双语教学双语教学7.doc

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1、Ch7   The Interface Technology of Single Micro ComputerlKeywords：接口（Interface）输入/输出（I/O，Input/Output）键盘（Keyboard）显示器（Display）发光二极管（LED，LightEmittingDiode）液晶显示器（LCD，LiquidCrystalDisplay）打印机（Printer）模数转换器（A/DConverter，Analogy/DigitalConverter）数模转换器（D/AConverter，

2、Digital/AnalogyConverter）lIntroduction：    TheInterfaceof8031composedofkeyboard，display，printer，A/Dconverter，D/Aconverterandsoon.    Theseperatekeyboardandthematrixkeyboardmakeupofthetwoformsofkeyboard.Figure1-TheseperatekeyboardFigure 2-The 4×4keymatrix      

3、  Akeymatrixofsizem×ncontainsmrowsandncolumns.Thesekeysarelocatedatthem×nintersectingpointsofthematrix.    TheColumnandRowlinesareconnectedwiththeI/Olines.Soweneedm＋nI/Olinestointerfacethiskeymatrix.     TheLEDhaseightsegmentsfroma，b，c，d，e，f，g，dpandtwodigitpin

4、s---com.Figure 3-LED    Accordingtothemode，LEDdisplaycanbedevidedtostaticdisplayanddynamicdisplay.Figure 4-The staticLEDdisplay    Figure 5-The dynamicLEDdisplay    ThetipicalchipofA/DConverterisADC0809，whichisa8-BituPCompatibleA/DConverterswith8-Channel，ADC08

5、09dataacquisitioncomponentisamonolithicCMOSdevicewithan8-bitanalog-to-digitalconverter,8-channelmultiplexerandmicroprocessorcompatiblecontrollogic.The8-bitA/Dconverterusessuccessiveapproximationastheconversiontechnique.Theconverterfeaturesahighimpedancechopper

6、stabilizedcomparator,a256Rvoltagedividerwithanalogswitchtreeandasuccessiveapproximationregister.The8-channelmultiplexercandirectlyaccessanyof8-single-endedanalogsignals.Thedeviceeliminatestheneedforexternalzeroandfull-scaleadjustments.Easyinterfacingtomicropro

7、cessorsisprovidedbythelatchedanddecodedmultiplexeraddressinputsandlatchedTTLTRI-STATE.outputs.ThedesignoftheADC0808,ADC0809hasbeenoptimizedbyincorporatingthemostdesirableaspectsofseveralA/Dconversiontechniques.TheADC0808,ADC0809offershighspeed,highaccuracy,min

8、imaltemperaturedependence,excellentlong-termaccuracyandrepeatability,andconsumesminimalpower.Thesefeaturesmakethisdeviceideallysuitedtoapplicationsfromprocessandmachinecontroltocon