User`s guide

Rev. 1.10 24 November 14, 2014 Rev. 1.10 25 November 14, 2014
HT66FW2230
Wireless Charger A/D Flash 8-Bit MCU
Accumulator – ACC
TheAccumulatoriscentraltotheoperationofanymicrocontroller andiscloselyrelatedwith
operationscarriedoutbytheALU.TheAccumulatoristheplacewhereallintermediateresults
fromtheALUarestored.WithouttheAccumulatoritwouldbenecessarytowritetheresultof
eachcalculationorlogicaloperationsuchasaddition,subtraction,shift,etc.,totheDataMemory
resultinginhigherprogrammingandtimingoverheads.Datatransferoperationsusuallyinvolve
thetemporarystoragefunctionoftheAccumulator;forexample,whentransferringdatabetween
oneuser-definedregisterandanother,itisnecessarytodothisbypassingthedatathroughthe
Accumulatorasnodirecttransferbetweentworegistersispermitted.
Program Counter Low Register – PCL
Toprovideadditionalprogramcontrolfunctions,thelowbyteoftheProgramCounterismade
accessibletoprogrammersbylocatingitwithintheSpecialPurposeareaoftheDataMemory.By
manipulatingthisregister,directjumpstootherprogramlocationsareeasilyimplemented.Loading
avaluedirectlyintothisPCLregisterwillcauseajumptothespeciedProgramMemorylocation,
however,astheregisterisonly8-bitwide,onlyjumpswithinthecurrentProgramMemorypageare
permitted.Whensuchoperationsareused,notethatadummycyclewillbeinserted.
Look-up Table Registers – TBLP, TBHP, TBLH
Thesethreespecialfunctionregistersareusedtocontroloperationofthelook-uptablewhichis
storedintheProgramMemory.TBLPandTBHParethetablepointersandindicatethelocation
wherethetabledataislocated.Theirvaluemustbesetupbeforeanytablereadcommandsare
executed.Theirvaluecanbechanged,forexampleusingthe“INC”or“DEC”instructions,allowing
foreasytabledatapointingandreading.TBLHisthelocationwherethehighorderbyteofthetable
dataisstoredafteratablereaddatainstructionhasbeenexecuted.Notethatthelowerordertable
databyteistransferredtoauserdenedlocation.
Status Register – STATUS
This8-bitregistercontainstheSC,CZ,zeroflag(Z),carryflag(C),auxiliarycarryflag(AC),
overowag(OV),powerdownag(PDF),andwatchdogtime-outag(TO).Thesearithmetic/
logicaloperationandsystemmanagementagsareusedtorecordthestatusandoperationofthe
microcontroller.
WiththeexceptionoftheTOandPDFags,bitsinthestatusregistercanbealteredbyinstructions
likemostotherregisters.AnydatawrittenintothestatusregisterwillnotchangetheTOorPDFag.
Inaddition,operationsrelatedtothestatusregistermaygivedifferentresultsduetothedifferent
instructionoperations.TheTOagcanbeaffectedonlybyasystempower-up,aWDTtime-outor
byexecutingthe“CLRWDT”or“HALT”instruction.ThePDFagisaffectedonlybyexecuting
the“HALT”or“CLRWDT”instructionorduringasystempower-up.
TheSC,CZ,Z,OV,ACandCagsgenerallyreectthestatusofthelatestoperations.
• Cissetifanoperationresultsinacarryduringanadditionoperationorifaborrowdoesnottake
placeduringasubtractionoperation;otherwiseCiscleared.Cisalsoaffectedbyarotatethrough
carryinstruction.
• ACissetifanoperationresultsinacarryoutofthelownibblesinaddition,ornoborrowfrom
thehighnibbleintothelownibbleinsubtraction;otherwiseACiscleared.
• Zissetiftheresultofanarithmeticorlogicaloperationiszero;otherwiseZiscleared.
• OVissetifanoperationresultsinacarryintothehighest-orderbitbutnotacarryoutofthe
highest-orderbit,orviceversa;otherwiseOViscleared.