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

3 Time-Base Submodule Differences

The Time-Base submodule is responsible for the PWM frequency and synchronization between EPWM or MCPWM modules. This section details differences between the Time-Base Submodule in EPWM and MCPWM.

The feature differences of the MCPWM Time-Base submodule when compared to EPWM are as follows:

  • Addition of memory mapped Time-Base Period shadow register (TBPRDS). When shadow loading is enabled, this register must be written to directly instead of the active register (TBPRD).
  • Clock divider and high speed clock divider combined into single divider (TBCTL.CLKDIV) on MCPWM
  • One-shot sync feature removed on MCPWM
  • Down-Count mode removed on MCPWM
  • CTRMAX flag removed
  • Up to 3 PWM pairs share the same counter (phase-shifting between PWM pairs must be implemented via Counter-Compare Submodule)
EPWM Time-Base Submodule Block Diagram Figure 3-1 EPWM Time-Base Submodule Block Diagram
MCPWM Time-Base Submodule Block Diagram Figure 3-2 MCPWM Time-Base Submodule Block Diagram