HT66F20 datasheet(222/298 Pages) HOLTEK

222 / 298 page

Rev. 1.90

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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

A/D Converter Interrupt

TheA/DConverterInterruptiscontrolledbytheterminationofanA/Dconversionprocess.AnA/D

ConverterInterruptrequestwilltakeplacewhentheA/DConverterInterruptrequestflag,ADF,is

set,whichoccurswhentheA/Dconversionprocessfinishes.Toallowtheprogramtobranchtoits

respectiveinterruptvectoraddress,theglobalinterruptenablebit,EMI,andA/DInterruptenablebit,

ADE,mustfirstbeset.Whentheinterruptisenabled,thestackisnotfullandtheA/Dconversion

processhasended,asubroutinecalltotheA/DConverterInterruptvector,willtakeplace.Whenthe

interruptisserviced,theA/DConverterInterruptflag,ADF,willbeautomaticallycleared.TheEMI

bitwillalsobeautomaticallyclearedtodisableotherinterrupts.

Time Base Interrupt

ThefunctionoftheTimeBaseInterruptsistoprovideregulartimesignalintheformofaninternal

interrupt.Theyarecontrolledbytheoverflowsignalsfromtheirrespectivetimerfunctions.When

thesehappenstheirrespectiveinterruptrequestflags,TB0ForTB1Fwillbeset.Toallowthe

programtobranchtotheirrespectiveinterruptvectoraddresses,theglobalinterruptenablebit,EMI

andTimeBaseenablebits,TB0EorTB1E,mustfirstbeset.Whentheinterruptisenabled,thestack

isnotfullandtheTimeBaseoverflows,asubroutinecalltotheirrespectivevectorlocationswill

takeplace.Whentheinterruptisserviced,therespectiveinterruptrequestflag,TB0ForTB1F,will

beautomaticallyresetandtheEMIbitwillbeclearedtodisableotherinterrupts.

ThepurposeoftheTimeBaseInterruptistoprovideaninterruptsignalatfixedtimeperiods.Their

clocksourcesoriginatefromtheinternalclocksourcefTB.ThisfTBinputclockpassesthrougha

divider,thedivisionratioofwhichisselectedbyprogrammingtheappropriatebitsintheTBC

registertoobtainlongerinterruptperiodswhosevalueranges.TheclocksourcethatgeneratesfTB,

whichinturncontrolstheTimeBaseinterruptperiod,canoriginatefromseveraldifferentsources,

asshownintheSystemOperatingModesection.

HT66F20 Datasheet(PDF) 222 Page - Holtek Semiconductor Inc