ePWM Submodules
2000
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
Enhanced Pulse Width Modulator (ePWM) Module
Table 35-1. ePWM Module Control and Status Register Set Grouped by Submodule (continued)
Name
Address
Offset
(1)
Size
(x16)
Shadow
Privileged
Mode Write
Only?
Description
Digital Compare Event Registers
DCACTL
60h
1
No
Yes
Digital Compare A Control Register
DCTRIPSEL
62h
1
No
Yes
Digital Compare Trip Select Register
DCFCTL
64h
1
No
Yes
Digital Compare Filter Control Register
DCBCTL
66h
1
No
Yes
Digital Compare B Control Register
DCFOFFSET
68h
1
Writes
No
Digital Compare Filter Offset Register
DCCAPCTL
6Ah
1
No
Yes
Digital Compare Capture Control Register
DCFWINDOW
6Ch
1
No
No
Digital Compare Filter Window Register
DCFOFFSETCNT
6Eh
1
No
No
Digital Compare Filter Offset Counter Register
DCCAP
70h
1
Yes
No
Digital Compare Counter Capture Register
DCFWINDOWCNT
72h
1
No
No
Digital Compare Filter Window Counter Register
35.2 ePWM Submodules
Eight submodules are included in every ePWM peripheral. Each of these submodules performs specific
tasks that can be configured by software.
35.2.1 Overview
lists the eight key submodules together with a list of their main configuration parameters. For
example, if you need to adjust or control the duty cycle of a PWM waveform, then you should see the
counter-compare submodule in
for relevant details.
Table 35-2. Submodule Configuration Parameters
Submodule
Configuration Parameter or Option
Time-base (TB)
• Scale the time-base clock (TBCLK) relative to the system clock (VCLK3).
• Configure the PWM time-base counter (TBCTR) frequency or period.
• Set the mode for the time-base counter:
–
count-up mode: used for asymmetric PWM
–
count-down mode: used for asymmetric PWM
–
count-up-and-down mode: used for symmetric PWM
• Configure the time-base phase relative to another ePWM module.
• Synchronize the time-base counter between modules through hardware or software.
• Configure the direction (up or down) of the time-base counter after a synchronization event.
• Configure how the time-base counter will behave when the device is halted by an emulator.
• Specify the source for the synchronization output of the ePWM module:
–
Synchronization input signal
–
Time-base counter equal to zero
–
Time-base counter equal to counter-compare B (CMPB)
–
No output synchronization signal generated.
Counter-compare (CC)
• Specify the PWM duty cycle for output EPWMxA and/or output EPWMxB
• Specify the time at which switching events occur on the EPWMxA or EPWMxB output
Action-qualifier (AQ)
• Specify the type of action taken when a time-base or counter-compare submodule event occurs:
–
No action taken
–
Output EPWMxA and/or EPWMxB switched high
–
Output EPWMxA and/or EPWMxB switched low
–
Output EPWMxA and/or EPWMxB toggled
• Force the PWM output state through software control
• Configure and control the PWM dead-band through software