数字电子技术(Floyd 第十版)课件Chapter -03-st.ppt
- 文档编号:11259586
- 上传时间:2023-05-30
- 格式:PPT
- 页数:44
- 大小:1.57MB
数字电子技术(Floyd 第十版)课件Chapter -03-st.ppt
《数字电子技术(Floyd 第十版)课件Chapter -03-st.ppt》由会员分享,可在线阅读,更多相关《数字电子技术(Floyd 第十版)课件Chapter -03-st.ppt(44页珍藏版)》请在冰点文库上搜索。
,DigitalFundamentalsTenthEditionFloyd,Chapter3,2008PearsonEducation,TheinverterperformstheBooleanNOToperation.WhentheinputisLOW,theoutputisHIGH;whentheinputisHIGH,theoutputisLOW.,Summary,TheInverter,A,X,LOW(0)HIGH
(1),HIGH
(1)LOW(0),Summary,TheInverter,Examplewaveforms:
A,X,A,X,Agroupofinverterscanbeusedtoformthe1scomplementofabinarynumber:
Binarynumber,1scomplement,10001101,01110010,TheANDgateproducesaHIGHoutputwhenallinputsareHIGH;otherwise,theoutputisLOW.Fora2-inputgate,thetruthtableis,Summary,TheANDGate,TheANDoperationisusuallyshownwithadotbetweenthevariablesbutitmaybeimplied(nodot).Thus,theANDoperationiswrittenasX=A.BorX=AB.,00011011,0001,A,B,X,A,B,X,Summary,Examplewaveforms:
A,X,TheANDoperationisusedincomputerprogrammingasaselectivemask.Ifyouwanttoretaincertainbitsofabinarynumberbutresettheotherbitsto0,youcouldsetamaskwith1sinthepositionoftheretainedbits.,TheANDGate,A,B,X,B,A,B,X,Summary,00000011,Example,Ifthebinarynumber10100011isANDedwiththemask00001111,whatistheresult?
Summary,TheANDGate,AMultisimcircuitisshown.XWG1isawordgeneratorsetinthecountdownmode.XLA1isalogicanalyzerwiththeoutputoftheANDgateconnectedtofirst(upper)lineoftheanalyzer.Whatsignaldoyouexpecttoonthisline?
Example,Solution,Theoutput(line1)willbeHIGHonlywhenalloftheinputsareHIGH.,TheORgateproducesaHIGHoutputifanyinputisHIGH;ifallinputsareLOW,theoutputisLOW.Fora2-inputgate,thetruthtableis,Summary,TheORGate,TheORoperationisshownwithaplussign(+)betweenthevariables.Thus,theORoperationiswrittenasX=A+B.,00011011,0111,A,B,X,A,B,X,Summary,Examplewaveforms:
A,X,TheORoperationcanbeusedincomputerprogrammingtosetcertainbitsofabinarynumberto1.,TheORGate,B,A,B,X,A,B,X,Summary,Example,ASCIIlettershavea1inthebit5positionforlowercaselettersanda0inthispositionforcapitals.(Bitpositionsarenumberedfromrighttoleftstartingwith0.)WhatwillbetheresultifyouORanASCIIletterwiththe8-bitmask00100000?
Solution,Theresultingletterwillbelowercase.,Summary,TheORGate,AMultisimcircuitisshown.XWG1isawordgeneratorsettocountdown.XLA1isalogicanalyzerwiththeoutput,Example,Solution,Theoutput(line1)willbeHIGHifanyinputisHIGH;otherwiseitwillbeLOW.,connectedtofirst(top)lineoftheanalyzer.Thethree2-inputORgatesactasasingle4-inputgate.Whatsignaldoyouexpectontheoutputline?
TheNANDgateproducesaLOWoutputwhenallinputsareHIGH;otherwise,theoutputisHIGH.Fora2-inputgate,thetruthtableis,Summary,TheNANDGate,00011011,1110,A,B,X,A,B,X,Summary,Examplewaveforms:
A,X,TheNANDgateisparticularlyusefulbecauseitisa“universal”gateallotherbasicgatescanbeconstructedfromNANDgates.,TheNANDGate,B,A,B,X,A,B,X,Summary,TheNANDGate,Question,Howwouldyouconnecta2-inputNANDgatetoformabasicinverter?
Summary,TheNANDGate,AMultisimcircuitisshown.XWG1isawordgeneratorsetinthecountupmode.Afour-channeloscilloscopemonitorstheinputsandoutput.Whatoutputsignaldoyouexpecttosee?
Example,Solution,Theoutput(channelD)willbeLOWonlywhenalloftheinputsareHIGH.,Inputs,TheNORgateproducesaLOWoutputifanyinputisHIGH;ifallinputsareHIGH,theoutputisLOW.Fora2-inputgate,thetruthtableis,Summary,TheNORGate,00011011,1000,A,B,X,A,B,X,Summary,Examplewaveforms:
A,X,TheNORoperationwillproduceaLOWifanyinputisHIGH.,TheNORGate,B,A,B,X,A,B,X,Summary,Example,WhenistheLEDisONforthecircuitshown?
Solution,TheLEDwillbeonwhenanyofthefourinputsareHIGH.,TheXORgateproducesaHIGHoutputonlywhenbothinputsareatoppositelogiclevels.Thetruthtableis,Summary,TheXORGate,00011011,0110,A,B,X,A,B,X,Summary,Examplewaveforms:
A,X,NoticethattheXORgatewillproduceaHIGHonlywhenexactlyoneinputisHIGH.,TheXORGate,B,A,B,X,A,B,X,Summary,Question,IftheAandBwaveformsarebothinvertedfortheabovewaveforms,howistheoutputaffected?
Thereisnochangeintheoutput.,TheXNORgateproducesaHIGHoutputonlywhenbothinputsareatthesamelogiclevel.Thetruthtableis,Summary,TheXNORGate,00011011,1001,A,B,X,A,B,X,Summary,Examplewaveforms:
A,X,NoticethattheXNORgatewillproduceaHIGHwhenbothinputsarethesame.Thismakesitusefulforcomparisonfunctions.,TheXNORGate,B,A,B,X,A,B,X,Summary,Question,IftheAwaveformisinvertedbutBremainsthesame,howistheoutputaffected?
Theoutputwillbeinverted.,A,B,X,TwomajorfixedfunctionlogicfamiliesareTTLandCMOS.AthirdtechnologyisBiCMOS,whichcombinesthefirsttwo.Packagingforfixedfunctionlogicisshown.,Summary,FixedFunctionLogic,DIPpackageSOICpackage,Somecommongateconfigurationsareshown.,Summary,FixedFunctionLogic,Logicsymbolsshowthegatesandassociatedpinnumbers.,Summary,FixedFunctionLogic,DatasheetsincludelimitsandconditionssetbythemanufactureraswellasDCandACcharacteristics.Forexample,somemaximumratingsfora74HC00Aare:
Summary,FixedFunctionLogic,AProgrammableLogicDevice(PLD)canbeprogrammedtoimplementlogic.TherearevarioustechnologiesavailableforPLDs.ManyuseaninternalarrayofANDgatestoformlogicterms.ManyPLDscanbeprogrammedmultipletimes.,Summary,ProgrammableLogic,Summary,ProgrammableLogic,Ingeneral,therequiredlogicforaPLDisdevelopedwiththeaidofacomputer.ThelogiccanbeenteredusingaHardwareDescriptionLanguage(HDL)suchasVHDL.LogiccanbespecifiedtotheHDLasatextfile,aschematicdiagram,orastatediagram.,Summary,Example,AtextentryforaprogrammingaPLDinVHDLasa2-inputNANDgateisshownforreferenceinthefollowingslide.Inthiscase,theinputsandoutputsarefirstspecified.Thenthesignalsaredescribed.AlthoughyouareprobablynotfamiliarwithVHDL,youcanseethattheprogramissimpletoread.,Summary,ProgrammableLogic,entityNandGateisport(A,B:
inbit;LED:
outbit);endentityNandGate;architectureGateBehaviorofNandGateissignalA,B:
bit;beginX=AnandB;LED=X;endarchitectureGateBehavior;,SelectedKeyTerms,InverterTruthtableTimingdiagramBooleanalgebraANDgate,Alogiccircuitthatinvertsorcomplementsitsinputs.,Atableshowingtheinputsandcorrespondingoutput(s)ofalogiccircuit.,Adiagramofwaveformsshowingthepropertimerelationshipofallofthewaveforms.,Themathematicsoflogiccircuits.,AlogicgatethatproducesaHIGHoutputonlywhenallofitsinputsareHIGH.,SelectedKeyTerms,ORgateNANDgateNORgateExclusive-ORgateExclusive-NORgate,AlogicgatethatproducesaHIGHoutputwhenoneormoreinputsareHIGH.,AlogicgatethatproducesaLOWoutputonlywhenallofitsinputsareHIGH.,AlogicgatethatproducesaLOWoutputwhenoneormoreinputsareHIGH.,AlogicgatethatproducesaHIGHoutputonlywhenitstwoinputsareatoppositelevels.,AlogicgatethatproducesaLOWoutputonlywhenitstwoinputsareatoppositelevels.,Thetruthtablefora2-inputANDgateis,2008PearsonEducation,Quiz,00011011,00011011,1000,00011011,00011011,0111,a.,b.,c.,d.,0110,0001,Thetruthtablefora2-inputNORgateis,2008PearsonEducation,Quiz,00011011,00011011,00011011,00011011,a.,b.,c.,d.,0110,0001,1000,0111,Thetruthtablefora2-inputXORgateis,2008PearsonEducation,Quiz,00011011,00011011,00011011,00011011,a.,b.,c.,d.,0110,0001,1000,0111,2008PearsonEducation,Quiz,4.Thesymbolisfora(n),a.ORgateb.ANDgatec.NORgated.XORgate,A,B,X,2008PearsonEducation,Quiz,5.Thesymbolisfora(n),a.ORgateb.ANDgatec.NORgated.XORgate,A,B,X,2008PearsonEducation,Quiz,6.AlogicgatethatproducesaHIGHoutputonlywhenallofitsinputsareHIGHisa(n),a.ORgateb.ANDgatec.NORgated.NANDgate,2008PearsonEducation,Quiz,7.TheexpressionX=A+Bmeans,a.AORBb.AANDBc.AXORBd.AXNORB,2008PearsonEducation,Quiz,8.A2-inputgateproducestheoutputshown.(Xrepresentstheoutput.)Thisisa(n),a.ORgateb.ANDgatec.NORgated.NANDgate,A,X,B,2008PearsonEducation,Quiz,9.A2-inputgateproducesaHIGHoutputonlywhentheinputsagree.Thistypeofgateisa(n),a.ORgateb.ANDgatec.NORgated.XNORgate,2008PearsonEducation,Quiz,10.TherequiredlogicforaPLDcanbespecifiedinanHardwareDescriptionLanguageby,a.textentryb.schematicentryc.statediagramsd.alloftheabove,
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 数字电子技术Floyd 第十版课件Chapter -03-st 数字 电子技术 Floyd 第十 课件 Chapter 03 st