数字设计期末试题参考

学院姓名学号任课老师考场教室__________选课号/座位号………密………封………线………以………内………答………题………无………效……第1页共7页电子科技大学2011-2012学年第二学期期末考试A卷课程名称：_数字逻辑设计及应用__考试形式：闭卷考试日期：2012年07月02日考试时长：_120___分钟课程成绩构成：平时30%，期中30%，实验0%，期末40%本试卷试题由___六__部分构成，共__6___页。题号一二三四五六七八九十合计得分I.Filloutyouranswersintheblanks(3’X10=30’)1.Theinputsofafull-adderareA=1,B=1,Cin=1.ThentheoutputCoutis(1).2.Ifan74x148priorityencoderhasits0,2,4,and6inputsattheactivelevel,theactiveLOWbinaryoutputis(001).3.IfanJ-Kflip-flopwithJ=1andK=1hasa10kHzclockinput,theQoutputisa(5k)Hzsquarewave.4.Asequentialcircuitwhoseoutputdependsonthestateandinputsiscalleda(Mealy)statemachine.5.IfweobservedthewaveformsofoutputQ1、Q2、Q3ofthreeflip-fl0psofacounterastheFigure1,themoduloofthecountershouldbe(6).Figure16.State/outputtableforasequentialcircuitisshownastable1.XisinputandZnisoutput.AssumethattheinitialstateisS0,iftheinputsequenceisX=01011101,theoutputsequenceshouldbe(11000100).得分CPQ1Q2Q3学院姓名学号任课老师考场教室__________选课号/座位号………密………封………线………以………内………答………题………无………效……第2页共7页7.Transition/outputtableforasequentialcircuitisshowninTable2,XisinputandYisoutput,thesequentialcircuitisamodulus(3)up/downcounter.8.A4-bitlinearfeedbackshift-register(LFSR)counterwithnoself-correctioncanhave(15)normalstates.9.Aserialsequencegeneratorbyfeedbackshiftregisters74x194isshowninFigure2,assumetheinitialstateisQ2Q1Q0=110,thefeedbackfunctionLIN=Q2/Q1/+Q2Q0/,theoutputsequenceinQ2is(110100).Figure210.Whentheinputis01000000ofan8bitDAC,thecorrespondingoutputvoltageis2V.TheoutputvoltagerangefortheDACis(0~7.97)V.II.Pleaseselecttheonlyonecorrectanswerinthefollowingquestions.(2’X5=10’)1.Ifa74x85magnitudecomparatorhasALTBOUT=AGTBOUT=0,AEQBOUT=1onitsoutputs,thecascadinginputsare(B).A)ALTBIN=0,AEQBIN=0,AGTBIN=0B)ALTBIN=0,AEQBIN=1,AGTBIN=0C)ALTBIN=1,AEQBIN=0,AGTBIN=1D)ALTBIN=1,AEQBIN=1,AGTBIN=12.Foranedge-triggeredDflip-flop,(D)iscorrect.A)achangeinthestateoftheflip-flopcanonlyataclockpulseedgeB)thestatethattheflip-flopgoestodependsontheDinputTable1State/outputtableXSn01S0S1S2S3S0/1S1/0S2/0S2/0S1/1S2/0S0/0S0/0Sn+1/ZnTable2Transition/outputtableXQ2Q1010001101110/100/001/010/001/010/000/100/0Q2*Q1*/Y得分学院姓名学号任课老师考场教室__________选课号/座位号………密………封………线………以………内………答………题………无………效……第3页共7页C)theoutputfollowstheinputateachclockpulseD)alloftheseanswers3.Anasynchronouscounterdiffersfromasynchronousin(B).A)thenumberofstatesinitssequenceB)themethodofclockingC)thetypeofflip-flopusedD)thevalueofthemodulus4.Amodulus-10Johnsoncounterrequires(C).A)tenflip-flopB)fourflip-flopC)fiveflip-flopD)twelveflip-flop5.Thecapacityofamemorythathas10bitsaddressbusandcanstore8bitsateachaddressis(B).A)1024B)8192C)80D)256III.ADLatchandaDFlip-flopareshowninFigure3.ThewaveformsofaclockCPandaninputDareshowninFigure4.AssumetheinitialstateofQis1.TrytodrawthewaveformsofQoftheDLatchandtheDFlip-flop.Ignorethedelayofthecircuit.(15’)Figure3CPDttFigure4Answer:得分学院姓名学号任课老师考场教室__________选课号/座位号………密………封………线………以………内………答………题………无………效……第4页共7页CPD锁锁锁锁锁锁QQttttInthewaveformoftheoutput,thedelayofthegatecircuithasbeentakenintoconsideration.IV.AnalyzetheclockedsynchronousstatemachineshowninFigure5.(15’)(1)Writeouttheexcitationequations,thestatetransitionequationsandtheoutputequationsofthecircuit.(5’)(2)Filloutthetransition/outputtable,anddrawthestatetransition/outputdiagram,determinewhetherthecircuitcanstartitselfautomatically.(8’)(3)DescribethelogicfunctionoftheFSM.(2’)CPDDD1Q2Q3QY1Q2Q3QFigure5Solution：（1）Theexcitationequation:D1=Q3’,D2=Q1,D3=Q1Q2Thestateequationandtheoutputequation:Q1*=D1=Q3’,Q2*=D2=Q1,Q3*=D3=Q1Q2,Y=(Q3Q1’)’=Q3’+Q1得分学院姓名学号任课老师考场教室__________选课号/座位号………密………封………线………以………内………答………题………无………效……第5页共7页（2）Thetransition/outputtable:Q3Q2Q1Q3*Q2*Q1*Y00000110010111010001101111111000000101010111000001111101Thesatetransition/outputdiagram:000/1111/1001/1011/1110/0101/1010/1100/0Sincealltheunusedstatescanentertheassertedstateafterseveralstatestransition,itcanstartitselfautomatically.(3)Thiscircuitisamould-5counter.V.Designavariablemoduluscounteronlywith74x163,whichwillbeamodule-6counterwhentheinputcontrolsignalM=1oramodule-8counterwhenM=0.Thestatesofmodule-6countershouldbe（11,12,13,14,15,0）.Thestatesofmodule-8countershouldbe(9,10,11,12,13,14,15,0）.(10’)(1)PleasewriteouttheinputequationsofLD_L,A,B,C,D.(5’)(2)Drawthecircuitlinelinkedof74x163.(5’)得分学院姓名学号任课老师考场教室__________选课号/座位号………密………封………线………以………内………答………题………无………效……第6页共7页【Solution】：theinputequations:LD_L=Q3D=A=1C=0B=MCLKCLRLDENPENTABCDQAQBQCQDRCO74x163+5VQ0Q1Q2CLOCK10MQ3VI.Writeoutthestate/outputtableforaMealymachinethatcandetectthepattern01010or01110.TheoutputZ=1whenthepatternisdetected.Yourmodelshouldalsobeabletodetectoverlappingsequences.(10’)74X163的功能表输入当前状态下一状态输出CLR_LLD_LENTENPQDQCQBQAQD*QC*QB*QA*RCO0XXXXXXX0000010XXXXXXDCBA0110XXXXXQDQCQBQA011X0XXXXQDQCQBQA011110000000101111000100100111100100011011110011010001111………….…………..01111111100001得分学院姓名学号任课老师考场教室__________选课号/座位号………密………封………线………以………内………答………题………无………效……第7页共7页StatemeaningSX01InitialstateAB,0A,0Got0BB,0C,0Got01CD,0E,0Got010DB,0F,0Got011EB,0G,0Got0101FD,1E,0Got0111GB,1A,0S*,ZVII.Thetransitionequationsandoutputequit