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 TZnto
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
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15.2.2.9 Event-Trigger (ET) Submodule
Figure 15-44 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:
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
1546
Pulse-Width Modulation Subsystem (PWMSS) SPRUH73H–October 2011–Revised April 2013
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