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Event-Trigger (ET) Submodule

Figure 2-37. Trip-Zone Submodule Interrupt Logic

TZFLG[INT]TZFLG[CBC]

TZCLR[INT]

EPWMx_TZINT (PIE)

Clear

Latch

Set

Generate interrupt pulse￿when input=1

Clear

Latch

Set

TZEINT[CBC]

TZFLG[OST]

Clear

Latch

Set

TZEINT[OST]

TZCLR[CBC]

CBC

trip￿event

TZCLR[OST]

OSHT trip￿event

2.8Event-Trigger (ET) 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 and ADC start of conversion at:

Every event

Every second event

Every third event

Provides full visibility of event generation via event counters and flags

Allows software forcing of Interrupts and ADC start of conversion

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 and/or a start of conversion pulse to the ADC when a selected event occurs. Figure 2-38illustrates where the event-trigger submodule fits within the ePWM system.

Figure 2-38. Event-Trigger Submodule

EPWMxSYNCI

EPWMxSYNCO

Time-Base (TB)

Counter

Compare

(CC)

CTR￿=￿PRD

CTR￿=￿0

CTR_Dir

CTR￿=￿CMPA

CTR￿=￿CMPB

Action

Qualifier

(AQ)

EPWMA

EPWMB

 

CTR￿=￿PRD

Event

 

CTR￿=￿￿0

 

Trigger

CTR￿=￿CMPA

and

 

CTR￿=￿CMPB

Interrupt

 

CTR_Dir

(ET)

 

 

 

Dead

PWM-

Trip

Band

chopper

Zone

(DB)

(PC)

(TZ)

 

 

 

CTR￿=￿0

 

EPWMxTZINT

 

EPWMxINT

EPWMxSOCA

EPWMxSOCB

EPWMxA

EPWMxB

TZ1 to￿TZ6

SPRU791D–November 2004–Revised October 2007

ePWM Submodules

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Texas Instruments 28xxx, TMS320x28xx manual Event-Trigger ET Submodule, Trip-Zone Submodule Interrupt Logic