Lesson 19 Logic Gates电子技术专业英语教程

2020/5/24,电子技术专业英语教程,1,Lesson19LogicGates电子技术专业英语教程冯新宇主编电子工业出版社,Unit7DigitalLogicCircuit,2020/5/24,电子技术专业英语教程,2,Lesson19LogicGates,BackgroundsTexttourLanguageinuseVocabularyStructureReading/writingtechniques,2020/5/24,电子技术专业英语教程,3,TerminologyORing或操作，或运算ANDing与操作，与运算Booleanalgebra【计】逻辑代数;布尔代数,Backgrounds,2020/5/24,电子技术专业英语教程,4,Texttour,OutlineWhatis“gates”andBooleanalgebra?NOTOperationTruthtableSymbolicofNOTgateExampleORoperationTruthtableSymbolicofORgateDiodeORgateExampleANDoperationTruthtableSymbolicofANDgateDiodeANDgateExample,2020/5/24,电子技术专业英语教程,5,Whatis“gates”andBooleanalgebra?,Digitalcircuitscontainhardwareelementscalled“gates”thatperformlogicoperationsonbinarynumbers.Devicessuchastransistorscanbeusedtoperformthelogicoperations.Booleanalgebraisamathematicalsystemthatprovidesthebasisfortheselogicoperations.GeorgeBoole,anEnglishmathematician,introducedthistheoryofdigitallogic.ThetermBooleanvariableisusedtomeanthetwo-valuedbinarydigit1or0.Booleanalgebrausesthreebasiclogicoperationsnamely,NOT,OR,andAND.Theseoperationsaredescribednext.,2020/5/24,电子技术专业英语教程,6,NOTOperation,TheNOToperationinvertsorprovidestheonescomplementofabinarydigit.Thisoperationtakesasingleinputandgeneratesoneoutput.TheNOToperationofabinarydigitprovidesthefollowingresult:NOT1=0NOT0=1,2020/5/24,电子技术专业英语教程,7,NOTOperation_Truthtable,Therefore,NOTofaBooleanvariableA,writtenas(orA)is1ifandonlyifAis0.Similarly,is0ifandonlyifAis1.Thisdefinitionmayalsobespecifiedintheformofatruthtable:Notethatatruthtablecontainstheinputsandoutputsofdigitallogiccircuits.,2020/5/24,电子技术专业英语教程,8,NOTOperation_SymbolicofNOTgate,ANOTgateisalsoreferredtoasan“inverter”becauseitinvertsthevoltagelevels.transistoractsasaninverter.A0-voltattheinputgeneratesa5-voltoutput;a5-voltinputprovidesa0-voltoutput.,Figure19-1NOTgate,2020/5/24,电子技术专业英语教程,9,NOTOperation_Example,The74HC04(or74LS04)isahexinverter14-pinchipcontainingsixindependentinvertersinthesamechipasshowninFigure19-2.ComputersnormallyincludeaNOTinstructiontoperformtheonescomplementofabinarynumberonabit-by-bitbasis.An8-bitcomputercanperformNOToperationonan8-bitbinarynumber.Forexample,thecomputercanexecuteaNOTinstructiononan8-bitbinarynumber01101111toprovidetheresult10010000.Thecomputerutilizesaninternalelectroniccircuitconsistingofeightinverterstoinvertthe8-bitdatainparallel.,Figure19-2Pindiagramforthe74HC04or74LS04,HexInverter74LS04,2020/5/24,电子技术专业英语教程,10,ORoperation,TheORoperationfortwovariablesAandBgeneratesaresultof1ifAorB,orboth,are1.However,ifbothAandBarezero,thentheresultis0.Aplussign+(logicalsum)orsymbolisnormallyusedtorepresentOR.ThefourpossiblecombinationsofORingtwobinarydigitsare0+0=00+1=11+0=11+1=1,2020/5/24,电子技术专业英语教程,11,ORoperation_TruthtableandSymbolicofNOTgate,Atruthtableisusuallyusedwithlogicoperationstorepresentallpossiblecombinationsofinputsandthecorrespondingoutputs.ThetruthtablefortheORoperationis:Figure19-3ORgate,2020/5/24,电子技术专业英语教程,12,OROperation_DiodeORgate,Thediodeisaswitch,anditcloseswhenthereisavoltagedropof0.6Vbetweentheanodeandthecathode.Supposethatavoltagerangeof0to2Visconsideredaslogic0andavoltageof3to5Vislogic1.IfbothAandBareatlogic0(say1.5V)withavoltagedropacrossthediodesof0.6Vtoclosethediodeswitches,acurrentflowsfromtheinputsthroughRtoground,andtheoutputCwillbeat1.5V-0.6V=0.9V(logic0).Ontheotherhand,ifoneorbothinputsareatlogic1(say4.5V)theoutputCwillbeat4.5-0.6V=3.9V(logic1).Therefore,thecircuitactsasanORgate.,Figure19-4DiodeORgate,2020/5/24,电子技术专业英语教程,13,OROperation_Example,The74HC32(or74LS32)isacommerciallyavailablequad2-input14-pinORgatechip.Thischipcontainsfour2-input/l-outputindependentORgatesasshowninFigure19-5.,Figure19-5Pindiagramfor74HC32or74LS32,74LS32,2020/5/24,电子技术专业英语教程,14,ANDoperation,TheANDoperationfortwovariablesAandBgeneratesaresultof1ifbothAandBare1.However,ifeitherAorB,orboth,arezero,thentheresultis0.ThedotandsymbolarebothusedtorepresenttheANDoperation.TheANDoperationbetweentwobinarydigitsis00=001=010=011=1,2020/5/24,电子技术专业英语教程,15,ANDoperation_TruthtableandSymbolicofNOTgate,ThetruthtablefortheANDoperationisFigure19-6ANDgate,2020/5/24,电子技术专业英语教程,16,ANDOperation_DiodeORgate,AswedidfortheORgate,letusassumethattherange0to+2Vrepresentslogic0andtherange3to5Vislogic1.Now,ifAandBarebothHIGH(say3.3V)andtheanodeofbothdiodesat3.9V,theswitchesinD1andD2close.Acurrentflowsfrom+5VthroughresistorRto+3.3Vinputtoground.TheoutputCwillbeHIGH(3.9V).Ontheotherhand,ifalowvoltage(say0.5V)isappliedatAandahighvoltage(3.3V)isappliedatB.ThevalueofRisselectedinsuchawaythat1.1VappearsattheanodesideofD1atthesametime3.9VappearsattheanodesideofD2.Acurrentflowsfromthe+5VinputthroughRandthediodestoground.OutputCwillbelow(1.1V)becausetheoutputwillbelowerofthetwovoltages.Thus,itcanbeshownthatwheneitheroneorbothinputsarelow,theoutputislow,sothecircuitworksasanANDgate.,Figure19-7DiodeANDgate,2020/5/24,电子技术专业英语教程,17,ANDOperation_Example,The74HC08(or74LS08)isacommerciallyavailablequad2-input14-pinANDgatechip.Thischipcontainsfour2-input/l-outputindependentANDgatesasshowninFigure19-8.,Figure19-8Pindiagramfor74HC08or74LS08,74LS08,2020/5/24,电子技术专业英语教程,18,VocabularyAcquisitionstimulusmarginevaluationancillarybriefStructureReading/writingtechniques,Languageinuse,2020/5/24,电子技术专业英语教程,19,Vocabulary,2020/5/24,电子技术专业英语教程,20,Acquisitionindictionary,Theactofacquiring.获得，取得Somethingacquired,especiallyanadditiontoanestablishedcategoryorgroup.获得物Theprocessoflocatingasatellite,guidedmissile,ormovingtargetsothatitstrackororbitcanbedetermined.搜索，探测,2020/5/24,电子技术专业英语教程,21,Acquisitionintext,Anacquisitioninstrumentusuallyanoscilloscopeorlogicanalyserisprobablythefirstthingthatcomestomindwhenyouthinkaboutmakingelectronicmeasurements.当进行电子测量时，人们首先想到的很可能是一件采集仪器通常是示波器或逻辑分析仪。,2020/5/24,电子技术专业英语教程,22,Acquisitioninuse,aircrafttargetacquisition空中目标的搜索high-speeddataacquisition高速数据采集languageacquisition语言习得techniqueacquisition技术引进,2020/5/24,电子技术专业英语教程,23,Stimulusindictionary,Somethingcausingorregardedascausingaresponse.刺激因素Anagent,anaction,oraconditionthatelicitsoracceleratesaphysiologicalorpsychologicalactivityorresponse.刺激物,2020/5/24,电子技术专业英语教程,24,Stimulusintext,Thetoolsetfordigitaldesigncharacterizationdiffersfromitscounterpartinanalog/mixedsignaldesign,butbothmustincludestimulusinstrumentsandacquisitioninstruments.Thesignalsource,orsignalgenerator,isthestimulussourcethatpairswithanacquisitioninstrumenttocreatethetwoelementsofacompletemeasurementsolution.用于数字设计特性评价的测量仪器和用于模拟/混合信号设计的测量仪器是不一样的，但两者一定都包含激励信号产生仪器和信号采集仪器。信号源（或信号发生器）和采集仪器是构成一个完整测量解决方案的两大基本组成部分。,2020/5/24,电子技术专业英语教程,25,Stimulusinuse,underthestimulusofthishopeLightisastimulustogrowthinplants.,2020/5/24,电子技术专业英语教程,26,Marginindictionary,Anedgeandtheareaimmediatelyadjacenttoit;aborder.边缘，边界Theblankspaceborderingthewrittenorprintedareaonapage.空白Alimitinaconditionorprocess,beyondorbelowwhichsomethingisnolongerpossibleoracceptable:极限themarginofrealityhascrossedthemarginofcivilizedbehavior.,2020/5/24,电子技术专业英语教程,27,Marginindictionary,Anamountallowedbeyondwhatisneeded:余地Ameasure,quantity,ordegreeofdifference:差数Theminimumreturnthatanenterprisemayearnandstillpayforitself.边际收益Theborderofaleaf.树叶的边缘,2020/5/24,电子技术专业英语教程,28,Marginindictionary,Intelegraphy,ameasureoftheabilityofthereceivingapparatustocopywithtimingerrorsinthereceivedsignal.Inprinting,thespacesurroundingthetypearea,comprisinghead,tail,backandforedge.,2020/5/24,电子技术专业英语教程,29,Marginintext,Tociteanotherexample,engineersmustcharacterizetheiremergingdesignstoensurethatthenewhardwaremeetsdesignspecificationsacrossthefullrangeofoperationandbeyond.Thisisknownasmarginorlimittesting.举另外一个例子。为了确保新硬件在整个操作范围及该范围之外满足性能设计要求，工程师们必须对即将完成的设计进行特性评价。这就是所谓的“边缘测试或极限测试”。,2020/5/24,电子技术专业英语教程,30,Margininuse,byacomfortablemargin以较大的多数byanarrowmargin以微弱多数bya.margin以.之差,2020/5/24,电子技术专业英语教程,31,Margininuse,bindingmargin装订边continentalmargin大陆边缘currentmargin工作电流范围,电流容限designmargin设计余量errormargin误差容限,2020/5/24,电子技术专业英语教程,32,Margininuse,lowlevelnoisemargin低电平噪声容限magnitudemargin幅值裕度noisemargin噪声容限,噪声安全系数nominalmargin标称容限peakmargin峰值容限,2020/5/24,电子技术专业英语教程,33,Evaluationindictionary,Aprocesstodeterminewhetherornotanitemofhardwareorsoftwarecanperformaparticularrequiredfunctionortodeterminewhichoftwoormoreitemscanperformthefunctionbest.评价；鉴定Aprocesstoreduceanexpressiontoitssimplestformorasinglevalue.计算，求值,2020/5/24,电子技术专业英语教程,34,Evaluationintext,Asignalsourceisnothinglessthanthecornerstoneofalmostanyinstrumentationsetupusedinhardwaredesign,debug,orevaluationprojects信号源是用于硬件设计、调试、评价工程中的几乎任何一种测量配置的基础。,2020/5/24,电子技术专业英语教程,35,Evaluationinuse,accomplishmentevaluation学业成绩评定hazardevaluation危害评价lossevaluation损耗估算evaluationofdeterminants行列式的求值,2020/5/24,电子技术专业英语教程,36,Ancillaryindictionary,Subordinate:从属