UP
DOWN
UP
DOWN
2
0
3
4
1
2
3
1
2
0
3
4
1
2
0
3
1
TBCTR
TBCTR Direction
EPWMxA/EPWMxB
Case 2:
CMPA = 3, 25% Duty
Case 3:
CMPA = 2, 50% Duty
Case 3:
CMPA = 1, 75% Duty
Case 4:
CMPA = 0, 100% Duty
Case 1:
CMPA = 4, 0% Duty
EPWMxA/EPWMxB
EPWMxA/EPWMxB
EPWMxA/EPWMxB
EPWMxA/EPWMxB
Mode: Up-Down Count
TBPRD = 4
CAU = SET, CAD = CLEAR
0% - 100% Duty
ePWM Submodules
2020
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
Enhanced Pulse Width Modulator (ePWM) Module
Figure 35-20. Up-Down-Count Mode Symmetrical Waveform
The PWM waveforms in
through
show some common action-qualifier
configurations. The C-code samples in
through
shows how to configure an
ePWM module for each case. Some conventions used in the figures and examples are as follows:
•
TBPRD, CMPA, and CMPB refer to the value written in their respective registers. The active register,
not the shadow register, is used by the hardware.
•
CMPx, refers to either CMPA or CMPB.
•
EPWMxA and EPWMxB refer to the output signals from ePWMx
•
Up-Down means Count-up-and-down mode, Up means up-count mode and Dwn means down-count
mode
•
Sym = Symmetric, Asym = Asymmetric
contains a code sample showing initialization and run time for the waveforms in