HT45F2020 datasheet(26/85 Pages) HOLTEK

26 / 85 page

Rev. 1.00

April 11, 2017

Rev. 1.00

April 11, 2017

HT45F2020/HT45F2022

Sound Effect Generator Flash MCU

HT45F2020/HT45F2022

Sound Effect Generator Flash MCU

NORMAL Mode

Asthenamesuggeststhisisoneofthemainoperatingmodeswherethemicrocontrollerhasallof

itsfunctionsoperationalandwherethesystemclockisprovidedbythehighspeedoscillators.This

modeoperatesallowingthemicrocontrollertooperatenormallywithaclocksourcewillcomefrom

thehighspeedoscillatorsHIRC.Thehighspeedoscillatorwillhoweverfirstbedividedbyaratio

rangingfrom1to64,theactualratiobeingselectedbytheCKS2~CKS0bitsintheSCCregister.

Althoughahighspeedoscillatorisused,runningthemicrocontrolleratadividedclockratioreduces

theoperatingcurrent.

SLOW Mode

Thisisalsoamodewherethemicrocontrolleroperatesnormallyalthoughnowwithaslowerspeed

clocksource.TheclocksourceusedwillbefromfSUB.ThefSUBclockisderivedfromtheLIRC

oscillator.Runningthemicrocontrollerinthismodeallowsittorunwithmuchloweroperating

currents.

SLEEP Mode

TheSLEEPModeisenteredwhenanHALTinstructionisexecutedandwhentheFHIDENand

FSIDENbitarelow.IntheSLEEPmodetheCPUwillbestopped,andthefSUBclocktoperipheral

willbestoppedtoo,buttheWatchdogTimerfunctionisdecidedbyuserapplication.

IDLE0 Mode

TheIDLE0ModeisenteredwhenanHALTinstructionisexecutedandwhentheFHIDENbitin

theSCCregisterislowandtheFSIDENbitintheSCCregisterishigh.IntheIDLE0Modethe

CPUwillbeswitchedoffbutthelowspeedoscillatorwillbeturnedontodrivesomeperipheral

functions.

IDLE1 Mode

TheIDLE1ModeisenteredwhenanHALTinstructionisexecutedandwhentheFHIDENbitinthe

SCCregisterishighandtheFSIDENbitintheSCCregisterishigh.IntheIDLE1ModetheCPU

willbeswitchedoffbutboththehighandlowspeedoscillatorswillbeturnedontoprovideaclock

sourcetokeepsomeperipheralfunctionsoperational.

IDLE2 Mode

TheIDLE2ModeisenteredwhenanHALTinstructionisexecutedandwhentheFHIDENbitinthe

SCCregisterishighandtheFSIDENbitintheSCCregisterislow.IntheIDLE2ModetheCPU

willbeswitchedoffbutthehighspeedoscillatorwillbeturnedontoprovideaclocksourcetokeep

someperipheralfunctionsoperational.

HT45F2020 Datasheet(PDF) 26 Page - Holtek Semiconductor Inc