User`s guide

Rev. 1.10 44 November 14, 2014 Rev. 1.10 45 November 14, 2014
HT66FW2230
Wireless Charger A/D Flash 8-Bit MCU
“CLR WDT”Instruction
8-stage Divider WDT Prescaler
WE4~WE0 bits
WDTC
Register
Reset MCU
f
SUB
f
SUB
/2
8
8-to-1 MUX
CLR
WS2~WS0 WDT Time-out
(2
8
/f
SUB
~ 2
18
/f
SUB
)
“HALT”Instruction
Watchdog Timer
Reset and Initialisation
Aresetfunctionisafundamentalpartofanymicrocontrollerensuringthatthedevicecanbeset
tosomepredeterminedconditionirrespectiveofoutsideparameters.Thereisanumberofother
hardwareandsoftwareresetsourcesthatcanbeimplementeddynamicallywhenthedeviceis
running.
Reset Overview
Themostimportantresetconditionisafterpowerisrstappliedtothemicrocontroller.Inthiscase,
internalcircuitrywillensurethatthemicrocontroller,afterashortdelay,willbeinawelldened
stateandreadytoexecutetherstprograminstruction.Afterthispower-onreset,certainimportant
internalregisterswillbesettodenedstatesbeforetheprogramcommences.Oneoftheseregisters
istheProgramCounter,whichwillberesettozeroforcingthemicrocontrollertobeginprogram
executionfromthelowestProgramMemoryaddress.
Thedeviceprovidesseveralresetsourcestogeneratetheinternalresetsignal,providingextended
MCUprotection.Thedifferenttypesofresetsarelistedintheaccompanyingtable.
Reset Name Abbreviation Indication Bit Register Notes
Power-On Reset POR — — Auto generated at power on
RSTC Register Setting
Software Reset
— ERSTF RSTFC Write to RSTC register
Low-Voltage Reset LVR LRF RSTFC Low V
DD
voltage
Watchdog Reset WDT TO STATUS
WDT Time-out
WDTC Register Setting
Software Reset
— WRF RSTFC Write to WDTC register
MCD Reset — — — Missing Clock Detector
AnothertypeofresetiswhentheWatchdogTimeroverflowsandresetsthemicrocontroller.All
typesofresetoperationsresultindifferentregisterconditionsbeingsetup.Anotherresetexistsin
theformofaLowVoltageResetwhichisimplementedinsituationswherethepowersupplyvoltage
fallsbelowacertainthreshold.