HT69F360 datasheet(205/235 Pages) HOLTEK

205 / 235 page

Rev. 1.30

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HT69F340/HT69F350/HT69F360

TinyPowerTM I/O Flash MCU with LCD & EEPROM

HT69F340/HT69F350/HT69F360

TinyPowerTM I/O Flash MCU with LCD & EEPROM

Programming Considerations

CertainprecautionsmustbetakenwhenprogrammingtheLCD.Oneoftheseistoensurethatthe

LCDMemory isproperlyinitializedafterthemicrocontrollerispoweredon.LiketheGeneral

PurposeDataMemory,thecontentsoftheLCDMemoryareinanunknownconditionafterpower-on.

AsthecontentsoftheLCDMemorywillbemappedintotheactualdisplay,itisimportantto

initilisethismemoryareaintoaknownconditionsoonafterapplyingpowertoobtainaproper

displaypattern.

ConsiderationmustalsobegiventothecapacitiveloadoftheactualLCDusedintheapplication.

AstheloadpresentedtothemicrocontrollerbyLCDpixelscanbegenerallymodeledasmainly

capacitiveinnature,itisimportantthatthisisnotexcessive,apointthatisparticularlytrueinthe

caseoftheCOMlineswhichmaybeconnectedtomanyLCDpixels.Theaccompanyingdiagram

depictstheequivalentcircuitoftheLCD.

One additional consideration that must be taken into account is what happens when the

microcontrollerenterstheIdleorSlowMode.TheLCDENcontrolbitintheLCDC0register

permitsthedisplaytobepoweredofftoreducepowerconsumption.Ifthisbitiszero,thedriving

signalstothedisplaywillcease,producingablankdisplaypatternbutreducinganypower

consumptionassociatedwiththeLCD.

Afterpoweron,notethatastheLCDENbitwillbeclearedtozero,thedisplayfunctionwillbe

disabled.

CO M0

CO M1

CO M2

CO Mn

SE G0

SEG 1S EG 2

SEG n

LCD Panel Equivalent Circuit

HT69F360 데이터시트(PDF) 205 Page - Holtek Semiconductor Inc