电子专业参赛课件 数字电子技术(课件)lec13

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1、2021/9/15Chapter6FunctionsofCombinationalLogic1Lecture13Outline6-8Multiplexers(DataSelectors)6-9Demultiplexers(DataDistributors)Lecture13:MultiplexersandDemultiplexers2021/9/15Chapter6FunctionsofCombinationalLogic2KeyKnowledgeinLecture13Lecture13:MultiplexersandDemultiplex

2、ersWorkingprincipleofa4-inputmultiplexer;Multiplexerexpansion;Multiplexerusedindynamicdisplay;Usemultiplexertogeneratelogicfunctions.UsereduceddimensionK-maptogeneratelogicfunctionwithvariablesmorethanmultiplexerinputs;Workingprincipleofa2lineto4linedemultiplexer.Difficult

3、TopicsMultiplexerexpansion;ReduceddimensionK-mapmethod2021/9/15Chapter6FunctionsofCombinationalLogic3Multiplexers(DataSelectors)Lecture13:MultiplexersandDemultiplexersAmultiplexer(MUX)isadevicethatallowsdigitaldatafromseveralsourcestoberoutedontoasinglelinefortransmissiono

4、verthatlinetoacommondestination.数据选择端也称地址输入端。Itcanbeusedasaparallel-to-serialdataconverter.Outputisdeterminedbothbydataselectanddatainputs.2021/9/15Chapter6FunctionsofCombinationalLogic4MultiplexerFunctionTableLecture13:MultiplexersandDemultiplexersLogicexpressionfortheout

5、putisderivedas:2021/9/15Chapter6FunctionsofCombinationalLogic5LogicDiagramfora4-InputMultiplexerLecture13:MultiplexersandDemultiplexersRewritetheoutputexpressionofmutiplexer:Four3-inputANDgates,one4-inputORgate,twoinvertersOpenfileF06-47toverifyoperation.2021/9/15Chapter6F

6、unctionsofCombinationalLogic6MultiplexerIllustrationExampleLecture13:MultiplexersandDemultiplexersThedata-inputanddata-selectwaveformisin(a)ofthefollowingfigure,determinetheoutputwaveformY.2021/9/15Chapter6FunctionsofCombinationalLogic7结构特点：包含两个完全相同的4选1数据选择器；它们有公共的地址输入端；而数

7、据输入和输出端各自独立；地址码通过A1A0输入,S’1和S’2是附加控制端,用于控制电路工作状态和扩展功能。双4选1数据选择器74HC153Lecture13:MultiplexersandDemultiplexers2021/9/15Chapter6FunctionsofCombinationalLogic8双4选1数据选择器74HC153传输门工作原理：当A0=0时，010此时TG1和TG3导通，TG2和TG4截止。当A0=1时，101此时TG2和TG4导通，TG1和TG3截止。同理，当A1=0时TG5导通，TG6截止。当A1=1时TG

8、6导通，TG5截止。所以只有一个数据被选中。Lecture13:MultiplexersandDemultiplexers2021/9/15Chapter6Functionsof