CTR = CMPB
CTR = CMPA
CTR_Dir
CTR = 0
CTR = PRD
Dead
Band
(DB)
Counter
Compare
(CC)
Action
Qualifier
(AQ)
EPWMA
EPWMB
CTR = CMPB
CTR = 0
EPWMxINT
EPWMxA
EPWMxB
TZ1
TZn
to
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)
Enhanced PWM (ePWM) Module
15.2.2.9 Event-Trigger (ET) Submodule
shows the event-trigger (ET) submodule in the ePWM system. The event-trigger submodule
manages the events generated by the time-base submodule and the counter-compare submodule to
generate an interrupt to the CPU.
Figure 15-44. Event-Trigger Submodule
15.2.2.9.1 Purpose of the Event-Trigger Submodule
The key functions of the event-trigger submodule are:
•
Receives event inputs generated by the time-base and counter-compare submodules
•
Uses the time-base direction information for up/down event qualification
•
Uses prescaling logic to issue interrupt requests at:
–
Every event
–
Every second event
–
Every third event
•
Provides full visibility of event generation via event counters and flags
15.2.2.9.2 Controlling and Monitoring the Event-Trigger Submodule
The key registers used to configure the event-trigger submodule are shown in
Table 15-38. Event-Trigger Submodule Registers
Acronym
Register Description
Address Offset
Shadowed
ETSEL
Event-Trigger Selection Register
32h
No
ETPS
Event-Trigger Prescale Register
34h
No
ETFLG
Event-Trigger Flag Register
36h
No
ETCLR
Event-Trigger Clear Register
38h
No
ETFRC
Event-Trigger Force Register
3Ah
No
1546Pulse-Width Modulation Subsystem (PWMSS)
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated