HT69F240 datasheet(90/172 Pages) HOLTEK

90 / 172 page

Rev. 1.20

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Rev. 1.20

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HT69F240

I/O 8-Bit Flash MCU with LED/LCD Driver

HT69F240

I/O 8-Bit Flash MCU with LED/LCD Driver

Capture Input Mode

ToselectthismodebitsPTM1andPTM0inthePTMC1registershouldbesetto01respectively.This

modeenablesexternalsignalstocaptureandstorethepresentvalueoftheinternalcounterandcan

thereforebeusedforapplicationssuchaspulsewidthmeasurements.Theexternalsignalissuppliedon

thePTPIorPTCKpin,selectedbythePTCAPTSbitinthePTMC0register.Thecaptureinputpinactive

edgecanbeeitherarisingedge,afallingedgeorbothrisingandfallingedges;theactiveedgetransition

typeisselectedusingthePTIO1andPTIO0bitsinthePTMC1register.Thecounterisstartedwhenthe

PTONbitchangesfromlowtohighwhichisinitiatedusingtheapplicationprogram.

WhentherequirededgetransitionappearsonthePTPIorPTCKpinthepresentvalueinthecounterwill

belatchedintotheCCRAregistersandaTMinterruptgenerated.Irrespectiveofwhateventsoccuron

thePTPIorPTCKpinthecounterwillcontinuetofreerununtilthePTONbitchangesfromhightolow.

WhenaCCRPcomparematchoccursthecounterwillresetbacktozero;inthiswaytheCCRPvaluecan

beusedtocontrolthemaximumcountervalue.WhenaCCRPcomparematchoccursfromComparatorP,

aTMinterruptwillalsobegenerated.CountingthenumberofoverflowinterruptsignalsfromtheCCRP

canbeausefulmethodinmeasuringlongpulsewidths.ThePTIO1andPTIO0bitscanselecttheactive

triggeredgeonthePTPIorPTCKpintobearisingedge,fallingedgeorbothedgetypes.IfthePTIO1

andPTIO0bitsarebothsethigh,thennocaptureoperationwilltakeplaceirrespectiveofwhathappens

onthePTPIorPTCKpin,howeveritmustbenotedthatthecounterwillcontinuetorun.

AsthePTPIorPTCKpinispinsharedwithotherfunctions,caremustbetakeniftheTMisinthe

CaptureInputMode.Thisisbecauseifthepinissetupasanoutput,thenanytransitionsonthispinmay

causeaninputcaptureoperationtobeexecuted.ThePTCCLR,PTOCandPTPOLbitsarenotusedin

thisMode.

HT69F240 Datasheet(PDF) 90 Page - Holtek Semiconductor Inc