HT45F4MA datasheet(36/145 Pages) HOLTEK

36 / 145 page

Rev. 1.20

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HT45F4MA/HT45FH4MA/HT45FH4MA-1

Power Bank Flash MCU

HT45F4MA/HT45FH4MA/HT45FH4MA-1

Power Bank Flash MCU

Internal RC Oscillator – HIRC

TheinternalRCoscillatorisafullyintegratedsystemoscillatorrequiringnoexternalcomponents.

TheinternalRCoscillatorhasseveralfrequenciesofeither30MHzbyoption.Devicetrimming

duringthemanufacturingprocessandtheinclusionofinternalfrequencycompensationcircuitsare

usedtoensurethattheinfluenceofthepowersupplyvoltage,temperatureandprocessvariationson

theoscillationfrequencyareminimised.Notethatifthisinternalsystemclockoptionisselected,as

itrequiresnoexternalpinsforitsoperation.

Internal 32kHz Oscillator – LIRC

TheInternal32kHzSystemOscillatoristhelowfrequencyoscillator.Itisafullyintegrated

RCoscillatorwithatypicalfrequencyof32kHzat5V,requiringnoexternalcomponentsforits

implementation.Devicetrimmingduringthemanufacturingprocessandtheinclusionofinternal

frequencycompensationcircuitsareusedtoensurethattheinfluenceofthepowersupplyvoltage,

temperatureandprocessvariationsontheoscillationfrequencyareminimised.

Operating Modes and System Clocks

Presentdayapplicationsrequirethattheirmicrocontrollershavehighperformancebutoftenstill

demandthattheyconsumeaslittlepoweraspossible,conflictingrequirementsthatareespecially

trueinbatterypoweredportableapplications.Thefastclocksrequiredforhighperformancewill

bytheirnatureincreasecurrentconsumptionandofcoursevice-versa,lowerspeedclocksreduce

currentconsumption.AsHoltekhasprovidedthisdevicewithbothhighandlowspeedclock

sourcesandthemeanstoswitchbetweenthemdynamically,theusercanoptimisetheoperationof

theirmicrocontrollertoachievethebestperformance/powerratio.

System Clocks

ThedevicehasmanydifferentclocksourcesforboththeCPUandperipheralfunctionoperation.

Byprovidingtheuserwithawiderangeofclockoptionsusingconfigurationoptionsandregister

programming,aclocksystemcanbeconfiguredtoobtainmaximumapplicationperformance.

Themainsystemclock,cancomefromeitherahighfrequency,fH,orlowfrequency,fSUB,source,

andisselectedusingtheHLCLKbitandCKS2~CKS0bitsintheSMODregister.Thehighspeed

systemclockcanbesourcedfromtheHIRCoscillator.Thelowspeedsystemclocksourcecanbe

sourcedfromtheLIRCoscillator.Theotherchoice,whichisadividedversionofthehighspeed

systemoscillatorhasarangeoffH/2~fH/64.

HT45F4MA 데이터시트(PDF) 36 Page - Holtek Semiconductor Inc