HT45F2020 datasheet(65/85 Pages) HOLTEK

65 / 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

Itisrecommendedthatprogramsdonotusethe“CALL”instructionwithintheinterruptservice

subroutine.Interruptsoftenoccurinanunpredictablemannerorneedtobeservicedimmediately.

Ifonlyonestackisleftandtheinterruptisnotwellcontrolled,theoriginalcontrolsequencewillbe

damagedonceaCALLsubroutineisexecutedintheinterruptsubroutine.

EveryinterrupthasthecapabilityofwakingupthemicrocontrollerwhenitisinSLEEPorIDLE

Mode,thewakeupbeinggeneratedwhentheinterruptrequestflagchangesfromlowtohigh.Ifitis

requiredtopreventacertaininterruptfromwakingupthemicrocontrollerthenitsrespectiverequest

flagshouldbefirstsethighbeforeenterSLEEPorIDLEMode.

AsonlytheProgramCounterispushedontothestack,thenwhentheinterruptisserviced,ifthe

contentsoftheaccumulator,statusregisterorotherregistersarealteredbytheinterruptservice

program,theircontentsshouldbesavedtothememoryatthebeginningoftheinterruptservice

routine.

Toreturnfromaninterruptsubroutine,eitheraRETorRETIinstructionmaybeexecuted.TheRETI

instructioninadditiontoexecutingareturntothemainprogramalsoautomaticallysetstheEMI

bithightoallowfurtherinterrupts.TheRETinstructionhoweveronlyexecutesareturntothemain

programleavingtheEMIbitinitspresentzerostateandthereforedisablingtheexecutionoffurther

interrupts.

Application Circuits

Direct Driving – HT45F2020

VDD

VSS

PTP

PTPB

IO1

12V

100μF

IO2

150Ω/2W

200Ω/0.5W

Speaker

Note:ThePTPandPTPBsignalsarethePTMcomplementaryoutputs.

HT45F2020 датащи(PDF) 65 Page - Holtek Semiconductor Inc