User`s guide

Rev. 1.10 40 November 14, 2014 Rev. 1.10 41 November 14, 2014
HT66FW2230
Wireless Charger A/D Flash 8-Bit MCU
Entering the IDLE2 Mode
ThereisonlyonewayforthedevicetoentertheIDLE2Modeandthatistoexecutethe“HALT”
instructionintheapplicationprogramwiththeFHIDENbitintheSCCregisterequalto“1”andthe
FLIDENbitinSCCregisterequalto“0”.Whenthisinstructionisexecutedundertheconditions
describedabove,thefollowingwilloccur:
• Thef
H
clockwillbeonbutthef
SUB
clockwillbeoffandtheapplicationprogramwillstopatthe
“HALT”instruction.
• TheDataMemorycontentsandregisterswillmaintaintheirpresentcondition.
• TheI/Oportsofperipheraldevicewillkeeptoworkwhenitisenabledandclockisfromf
SYS
.
•
Inthestatusregister,thePowerDownagPDFwillbeset,andWDTtimeoutagTOwillbe
cleared.
•
TheWDTwillbeclearedandresumecounting.
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andIDLE2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LIRCoscillatorhasenabled.
IntheIDLE1andIDLE2Modethehighspeedoscillatorison,ifthesystemoscillatorisfromthe
highspeedoscillator,theadditionalstandbycurrentwillalsobeperhapsintheorderofseveral
hundredmicro-amps.