HT45FH4M
Lithium Battery Backup Power ASSP MCU
In Circuit Programming
TheꢀprovisionꢀofꢀFlashꢀtypeꢀProgramꢀMemoryꢀprovidesꢀtheꢀuserꢀwithꢀaꢀmeansꢀofꢀconvenientꢀandꢀeasyꢀ
upgradesꢀandꢀmodificationsꢀtoꢀtheirꢀprogramsꢀonꢀtheꢀsameꢀdevice.ꢀAsꢀanꢀadditionalꢀconvenience,ꢀ
Holtekꢀhasꢀprovidedꢀaꢀmeansꢀofꢀprogrammingꢀtheꢀmicrocontrollerꢀin-circuitꢀusingꢀaꢀ4-pinꢀinterface.ꢀ
Thisꢀprovidesꢀmanufacturersꢀwithꢀtheꢀpossibilityꢀofꢀmanufacturingꢀtheirꢀcircuitꢀboardsꢀcompleteꢀwithꢀ
aꢀprogrammedꢀorꢀun-programmedꢀmicrocontroller,ꢀandꢀthenꢀprogrammingꢀorꢀupgradingꢀtheꢀprogramꢀ
atꢀaꢀlaterꢀstage.ꢀThisꢀenablesꢀproductꢀmanufacturersꢀtoꢀeasilyꢀkeepꢀtheirꢀmanufacturedꢀproductsꢀ
suppliedꢀwithꢀtheꢀlatestꢀprogramꢀreleasesꢀwithoutꢀremovalꢀandꢀre-insertionꢀofꢀtheꢀdevice.
TheꢀHoltekꢀFlashꢀMCUꢀtoꢀWriterꢀProgrammingꢀPinꢀcorrespondenceꢀtableꢀisꢀasꢀfollows:
Holtek Writer Pins
MCU Programming Pins
Pin Description
Pꢁogꢁamming Seꢁial Data/Addꢁess
Pꢁogꢁamming Clock
Poweꢁ Sꢀpplꢂ
ICPDA
ICPCK
VDD
PA6
PA7
VDD
VSS
VSS
Gꢁoꢀnd
Duringꢀtheꢀprogrammingꢀprocess,ꢀtheꢀuserꢀmustꢀthereꢀtakeꢀcareꢀtoꢀensureꢀthatꢀnoꢀotherꢀoutputsꢀareꢀ
connectedꢀtoꢀtheseꢀtwoꢀpins.
TheꢀProgramꢀMemoryꢀandꢀEEPROMꢀdataꢀmemoryꢀcanꢀbothꢀbeꢀprogrammedꢀseriallyꢀin-circuitꢀusingꢀ
thisꢀ4-wireꢀinterface.ꢀDataꢀisꢀdownloadedꢀandꢀuploadedꢀseriallyꢀonꢀaꢀsingleꢀpinꢀwithꢀanꢀadditionalꢀ
lineꢀforꢀtheꢀclock.ꢀTwoꢀadditionalꢀlinesꢀareꢀrequiredꢀforꢀtheꢀpowerꢀsupply.ꢀTheꢀtechnicalꢀdetailsꢀ
regardingꢀtheꢀin-circuitꢀprogrammingꢀofꢀtheꢀdeviceꢀareꢀbeyondꢀtheꢀscopeꢀofꢀthisꢀdocumentꢀandꢀwillꢀ
beꢀsuppliedꢀinꢀsupplementaryꢀliterature.
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Note:ꢀ*ꢀmayꢀbeꢀresistorꢀorꢀcapacitor.ꢀTheꢀresistanceꢀofꢀ*ꢀmustꢀbeꢀgreaterꢀthanꢀ1kꢀorꢀtheꢀcapacitanceꢀ
ofꢀ*ꢀmustꢀbeꢀlessꢀthanꢀ1nF.
Rev. 1.10
ꢅ0
�anꢀaꢁꢂ 1ꢃꢄ ꢅ01ꢆ
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
