数字逻辑1-1课件

DigitalDesign

—PinciplesandPractices

Chapter1:Introduction

Whystudydigitaldesign?

DigitalsignalDigitalsystemThearrangementofthecourse

WhyStudyDigitalDesign?Look“underthehood”ofcomputersSolidunderstanding-->betterprogrammerwhenawareofhardwareresourceissuesElectronicdevicesbecomingdigitalEnabledbysmallerandmorecapablechipsEnables:Betterdevices:cameras,cars,medicaldevices,TVs...Newdevices:smartphones,robots,..Knownas“embeddedsystems”ThousandsofnewdeviceseveryyearDesignersneeded:Potentialcareerdirection1995Portablemusicplayers1997Satellites1999Cellphones2001DVDplayersVideorecordersMusicalinstruments2003CamerasTVs???20052007Yearsshownaboveindicatewhendigitalversionbegantodominate(Notthefirstyearthatadigitalversionappeared)SignalsinelectriccircuitRealsignal:voice,music,movingpicture…Analogsignal:voltagechangedwithtime...Digitalsignal:samplingvaluesfromanalog

FromAnalogtoDigitalSampling—hold—changetodigital0.85:110110010.81:110011110.65:101001100.49:011111010.39:01100011……DigitindecimalsystemDigitinbinarysystemTheproblemforAnalogsignalEasytobedisturbShiftwithtemperatureHardtoberecordedCannotexpressabstractinformationTheadvantageofdigitalsignalOneachdataline,thesignalisverysimpleNotinfluencedbycircumstanceanddeviceCanberecordedandtransmittedeasilyAnyinformationcanbecoded

DigitalsignalDigitalsignal:thestringof1and0

1:Highvoltageorthepowersource;0:Lowvoltageortheground;Useseverallinestotransmitonedigit;Onlychangedindiscretetime!Onebinarydigitisabit.Onebytehas8bits.DigitalsystemAnyinputsandoutputscanonlybe1or0!Foreachoutput,itsstatemustbegetfromalltheinputs.Basiclogicindigitalsystem

NOTgate(inverter,INV)BufferBasiclogicindigitalsystem

ANDgate

diagramequationTruthtableThreeformsofalogicBasiclogicindigitalsystem

ORgate

OtherBasiclogicNANDNOROtherBasicdevicesXORBuffer:y=aInverter:y=a'basiclogicsystemwithoneormoreinputsbasiclogicsystemwithoneormoreinputsTwoclassesofdigitalcircuit

Withoutmemoryandstates

Combinationallogic

SequentiallogicWithmemoryandstates

Theintegratedcircuit:IC

SSI:1to20gates;simpledevices60s(SmallScaleIntegrated)MSI:20to200gates;functionaldevices70s(MediumScaleIntegrated)LSI:200to200000gates;complexdevicesorsimplesystems80s(LargeScaleIntegrated)VLSI:?

systemsonchip(SOC)90s

(VeryLargeScaleIntegrated)Moore’slaw:Doublinginevery18months

Moore’slawMoore’sLawICcapacitydoublingaboutevery18monthsforseveraldecadesKnownas“Moore’sLaw”afterGordonMoore,co-founderofIntelPredictedin1965predictedthatcomponentsperICwoulddoubleroughlyeveryyearorsoThefigureontherightdepictsrelatedphenomenaForaparticularnumberoftransistors,theICareashrinksbyhalfevery18monthsConsiderhowmuchshrinkingoccursinjust10years(trydrawingit)EnablesincrediblypowerfulcomputationinincrediblytinydevicesToday’sICsholdbillionsoftransistorsThefirstPentiumprocessor(early1990s)neededonly3millionAnIntelPentiumprocessorIChavingmillionsoftransistorsThetargetofdigitaldesignGatesdesign

DesignbasicdevicebytransistorsFunctionaldesign

Designfunctionalcircuitsbybasicdevice

combinationallogic

sequentiallogicThearrangementofthecourse

Teachin32times:ArithmeticanddeviceChap.

1,2,3

7

CombinationalcircuitChap.

4,5,6

10

SequentialcircuitChap.

7,8,9

14MemoryandADC/DAC

1结束语当你尽了自己