Holtek HT66F004 User Manual

Rev. 1.71 42 April 11, 2017 Rev. 1.71 43 April 11, 2017
HT66F002/HT66F0025/HT66F003/HT66F004
Cost-Effective A/D Flash MCU with EEPROM
HT66F002/HT66F0025/HT66F003/HT66F004
Cost-Effective A/D Flash MCU with EEPROM
Bit0 WRF:WDTControlregistersoftwareresetag
0:Notoccur
1:Occurred
Thisbitissetto1bytheWDTControlregistersoftwareresetandclearedby theapplication
program.Notethatthisbitcanonlybeclearedto0bytheapplicationprogram.
Operating Mode Switching
Thedevicescanswitchbetweenoperatingmodesdynamicallyallowingtheusertoselectthebest
performance/powerratioforthepresenttaskinhand.Inthiswaymicrocontrolleroperationsthat
donotrequirehighperformancecanbeexecutedusingslowerclocksthusrequiringlessoperating
currentandprolongingbatterylifeinportableapplications.
Insimpleterms,ModeSwitchingbetweentheNORMALModeandSLOWModeisexecuted
usingtheHLCLKbitandCKS2~CKS0bitsintheSMODregisterwhileModeSwitchingfromthe
NORMAL/SLOWModestotheSLEEP/IDLEModesisexecutedviatheHALTinstruction.When
aHALTinstructionisexecuted,whetherthedeviceenterstheIDLEModeortheSLEEPModeis
determinedbytheconditionoftheIDLENbitintheSMODregisterandFSYSONintheSMOD1
register.
WhentheHLCLKbitswitchestoalowlevel,whichimpliesthatclocksourceisswitchedfromthe
highspeedclocksource,f
H
,totheclocksource,f
H
/2~f
H
/64orf
L
.Iftheclockisfromthef
L
,thehigh
speedclocksourcewillstoprunningtoconservepower.Whenthishappensitmustbenotedthatthe
f
H
/16andf
H
/64internalclocksourceswillalsostoprunning,whichmayaffecttheoperationofother
internalfunctionssuchastheTMs.
 
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Holtek HT66F004 Specifications

General

Brand	Holtek
Model	HT66F004
Category	Control Unit
Language	English