電子信息類專業(yè)英語

書名：電子信息類專業(yè)英語ISBN：978-7-111-25689-2出版社：機械工業(yè)出版社本書配有電子課件1電子信息類專業(yè)英語機械工業(yè)出版社同名教材配套電子教案溫丹麗高源制作

2

PassageOne

DigitalCircuits

機械工業(yè)出版社1．Howcanadigitalelectricsystemperformthetask?2．Whatisabit?3PassageOne

DigitalCircuits

WordsandExpressionsdiscrete[

5

:

]a. 不連續(xù)的，離散的quartz[kwC:ts]n.

石英binary[5bainEri]a. 二進位的bit[bit]n. [計]位，比特relay[5ri:lei]n. [電工]繼電器vacuum[5vAkjuEm]a. 真空的

resistor[ri5zistE]n. [電]電阻器capacitor[kE5pAsitE]n.

電容器package[5pAkidV]n. 包裹，包dimension[di5menFEn]n. 尺寸，尺度機械工業(yè)出版社4PassageOne

DigitalCircuits

dissipation[7disi5peiFEn]n. 消散，分散instrumentation[7instrumen5teiFEn]n.

使用儀器synthesis[5sinWisis]n.

綜合，合成proportional[prE5pC:FEnl]a.

成比例的transmit[trAnz5mit]v.

傳輸，轉送immune[i5

:n]a. 免疫的interference[7intE5fiErEns]n.沖突，干涉ample[5Ampl]a. 充足的，豐富的modification[7mCdifi5keiFEn]n. 更改，修改，修正pulse[pQls]n. 脈搏，脈沖inadequate[in5Adikwit]a. 不充分的，不適當?shù)膁igitalcommunication 數(shù)字通信系統(tǒng)

機械工業(yè)出版社5PassageOne

DigitalCircuits

TextAnelectronicsystemisanorderlycollectionofinteractingelectronicbuildingblocksthatperformsadesiredtask.Adigitalelectronicsystemperformsthetasksbydealingwithdiscretequantities.Discretequantitiesareintegral,fractional,ormixednumbersthatrepresent,tothenearestleastsignificantdigit,somequantitiesintherealworldsuchastemperature,pressure,ordistance.Incontrastthereareanalogelectronicsystemsthatrepresentthesequantitiesonacontinuousscale.機械工業(yè)出版社6PassageOne

DigitalCircuits

Manymeasurementsmayberepresentedineitherdigitaloranalogform.Forexample,timehasbeenrepresentedoverthecenturiesinananalogformtheanglesubtendedbythesmallandlargehandsoftheclockprovidedalltheinformationabouttimethatwasdesired.Forbetterresolutionintime,asecondhandwasadded.Inthelastseveralyearsatotallynewmethodwasdevelopedtomeasureanddisplaytime.Themethodisbasedontheoscillationfrequencyofaquartzcrystalthatinconjunctionwithdigitalcircuitryanddigitaldisplaytechnologypresentsthetimeinformationindigitalformasanumber.機械工業(yè)出版社7PassageOne

DigitalCircuits

Manymeasurementsmayberepresentedineitherdigitaloranalogform.Forexample,timehasbeenrepresentedoverthecenturiesinananalogformtheanglesubtendedbythesmallandlargehandsoftheclockprovidedalltheinformationabouttimethatwasdesired.Forbetterresolutionintime,asecondhandwasadded.Inthelastseveralyearsatotallynewmethodwasdevelopedtomeasureanddisplaytime.Themethodisbasedontheoscillationfrequencyofaquartzcrystalthatinconjunctionwithdigitalcircuitryanddigitaldisplaytechnologypresentsthetimeinformationindigitalformasanumber.8PassageOne

DigitalCircuits

Digitalprocessingofinformationhasindeedbecomewidespreadinthisdecade；inadditiontodigitalwatches,clocks,andcalculators,therearenumerousdigitalcontrollers(microcomputers)usedinhomeappliancesandautomobiles.Indigitalelectronicsystems,informationisrepresentedbybinarydigits,bits.Abitmayassumeeitheroneoftwovalues:0or1.Amathematicalsystemthatusesonlytwodigitsiscalledabinarysystem.ItsfoundationswerelaidbytheBritishMathematicianGeorgeBoole(1815~1864)inhisclassictreatiseAnInvestigationoftheLawsofThought(1854).機械工業(yè)出版社9PassageOne

DigitalCircuits

Theinventionofthetransistormaybeviewedasanothermajorbreakthroughindigitalinformationprocessing.Thevolumeoccupiedbyatransistorisaboutonehundredthofthatoccupiedbyeitherarelayoravacuumtube,andasimilarratioholdsforthepowerdissipatedbythedevicesundercomparison.Thetransistoralsoprovidethetechnologicalbaseforthedevelopmentofintegratedcircuits,anensembleofmanytransistorthatareinterconnectedtoperformaspecifiedfunction.機械工業(yè)出版社10PassageOne

DigitalCircuits

Thefirstintegratedcircuitwasdevelopedin1958,whichisastartofarevolutionarychangeintheartofelectronicsdesign.Intheinitialstagesofsemiconductortechnologydevelopment,thedeviceswereclassifiedaseitherdiscreteorintegrated.Adigitalintegratedcircuitconsistedofseveraltransistorsandsometimesalsoofpassivecomponents(resistorsandcapacitors)onasemiconductorsubstratethatwereinterconnectedtoperformalogicalfunction.Suchlogicalfunctionimplementingsimplelogicoperationsprovidedthebuildingblocksfortherealizationofswitchingnetworks.Furtheradvancesintechnologyenabledfabricationofmanytransistorsononesemiconductorsubstrate.Thelevelofcomplexityincreased,broadeningthescopeofcircuitscontainedinonepackage.Thesenewcircuitscouldcount,performaddition,subtraction,ormultiplicationoftwobinarydigits,comparetheirbinaryvalues,andrealizemorecomplexlogicaloperations.機械工業(yè)出版社11PassageOne

DigitalCircuits

Scientistsandengineersengagedinthedevelopmentofthetransistortechnologymetthechallengeofthenextlevelofcomplexity.Theindividualcomponentsonasemiconductorsubstratewerefurtherdecreasedindimensionsandsimilarlytheirpowerdissipationwasreduced.Deviceswithsome100,000transistorsononesubstratebecameareality,andpracticallimitationswerenowsetprimarilybytheinputandoutputterminalstothe“outsideworld”ratherthanbythecomplexityandnumberoftransistorsonasubstrate.機械工業(yè)出版社12PassageOne

DigitalCircuits

Digitalcircuitsarebeingusedinsuchdiversefieldsasinformationstorage,medicalinstrumentation,processcontrol,calculatorsandcomputers,airtraffic,digitalcommunications,andinvoiceandtonesynthesis.Digitaltechniquesarealsobeginningtobeusedinareasthattraditionallyappliedanalogtechniques.Forexample,assumewedesiretosendtemperatureinformationfrompointAtopointBinanindustrialplant.Alsoassumethattheinformationisinformofananalogvoltagethatisproportionaltothevalueofthetemperaturethatwedesiredtotransmit.機械工業(yè)出版社13PassageOne

DigitalCircuits

Thetransmissionmediummaybeacableoramodulatedradio-frequencywave.Ineithercasethetransmissionisnotimmunetointerferencethatmodifiesthecontentofthetransmittedmessage.Supposethatanaccuracyofonepartin1000isdesired.Thisimpliesthattheinterferencemustbekeptbelowonethousandthofthetransmitted(analog)quantitytosatisfyouraccuracyspecifications.Thismaybedifficulttorealizeinanindustrialenvironmentinwhichampleelectricinterference(noise)isgeneratedbymotors,arcwelding,relays,andthelike.14PassageOne

DigitalCircuits

Ontheotherhandthatsameinformationabouttemperaturemaybetransmittedindigitalform.Suchdigitaltransmissionusesthebinarysystem,whichpresentsinformationinformofapulsetrainthatissuitablycoded.HereweareconcernedonlywhetherduringacertaintimeintervalthepulseisONorOFF.ModificationoftheONorOFFpulsesresultingfromenvironmentalinterferencemustbeverysubstantialtochangetheinformationcontentofthetransmission.Thusthedigitalsystemismuchmoreimmunetointerferenceandismorelikelytobeusedinmanyapplicationsinwhichananalogsystemwouldbeinadequate.機械工業(yè)出版社15PassageOne

DigitalCircuits

ExercisesⅠ.Matchtheitemslistedinthefollowingtwocolumns.1.digitalcircuits a.開關網(wǎng)絡2.significantdigit b.有效數(shù)字

3.binarydigits c.二進制數(shù)4.digitalinformationprocess d.數(shù)字通信5.integratedcircuit e.數(shù)字信息處理6.logicalfunction f.數(shù)字電路7.digitalcommunication g.集成電路8.switchingnetwork h.邏輯功能機械工業(yè)出版社16PassageOne

DigitalCircuits

Ⅱ.Completethefollowingsentencesaccordingtothetext.1.Adigitalelectronicsystemperformsthetasksbydealingwith

quantities.2.Indigitalelectronicsystems，informationisrepresentedby

digits.3.Thefirstintegratedcircuitwasdevelopedin

.4.

techniquesarealsobeginningtobeusedinareasthattraditionallyappliedanalogtechniques.5.Anadditionalareawhereadigitalsystemoftenhasanadvantageoverananalogsystemisinitspower

.機械工業(yè)出版社17

Classisover!Havearest!追求機械工業(yè)出版社18電子信息類專業(yè)英語機械工業(yè)出版社同名教材配套電子教案溫丹麗高源制作

19機械工業(yè)出版社PassageTwo

DigitalLogicCircuits1.Whycanwesaythebinarysystemistheprimarylanguageofthecomputer?2.WhatisthedifferencebetweentheANDgateandtheNANDgate?20PassageTwoDigitalLogicCircuits

WordsandExpressionsflip-flop[5flipflCp]n.

觸發(fā)器latch[lAt]n. 鎖存器asynchronous[eI`siNkrEnEs]a. [電]異步的arbitrary[5

:bitrEri]a.

任意的，武斷的synchronous[5siNkrEnEs]a.

同時的，同步的arrangement[E5reIn

]n. 電路，裝置機械工業(yè)出版社21PassageTwo

DigitalLogicCircuits

Text1.NumberSystemsThenumbersystemwithwhichwearemostfamiliaristhebase10,ordecimalsystem.Recenttechnologicaldevelopmentshavecreatedtheneedforothernumbersystems.Theelectroniccomputer,forexample,requiredthedevelopmentofsystemthatwaseasilyadaptedtoelectronicprocesses.Thesenumbersystemswerethebinary(base2),octal(base8),andhexadecimal(base16).Thebinarysystemistheprimarylanguageofthecomputer.Theoctalandhexadecimalsystemsareusuallyusedforcommunicationwiththecomputerandforstorageofinformationwithinthecomputer.Sincecomputerscanonlyprocessbinarynumbersornumberscodedinothersystemssuchasoctalandhexadecimal,thedecimalsystemmustbeconvertedtooneoftheseothersystemsbeforeitcanbeprocessedbycomputer.Whenthecomputerfinishesitsoperationsontheinformation,theoutputisprintedordisplayedinnumbersystemotherthandecimal,andthistoomustbeconverted,thistimebacktothedecimalsystem.機械工業(yè)出版社22PassageTwoDigitalLogicCircuits

Digitalelectronicsisa“l(fā)ogical”science.Logic,generallyspeaking,isthescienceofformalprinciplesofreasoning.Digitallogicisthescienceofreasoningwithnumbersaspecialcircuitcalledagatewhichcanperformnearlyall-digitalfunctions.Ifthelogicoperationistoocomplexforonegate,itcanalmostalwaysbeimplementedthroughtheuseofacombinationofgates.Theseextendedlogiccircuitsarecombinationallogic.機械工業(yè)出版社23PassageTwoDigitalLogicCircuits

2.LogicalGates(1)ANDgateandNANDgateTwoofthemostbasiclogicfunctionsaretheANDandtheNAND.Thedifferencebetweenthesefunctionsisthattheyarecomplements.Thismeanstheyareoppositeinfunction.TheANDgateprovidesafunctionindigitallogicwhichgivesahighoutputwhenallofitsinputsarehigh.Fig.2-1showsthesymbolusedtorepresentanANDgate.Inthiscase,therearetwoinputs,AandB,andoneoutput,C.Gateswithasmanyaseightinputsareavailable.機械工業(yè)出版社24PassageTwoDigitalLogicCircuits

AnANDgatewillprovideanoutputhigh(1)onlywhenbothinputs(orallinputsiftherearemorethantwo)arehigh(1).Thisrelationshipisusuallywritteninthefollowingway:AB=CAboveexpressingisnormallysaidinthefollowingway:“ifAequals1andBequals1thenCwillequal1”or“AandBequalC”.TheNANDgateisamorecommongatethantheANDgate(Fig.2-2).ItisthecomplementoftheANDgate,meaningthatitisjusttheoppositeinlogicstate.機械工業(yè)出版社25PassageTwoDigitalLogicCircuits

Fig.2-1

ANDGateFig.2-2

NANDGate機械工業(yè)出版社26PassageTwoDigitalLogicCircuits

NANDgatesfrequentlyarecheaperandeasiertousethanANDgatesbecauseelectronicallytheyaresimpler.TheNinfrontoftheANDmeans“not”AND.ThelogicisalsowrittendifferentlyforaNgatewhenitisplacedinaformula.AnoverscoreofbarisusedtoindicateaNOTorinverted(complement)condition.Forexample:機械工業(yè)出版社27PassageTwoDigitalLogicCircuits

Itmeans“AandBequalsNOTC”.InthecaseoftheNANDgatetheoutputwillbehigh(1)exceptwhentheinputsareallhigh.Whenallinputsarehigh,theoutputoftheNANDgatewillbelow(0).（2）ORgateTheORgate(Fig.2-3)providesafunctionthatwillgiveahighoutput(1)whenanyoneoftheinputsisatahigh(1)logiclevel.Thisfunctionasusuallywritteninthefollowingway:A+B=CTheplus(+)signisthesymbolusedtoindicateanORlogicfunction.Thisexpressionisspokeninthefollowingway:“ifAORBequals1thenCequals1”.機械工業(yè)出版社28PassageTwoDigitalLogicCircuits

Fig.2-3

ORGate機械工業(yè)出版社29PassageTwoDigitalLogicCircuits

（3）CombininglogicfunctionsIndividuallogicgatesarebuildingblocks.Theycanstandaloneifonlyasinglelogicfunctionisneeded,ortheycanbecombinedwithothergatesformorecomplexoperations.Therearetimeswhenitisadvantageoustosubstituteonekindofgateforanother.Whatdoesacircuitdesignerdo,forinstance,ifaANDgateisneededandonlyNANDgatesareavailable?Itisanindicatoroftheversatilityandflexibilityofdigitalintegratedcircuitsthatthedesignercanconfigurethegatesonhandtomeetthecircuitneeds.機械工業(yè)出版社30PassageTwoDigitalLogicCircuits

3.Flip-FlopandClockMicroprocessorsemploybothlatchesandflip-flops.ThebasicRSlatchesnotaflip-flopbecauseitisanasynchronousdevice(itisunlocked).Thatisalatchfuncti