HT66F20 datasheet(225/298 Pages) HOLTEK

225 / 298 page

Rev. 1.90

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HT66F20/HT66F30/HT66F40/HT66F50/HT66F60

HT66FU30/HT66FU40/HT66FU50/HT66FU60

Enhanced A/D Flash Type 8-Bit MCU with EEPROM

HT66F20/HT66F30/HT66F40/HT66F50/HT66F60

HT66FU30/HT66FU40/HT66FU50/HT66FU60

Enhanced A/D Flash Type 8-Bit MCU with EEPROM

LVD Interrupt

TheLowVoltageDetectorInterruptiscontainedwithintheMulti-functionInterrupt.AnLVD

InterruptrequestwilltakeplacewhentheLVDInterruptrequestflag,LVF,isset,whichoccurs

whentheLowVoltageDetectorfunctiondetectsalowpowersupplyvoltage.Toallowtheprogram

tobranchtoitsrespectiveinterruptvectoraddress,theglobalinterruptenablebit,EMI,LowVoltage

Interruptenablebit,LVE,andassociatedMulti-functioninterruptenablebit,mustfirstbeset.When

theinterruptisenabled,thestackisnotfullandalowvoltageconditionoccurs,asubroutinecallto

theMulti-functionInterruptvector,willtakeplace.WhentheLowVoltageInterruptisserviced,the

EMIbitwillbeautomaticallyclearedtodisableotherinterrupts,howeveronlytheMulti-function

interruptrequestflagwillbealsoautomaticallycleared.AstheLVFflagwillnotbeautomatically

cleared,ithastobeclearedbytheapplicationprogram.

TM Interrupts

TheCompactandStandardTypeTMshavetwointerruptseach,whiletheEnhancedTypeTMhas

threeinterrupts.AlloftheTMinterruptsarecontainedwithintheMulti-functionInterrupts.Foreach

oftheCompactandStandardTypeTMstherearetwointerruptrequestflagsTnPFandTnAFand

twoenablebitsTnPEandTnAE.FortheEnhancedTypeTMtherearethreeinterruptrequestflags

TnPF,TnAFandTnBFandthreeenablebitsTnPE,TnAEandTnBE.ATMinterruptrequestwill

takeplacewhenanyoftheTMrequestflagsareset,asituationwhichoccurswhenaTMcomparator

P,AorBmatchsituationhappens.

Toallowtheprogramtobranchtoitsrespectiveinterruptvectoraddress,theglobalinterruptenable

bit,EMI,respectiveTMInterruptenablebit,andrelevantMulti-functionInterruptenablebit,MFnE,

mustfirstbeset.Whentheinterruptisenabled,thestackisnotfullandaTMcomparatormatch

situationoccurs,asubroutinecalltotherelevantMulti-functionInterruptvectorlocations,willtake

place.WhentheTMinterruptisserviced,theEMIbitwillbeautomaticallyclearedtodisableother

interrupts,howeveronlytherelatedMFnFflagwillbeautomaticallycleared.AstheTMinterrupt

requestflagswillnotbeautomaticallycleared,theyhavetobeclearedbytheapplicationprogram.

HT66F20 Datasheet(PDF) 225 Page - Holtek Semiconductor Inc