Holtek HT66F30 User Manual

Rev. 2.50 66 June 22, 2017 Rev. 2.50 67 June 22, 2017
HT66F20/HT66F30/HT66F40/HT66F50/HT66F60
HT66FU30/HT66FU40/HT66FU50/HT66FU60
A/D Flash MCU with EEPROM
HT66F20/HT66F30/HT66F40/HT66F50/HT66F60
HT66FU30/HT66FU40/HT66FU50/HT66FU60
A/D Flash MCU with EEPROM
Entering the IDLE1 Mode
ThereisonlyonewayforthedevicetoentertheIDLE1Modeandthatistoexecutethe“HALT”
instructionintheapplicationprogramwiththeIDLENbitinSMODregisterequalto“1”andthe
FSYSONbitinWDTCregisterequalto“1”.Whenthisinstructionisexecutedunderthewith
conditionsdescribedabove,thefollowingwilloccur:
• ThesystemclockandTimeBaseclockandf
SUB
clockwillbeonandtheapplicationprogramwill
stopatthe“HALT”instruction.
• TheDataMemorycontentsandregisterswillmaintaintheirpresentcondition.
• TheWDTwillbeclearedandresumecountingiftheWDTisenabledregardlessoftheWDT
clocksourcewhichoriginatesfromthef
SUB
clockorfromthesystemclock.
• TheI/Oportswillmaintaintheirpresentconditions.
• Inthestatusregister,thePowerDownag,PDF,willbesetandtheWatchdogtime-outag,TO,
willbecleared.
Standby Current Considerations
AsthemainreasonforenteringtheSLEEPorIDLEModeistokeepthecurrentconsumptionofthe
devicetoaslowavalueaspossible,perhapsonlyintheorderofseveralmicro-ampsexceptinthe
IDLE1Mode,thereareotherconsiderationswhichmustalsobetakenintoaccountbythecircuit
designerifthepowerconsumptionistobeminimised.SpecialattentionmustbemadetotheI/Opins
onthedevice.Allhigh-impedanceinputpinsmustbeconnectedtoeitheraxedhighorlowlevelas
anyoatinginputpinscouldcreateinternaloscillationsandresultinincreasedcurrentconsumption.
Thisalsoappliestodeviceswhichhavedifferentpackagetypes,astheremaybeunbonbedpins.
Thesemusteitherbesetupasoutputsorifsetupasinputsmusthavepull-highresistorsconnected.
Caremustalsobetakenwiththeloads,whichareconnectedtoI/Opins,whicharesetupasoutputs.
Theseshouldbeplacedinaconditioninwhichminimumcurrentisdrawnorconnectedonlyto
externalcircuitsthatdonotdrawcurrent,suchasotherCMOSinputs.Alsonotethatadditional
standbycurrentwillalsoberequiredifthecongurationoptionshaveenabledtheLXTorLIRC
oscillator.
IntheIDLE1Modethesystemoscillatorison,ifthesystemoscillatorisfromthehighspeed
systemoscillator,theadditionalstandbycurrentwillalsobeperhapsintheorderofseveralhundred
micro-amps.

Holtek HT66F30 Specifications

General

Brand	Holtek
Model	HT66F30
Category	Computer Hardware
Language	English