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
Wake-up
TominimisepowerconsumptionthedevicecanentertheSLEEPoranyIDLEMode,wherethe
CPUwillbeswitchedoff.Howeverwhenthedeviceiswokenupagain,itcantakeaconsiderable
timefortheoriginalsystemoscillatortorestart,stabiliseandallownormaloperationtoresume.
System
Oscillator
Wake-up Time
SLEEP Mode IDLE 0 Mode IDLE 1 Mode IDLE 2 Mode
HXT
1024 HXT cycles 1024 HXT cycles 1~2 HXT cycles 1~2 HXT cycles
HIRC 15~16 HIRC cycles 15~16 HIRC cycles 1~2 HIRC cycles 1~2 HIRC cycles
LIRC 1~2 LIRC cycles 1~2 LIRC cycles 1~2 LIRC cycles 1~2 LIRC cycles
AfterthesystementerstheSLEEPorIDLEMode,itcanbewokenupfromoneofvarioussources
listedasfollows:
• AnexternalfallingedgeonPortA
• Asysteminterrupt
• AWDToverow
IfthedeviceiswokenupbyaWDToverow,aWatchdogTimerresetwillbeinitiated.Although
bothofthesewake-upmethodswillinitiatearesetoperation,theactualsourceofthewake-upcan
bedeterminedbyexaminingtheTOandPDFags.ThePDFagisclearedbyasystempower-upor
executingtheclearWatchdogTimerinstructionsandissetwhenexecutingthe"HALT"instruction.
TheTOagissetifaWDTtime-outoccurs,andcausesawake-upthatonlyresetstheProgram
CounterandStackPointer,theotheragsremainintheiroriginalstatus.
EachpinonPortAcanbesetupusingthePAWUregistertopermitanegativetransitiononthepin
towake-upthesystem.WhenaPortApinwake-upoccurs,theprogramwillresumeexecutionat
theinstructionfollowingthe"HALT"instruction.Ifthesystemiswokenupbyaninterrupt,then
twopossiblesituationsmayoccur.Therstiswheretherelatedinterruptisdisabledortheinterrupt
isenabledbutthestackisfull,inwhichcasetheprogramwillresumeexecutionattheinstruction
followingthe"HALT"instruction.Inthissituation,theinterruptwhichwoke-upthedevicewillnot
beimmediatelyserviced,butwillratherbeservicedlaterwhentherelatedinterruptisnallyenabled
orwhenastacklevelbecomesfree.Theothersituationiswheretherelatedinterruptisenabledand
thestackisnotfull,inwhichcasetheregularinterruptresponsetakesplace.Ifaninterruptrequest
flagissethighbeforeenteringtheSLEEPorIDLEMode,thewake-upfunctionoftherelated
interruptwillbedisabled.
Programming Considerations
TheHXT,HIRCandLIRCoscillatorsusedifferentSSTcounter.Forexample,ifthesystemis
wokenupfromtheSLEEPModeandtheHXToscillatorneedstostart-upfromanoffstate.
• IfthedeviceiswokenupfromtheSLEEPModetotheNORMALMode,thehighspeedsystem
oscillatorneedsanSSTperiod.ThedevicewillexecuterstinstructionafterHIRCF/HXTFis
"1".Thesamesituationoccursinthepower-onstate.
• Thereareperipheralfunctions,suchasTMs,forwhichthef
SYS
isused.Ifthesystemclocksource
isswitchedfromf
H
tof
SUB
,theclocksourcetotheperipheralfunctionsmentionedabovewill
changeaccordingly.