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2.1.4CaptureChannelReset
2.1.5DisplayChannelReset
2.2InterruptOperation
InterruptOperation
Note:TheVPRSTbitmaytakeseveralclockcyclestoclearto0.TheVPRSTbitshouldbe
polledtomakesurethebitisclearedpriortowritingtothevideoportregisters.
OncetheportisconfiguredandtheVPHLTbitiscleared,thesettingofotherVPCTLbits
(exceptVPRST)isdisabled.TheVCLK2outputmayalsobedrivenatthistime,ifdisplay
modeisselected.VCTL1-3mustremaininahigh-impedancestateunlessenabledas
GPIO,sinceinternal/externalsyncisselectedthroughVDCTL.
AsoftwareresetmaybeperformedonasinglecapturechannelbysettingtheRSTCHbitinVCxCTL.This
resetrequiresthatthechannelVCLKINbetransitioning.Oncapturechannelreset:
•NonewEDMAeventsaregenerated.
•Peripheralbusaccessesareacknowledged(RREADYreturned)topreventEDMAlock-up.(Anyvalue
returnedonreads).
•Channelcaptureregistersaresettotheirdefaultvalues.
•ChannelcaptureFIFOisflushed(pointersreset).
•TheVCENbitinVCxCTLisclearedto0.
•TheRSTCHbitself-clearsto0aftercompletionoftheabove.
OncetheportisconfiguredandtheVCENbitisset,thesettingofotherVCxCTLbits(exceptVCEN,
RSTCH,andBLKCAP)isprohibitedandthecapturecountersbegincounting.WhenBLKCAPiscleared,
datacaptureandeventgenerationmaybegin.
AsoftwareresetmaybeperformedonthedisplaychannelbysettingtheRSTCHbitinVDCTL.Thisreset
requiresthatthechannelVCLKINbetransitioning.Ondisplaychannelreset:
•NonewEDMAeventsaregenerated.
•Peripheralbusaccessesareacknowledged(WREADYreturned)topreventEDMAlock-up.(Writedata
maybewrittenintotheFIFOordiscarded.)
•Channeldisplayregistersaresettotheirdefaultvalues.
•ChanneldisplayFIFOisflushed(pointersreset).
•TheVDENbitinVDCTLisclearedto0.
•TheRSTCHbitself-clearsto0aftercompletionoftheabove.
OncetheportisconfiguredandtheVDENbitisset,thesettingofotherVDCTLbits(exceptVDEN,
RSTCH,andBLKDIS)isprohibitedandthedisplaycountersbegincounting.Dataoutputsaredriven(with
defaultvalue,blanking,andcontrolcodesasappropriateandanycontroloutputsaredriven).Whenthe
BLKDISbitiscleared,eventgenerationmaybeginandFIFOdatadisplayed.
ThevideoportgeneratesaninterrupttotheDSPcoreafteranyofthefollowingeventsoccur:
•Capturecomplete(CCMPx)bitisset.
•Captureoverrun(COVRx)bitisset.
•Synchronizationbyteerror(SERRx)bitisset.
•Verticalinterrupt(VINTxn)bitisset.
•Shortfielddetect(SFDx)bitisset.
•Longfielddetect(LFDx)bitisset.
•STCabsolutetime(STC)bitisset.
•STCtickcounterexpired(TICK)bitisset.
•Displaycomplete(DCMP)bitisset.
•Displayunder-run(DUND)bitisset.
SPRUEM1–May2007VideoPort31
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