HT66F019 datasheet(158/175 Pages) HOLTEK

158 / 175 page

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HT66F019

A/D Flash MCU with EEPROM

HT66F019

A/D Flash MCU with EEPROM

LVD Operation

TheLowVoltageDetectorfunctionoperatesbycomparingthepowersupplyvoltage,VDD,witha

pre-specifiedvoltagelevelstoredintheLVDCregister.Thishasarangeofbetween2.0Vand4.0V.

Whenthepowersupplyvoltage,VDD,fallsbelowthispre-determinedvalue,theLVDObitwillbe

sethighindicatingalowpowersupplyvoltagecondition.WhenthedeviceisintheSLEEPand

IDLEmode,thelowvoltagedetectorwillremainactiveiftheLVDENbitishigh.Afterenabling

theLowVoltageDetector,atimedelaytLVDSshouldbeallowedforthecircuitrytostabilisebefore

readingtheLVDObit.NotealsothatastheVDDvoltagemayriseandfallratherslowly,atthe

voltagenearsthatofVLVD,theremaybemultiplebitLVDOtransitions.

VDD

LVDEN

LVDO

VLVD

tLVDS

LVD Operation

TheLowVoltageDetectoralsohasitsowninterruptwhichiscontainedwithinoneoftheMulti-

functioninterrupts,providinganalternativemeansoflowvoltagedetection,inadditiontopolling

theLVDObit.TheinterruptwillonlybegeneratedafteradelayoftLVDaftertheLVDObithasbeen

sethighbyalowvoltagecondition.Inthiscase,theLVFinterruptrequestflagwillbeset,causing

aninterrupttobegeneratedifVDDfallsbelowthepresetLVDvoltage.Thiswillcausethedeviceto

wake-upfromtheSLEEPorIDLEMode,howeveriftheLowVoltageDetectorwakeupfunctionis

notrequiredthentheLVFflagshouldbefirstsethighbeforethedeviceenterstheSLEEPorIDLE

Mode.

WhenLVDfunctionisenabled,itisrecommencedtoclearLVDflagfirst,andthenenablesinterrupt

functiontoavoidmistakeaction.

HT66F019 Datasheet(PDF) 158 Page - Holtek Semiconductor Inc