CTR = CMPB
CTR = CMPA
CTR_Dir
CTR = 0
CTR = PRD
Dead
Band
(DB)
Counter
Compare
(CC)
Action
Qualifier
(AQ)
EPWMxA
EPWMxB
CTR = CMPB
CTR = 0
EPWMxINT
EPWMxA
EPWMxB
TZ1 to TZn
CTR = CMPA
Time-Base
(TB)
CTR = PRD
CTR = 0
CTR_Dir
EPWMxSYNCI
EPWMxSYNCO
EPWMxTZINT
PWM-
chopper
(PC)
Event
Trigger
and
Interrupt
(ET)
Trip
Zone
(TZ)
GPIO
MUX
Interrupt
controller
Interrupt
controller
Enhanced PWM (ePWM) Module
15.2.2.5 Action-Qualifier (AQ) Submodule
shows the action-qualifier (AQ) submodule (see shaded block) in the ePWM system. The
action-qualifier submodule has the most important role in waveform construction and PWM generation. It
decides which events are converted into various action types, thereby producing the required switched
waveforms at the EPWMxA and EPWMxB outputs.
Figure 15-23. Action-Qualifier Submodule
15.2.2.5.1 Purpose of the Action-Qualifier Submodule
The action-qualifier submodule is responsible for the following:
•
Qualifying and generating actions (set, clear, toggle) based on the following events:
–
CTR = PRD: Time-base counter equal to the period (TBCNT = TBPRD)
–
CTR = 0: Time-base counter equal to zero (TBCNT = 0000h)
–
CTR = CMPA: Time-base counter equal to the counter-compare A register (TBCNT = CMPA)
–
CTR = CMPB: Time-base counter equal to the counter-compare B register (TBCNT = CMPB)
•
Managing priority when these events occur concurrently
•
Providing independent control of events when the time-base counter is increasing and when it is
decreasing.
15.2.2.5.2 Controlling and Monitoring the Action-Qualifier Submodule
lists the registers used to control and monitor the action-qualifier submodule.
Table 15-15. Action-Qualifier Submodule Registers
Acronym
Register Description
Address Offset
Shadowed
AQCTLA
Action-Qualifier Control Register For Output A (EPWMxA)
16h
No
AQCTLB
Action-Qualifier Control Register For Output B (EPWMxB)
18h
No
AQSFRC
Action-Qualifier Software Force Register
1Ah
No
AQCSFRC
Action-Qualifier Continuous Software Force
1Ch
Yes
1516Pulse-Width Modulation Subsystem (PWMSS)
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated