Texas Instruments 28xxx Action-Qualifier AQ Submodule, Purpose of the Action-Qualifier Submodule

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Action-Qualifier (AQ) Submodule

2.4Action-Qualifier (AQ) Submodule

Figure 2-17shows the action-qualifier (AQ) submodule (see shaded block) in the ePWM system.

Figure 2-17. Action-Qualifier Submodule

EPWMxSYNCI

EPWMxSYNCO

Time-Base

(TB)

Counter

Compare

(CC)

CTR = PRD

CTR = 0

CTR_Dir

CTR = CMPA

CTR = CMPB

Action

Qualifier

(AQ)

EPWMxA

EPWMxB

	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
PIE	EPWMxTZINT

EPWMxINT

EPWMxSOCA

EPWMxSOCB

EPWMxA

EPWMxB

TZ1 to TZ6

PIE

ADC

GPIO MUX

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.

2.4.1 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 (TBCTR = TBPRD).

–CTR = Zero: Time-base counter equal to zero (TBCTR = 0x0000)

–CTR = CMPA: Time-base counter equal to the counter-compare A register (TBCTR = CMPA)

–CTR = CMPB: Time-base counter equal to the counter-compare B register (TBCTR = 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. .

2.4.2Action-Qualifier Submodule Control and Status Register Definitions

The action-qualifier submodule operation is controlled and monitored via the registers in Table 2-6.

Table 2-6. Action-Qualifier Submodule Registers

Register	Address offset	Shadowed	Description
Name
AQCTLA	0x000B	No	Action-Qualifier Control Register For Output A (EPWMxA)
AQCTLB	0x000C	No	Action-Qualifier Control Register For Output B (EPWMxB)
AQSFRC	0x000D	No	Action-Qualifier Software Force Register
AQCSFRC	0x000E	Yes	Action-Qualifier Continuous Software Force

SPRU791D–November 2004–Revised October 2007	ePWM Submodules	37
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