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2.4.3Action-QualifierEventPriority
Action-Qualifier(AQ)Submodule
ItispossiblefortheePWMactionqualifiertoreceivemorethanoneeventatthesametime.Inthiscase
eventsareassignedaprioritybythehardware.Thegeneralruleiseventsoccurringlaterintimehavea
higherpriorityandsoftwareforcedeventsalwayshavethehighestpriority.Theeventprioritylevelsfor
up-down-countmodeareshowninTable2-8.Aprioritylevelof1isthehighestpriorityandlevel7isthe
lowest.TheprioritychangesslightlydependingonthedirectionofTBCTR.
Table2-8.Action-QualifierEventPriorityforUp-Down-CountMode
PriorityLevelEventIfTBCTRisIncrementingEventIfTBCTRisDecrementing
TBCTR=ZerouptoTBCTR=TBPRDTBCTR=TBPRDdowntoTBCTR=1
1(Highest)SoftwareforcedeventSoftwareforcedevent
2CounterequalsCMPBonup-count(CBU)CounterequalsCMPBondown-count(CBD)
3CounterequalsCMPAonup-count(CAU)CounterequalsCMPAondown-count(CAD)
4CounterequalszeroCounterequalsperiod(TBPRD)
5CounterequalsCMPBondown-count(CBD)
(1)
CounterequalsCMPBonup-count(CBU)
(1)
6(Lowest)CounterequalsCMPAondown-count(CAD)
(1)
CounterequalsCMPAonup-count(CBU)
(1)
(1)
Tomaintainsymmetryforup-down-countmode,bothup-events(CAU/CBU)anddown-events(CAD/CBD)canbegeneratedfor
TBPRD.Otherwise,up-eventscanoccuronlywhenthecounterisincrementinganddown-eventscanoccuronlywhenthe
counterisdecrementing.
Table2-9showstheaction-qualifierpriorityforup-countmode.Inthiscase,thecounterdirectionisalways
definedasupandthusdown-counteventswillneverbetaken.
Table2-9.Action-QualifierEventPriorityforUp-CountMode
PriorityLevelEvent
1(Highest)Softwareforcedevent
2Counterequaltoperiod(TBPRD)
3CounterequaltoCMPBonup-count(CBU)
4CounterequaltoCMPAonup-count(CAU)
5(Lowest)CounterequaltoZero
Table2-10showstheaction-qualifierpriorityfordown-countmode.Inthiscase,thecounterdirectionis
alwaysdefinedasdownandthusup-counteventswillneverbetaken.
Table2-10.Action-QualifierEventPriorityforDown-CountMode
PriorityLevelEvent
1(Highest)Softwareforcedevent
2CounterequaltoZero
3CounterequaltoCMPBondown-count(CBD)
4CounterequaltoCMPAondown-count(CAD)
5(Lowest)Counterequaltoperiod(TBPRD)
Itispossibletosetthecomparevaluegreaterthantheperiod.Inthiscasetheactionwilltakeplaceas
showninTable2-11.
ePWMSubmodules 40SPRU791D–November2004–RevisedOctober2007
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