HT66F60 datasheet(67/298 Pages) HOLTEK

67 / 298 page

Rev. 1.90

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Rev. 1.90

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HT66F20/HT66F30/HT66F40/HT66F50/HT66F60

HT66FU30/HT66FU40/HT66FU50/HT66FU60

Enhanced A/D Flash Type 8-Bit MCU with EEPROM

HT66F20/HT66F30/HT66F40/HT66F50/HT66F60

HT66FU30/HT66FU40/HT66FU50/HT66FU60

Enhanced A/D Flash Type 8-Bit MCU with EEPROM

Entering the IDLE1 Mode

ThereisonlyonewayforthedevicetoentertheIDLE1Modeandthatistoexecutethe“HALT”

instructionintheapplicationprogramwiththeIDLENbitinSMODregisterequalto“1”andthe

FSYSONbitinWDTCregisterequalto“1”.Whenthisinstructionisexecutedunderthewith

conditionsdescribedabove,thefollowingwilloccur:

• ThesystemclockandTimeBaseclockandfSUBclockwillbeonandtheapplicationprogramwill

stopatthe“HALT”instruction.

• TheDataMemorycontentsandregisterswillmaintaintheirpresentcondition.

• TheWDTwillbeclearedandresumecountingiftheWDTisenabledregardlessoftheWDT

clocksourcewhichoriginatesfromthefSUBclockorfromthesystemclock.

• TheI/Oportswillmaintaintheirpresentconditions.

• Inthestatusregister,thePowerDownflag,PDF,willbesetandtheWatchdogtime-outflag,TO,

willbecleared.

Standby Current Considerations

AsthemainreasonforenteringtheSLEEPorIDLEModeistokeepthecurrentconsumptionofthe

devicetoaslowavalueaspossible,perhapsonlyintheorderofseveralmicro-ampsexceptinthe

IDLE1Mode,thereareotherconsiderationswhichmustalsobetakenintoaccountbythecircuit

designerifthepowerconsumptionistobeminimised.SpecialattentionmustbemadetotheI/Opins

onthedevice.Allhigh-impedanceinputpinsmustbeconnectedtoeitherafixedhighorlowlevelas

anyfloatinginputpinscouldcreateinternaloscillationsandresultinincreasedcurrentconsumption.

Thisalsoappliestodeviceswhichhavedifferentpackagetypes,astheremaybeunbonbedpins.

Thesemusteitherbesetupasoutputsorifsetupasinputsmusthavepull-highresistorsconnected.

Caremustalsobetakenwiththeloads,whichareconnectedtoI/Opins,whicharesetupasoutputs.

Theseshouldbeplacedinaconditioninwhichminimumcurrentisdrawnorconnectedonlyto

externalcircuitsthatdonotdrawcurrent,suchasotherCMOSinputs.Alsonotethatadditional

standbycurrentwillalsoberequirediftheconfigurationoptionshaveenabledtheLXTorLIRC

oscillator.

IntheIDLE1Modethesystemoscillatorison,ifthesystemoscillatorisfromthehighspeed

systemoscillator,theadditionalstandbycurrentwillalsobeperhapsintheorderofseveralhundred

micro-amps.

HT66F60 Datasheet(PDF) 67 Page - Holtek Semiconductor Inc