Holtek HT66F30 - System Operation Modes

Rev. 2.50 58 June 22, 2017 Rev. 2.50 59 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
System Operation Modes
Therearesixdifferentmodesofoperationforthemicrocontroller,eachonewithitsown
specialcharacteristicsandwhichcanbechosenaccordingtothespecificperformanceand
powerrequirementsoftheapplication.Therearetwomodesallowingnormaloperationofthe
microcontroller,theNORMALModeandSLOWMode.Theremainingfourmodes,theSLEEP0,
SLEEP1,IDLE0andIDLE1ModeareusedwhenthemicrocontrollerCPUisswitchedoffto
conservepower.
Operating Mode
Description
CPU f
SYS
f
SUB
f
S
f
TBC
NORMAL Mode On f
H
~f
H
/64 On On On
SLOW Mode On f
L
On On On
IDLE0 Mode Off Off On On/Off On
IDLE1 Mode Off On On On On
SLEEP0 Mode Off Off Off Off Off
SLEEP1 Mode Off Off On On Off
• NORMALMode
Asthenamesuggeststhisisoneofthemainoperatingmodeswherethemicrocontrollerhas
allofitsfunctionsoperationalandwherethesystemclockisprovidedbyoneofthehigh
speedoscillators.Thismodeoperatesallowingthemicrocontrollertooperatenormallywitha
clocksourcewillcomefromoneofthehighspeedoscillators,eithertheHXT,ERCorHIRC
oscillators.Thehighspeedoscillatorwillhoweverrstbedividedbyaratiorangingfrom1to
64,theactualratiobeingselectedbytheCKS2~CKS0andHLCLKbitsintheSMODregister.
Althoughahighspeedoscillatorisused,runningthemicrocontrolleratadividedclockratio
reducestheoperatingcurrent.
• SLOWMode
Thisisalsoamodewherethemicrocontrolleroperatesnormallyalthoughnowwithaslower
speedclocksource.Theclocksourceusedwillbefromoneofthelowspeedoscillators,either
theLXTortheLIRC.Runningthemicrocontrollerinthismodeallowsittorunwithmuchlower
operatingcurrents.IntheSLOWMode,thef
H
isoff.
• SLEEP0Mode
TheSLEEPModeisenteredwhenanHALTinstructionisexecutedandwhentheIDLENbit
intheSMODregisterislow.IntheSLEEP0modetheCPUwillbestopped,andthef
SUB
and
f
S
clockswillbestoppedtoo,andtheWatchdogTimerfunctionisdisabled.Inthismode,the
LVDENismustsetto0.IftheLVDENissetto"1",itwontentertheSLEEP0Mode.
• SLEEP1Mode
TheSLEEPModeisenteredwhenanHALTinstructionisexecutedandwhentheIDLENbitin
theSMODregisterislow.IntheSLEEP1modetheCPUwillbestopped.Howeverthef
SUB
and
f
S
clockswillcontinuetooperateiftheLVDENis"1"ortheWatchdogTimerfunctionisenabled
andifitsclocksourceischosenviacongurationoptiontocomefromthef
SUB
.