Modulator) module. Most C2000 devices such as F2837xD, F28003x and F28P55x have utilized the EPWM module. The F28E12x devices are the first to utilize the MCPWM module.

The MCPWM module was designed as a low-cost version of the EPWM module specifically for motor control applications. More specifically, a single MCPWM module is intended to drive a 3-phase motor. For this reason, a single MCPWM instance can have up to six outputs unlike the EPWM module which only has two. Still, the core functionality of the MCPWM module remains the same.

Due to the reduced feature-set of MCPWM, and the combination of three PWM pairs into a single MCPWM instance, the programming procedure for the two modules have significant differences which are addressed in this document. The programming procedures and feature differences for the time-base, counter-compare, action-qualifier, and other submodules are detailed. The recommended workarounds to successfully migrate an EPWM-based application to MCPWM are described in this application note.