HT67F488 datasheet(26/171 Pages) HOLTEK

26 / 171 page

Rev. 1.60

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HT67F488/HT67F489

TinyPowerTM A/D Flash MCU with LCD & EEPROM

Data Memory Addressing

Forthedevicesthatsupporttheextendedinstructions,thereisnoBankPointerforDataMemory

addressing.ForDataMemorythedesiredSectorispointedbytheMP1HorMP2Hregisterandthe

certainDataMemoryaddressintheselectedsectorisspecifiedbytheMP1LorMP2Lregisterwhen

usingindirectaddressingaccess.

DirectAddressingcanbeusedinallsectorsusingthecorrespondinginstructionwhichcanaddress

allavailabledatamemoryspace.Fortheaccesseddatamemorywhichislocatedinanydatamemory

sectorsexceptsector0,theextendedinstructionscanbeusedtoaccessthedatamemoryinstead

ofusingtheindirectaddressingaccess.Themaindifferencebetweenstandardinstructionsand

extendedinstructionsisthatthedatamemoryaddress“m”intheextendedinstructionshas10valid

bits,thehighbyteindicatesasectorandthelowbyteindicatesaspecificaddress.

General Purpose Data Memory

Thereare256bytesofgeneralpurposememorywhicharearrangedin80H~FFHofSector0,

Sector2separately.Andanother20bytesofLCDmemoryaremappedin80H~93HofSector1.All

microcontrollerprogramsrequireanareaofread/writememorywheretemporarydatacanbestored

andretrievedforuselater.ItisthisareaofRAMmemorythatisknownasGeneralPurposeData

Memory.Thegeneralpurposedatamemoryisfullyaccessiblebytheuserprogramforbothreadand

writingoperations.Byusingthe"SET[m].i"and"CLR[m].i"instructionsindividualbitscanbeset

orresetunderprogramcontrolgivingtheuseralargerangeofflexibilityforbitmanipulationinthe

DataMemory.

Special Purpose Data Memory

This area of Data Memory is where registers, necessary for the correct operation of the

microcontroller,arestored.Theyareoverlappedinanysector.Mostoftheregistersareboth

readableandwritablebutsomeareprotectedandarereadableonly,thedetailsofwhicharelocated

undertherelevantSpecialFunctionRegistersection.Notethatforlocationsthatareunusedbefore

80H,anyreadinstructiontotheseaddresseswillreturnthevalue"00H".

HT67F488 Datasheet(PDF) 26 Page - Holtek Semiconductor Inc