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PRODUCT PREVIEW
TMS320DM355
DigitalMediaSystem-on-Chip(DMSoC)
SPRS463A–SEPTEMBER2007–REVISEDSEPTEMBER2007
5.9.1.3Hardware3A(H3A)
TheH3AmoduleisdesignedtosupportthecontrolloopsforAutoFocus,AutoWhiteBalanceandAuto
Exposurebycollectingmetricsabouttheimaging/videodata.Themetricsaretoadjustthevarious
parametersforprocessingtheimaging/videodata.Thereare2mainblocksintheH3Amodule:
•AutoFocus(AF)engine
•AutoExposure(AE)AutoWhiteBalance(AWB)engine
TheAFengineextractsandfiltersthered,green,andbluedatafromtheinputimage/videodataand
provideseithertheaccumulationorpeaksofthedatainaspecifiedregion.Thespecifiedregionisa
two-dimensionalblockofdataandisreferredtoasa"paxel"forthecaseofAF.
TheAE/AWBEngineaccumulatesthevaluesandchecksforsaturatedvaluesinasubsamplingofthe
videodata.InthecaseoftheAE/AWB,thetwo-dimensionalblockofdataisreferredtoasa"window".
Thus,otherthanreferringthembydifferentnames,apaxelandawindowareessentiallythesamething.
However,thenumber,dimensions,andstartingpositionoftheAFpaxelsandtheAE/AWBwindowsare
separatelyprogrammable.
ThefollowingfeaturesaresupportedbytheAFengine:
•SupportforinputfromDDR2/mDDRSDRAM(inadditiontotheCCDCport)
•SupportforaPeakModeinaPaxel(aPaxelisdefinedasatwodimensionalblockofpixels).
•AccumulatethemaximumFocusValueofeachlineinaPaxel
•SupportforanAccumulation/SumMode(insteadofPeakmode).
•AccumulateFocusValueinaPaxel.
•Supportforupto36Paxelsinthehorizontaldirectionandupto128Paxelsintheverticaldirection.
Thenumberofhorizontalpaxelsislimitedbythememorysize(andcost),whiletheverticalnumberof
paxelsisnot.Therefore,thenumberofpaxelsinhorizontaldirectionissmallerthanthenumberof
paxelsinverticaldirection.
•ProgrammablewidthandheightforthePaxel.Allpaxelsintheframewillbeofsamesize.
•Programmablered,green,andbluepositionwithina2x2matrix.
•Separatehorizontalstartforpaxelandfiltering.
•Programmableverticallineincrementswithinapaxel.
•ParallelIIRfiltersconfiguredinadual-biquadconfigurationwithindividualcoefficients(2filterswith11
coefficientseach).Thefiltersareintendedtocomputethesharpness/peaksintheframetofocuson.
ThefollowingfeaturesaresupportedbytheAE/AWBengine:
•SupportforinputfromDDR2/mDDRSDRAM(inadditiontotheCCDCport)
•Accumulateclippedpixelsalongwithallnon-saturatedpixels
•Supportforupto36horizontalwindows.
•Supportforupto128verticalwindows.
•Programmablewidthandheightforthewindows.Allwindowsintheframewillbeofsamesize.
•Separateverticalstartco-ordinateandheightforablackrowofpaxelsthatisdifferentthanthe
remainingcolorpaxels.
•ProgrammableHorizontalSamplingPointsinawindow
•ProgrammableVerticalSamplingPointsinawindow
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