Lesson1AnalogandDigitalSignalKeywords■Analog['?n?l?g]模擬■

Output['aut,put]輸出■

Gate[get]（邏輯）門■

NOT邏輯非■

Inverter反向器■

AND邏輯與■

OR邏輯或■

Digital['did?it?l]數(shù)字的■

Binary['ba?n?r?]二進(jìn)制■

Bit[bit]（二進(jìn)制數(shù)）■

Pulse[p?ls]脈沖■

Clock[klɑk]時鐘■

Timingdiagram['ta?m??]['da??,gr?m]]時序圖

■

Data

['det?]數(shù)據(jù)■

Serial['s?r??l]串行■

Parallel['p?r?,l?l]并行■

Logic['lɑd??k]邏輯■

Input['?n,put]輸入■

工作任務(wù)：聲音是如何被記錄到電腦里的？電腦里面的聲音又是如何播放出來的？■

學(xué)習(xí)目標(biāo)：掌握模擬信號和數(shù)字信號各自的特征以及相互之間的轉(zhuǎn)換■

重點難點：模擬信號和數(shù)字信號的區(qū)分，電路中的形式，■

推薦學(xué)時：6學(xué)時工作任務(wù)：Howthesoundberecordedinthecomputer?Andhowthesoundinthecomputerbebroadcasted?1：whatisAnanalogquantity--------antemperaturelineAnanalogquantityisonehavingcontinuousvalues.Adigitalquantityisonehavingadiscretesetofvalues.Fig1-3thesoundwaveofviolinandpiano（a）sinewave(b)modulatedwave(c)dampedoscillatorywave(d)exponentialdecaywaveOtherexamplesofanalogquantitiesaretime,pressure,distance,andsound.asshowninFig1-32：whatisAndigitalquantity--------stillantemperatureline（a）positivelogic

(b)negativelogic(e)periodicdigitalsignal(c)16bitdiagram（d）nonperiodicdigitalsignal3：anexampleofanalogsystem--------aspeaker4：anexampleofanaloganddigitalsystem--------alsoaspeakerASystemUsingDigitalandAnalogMethodsThecompactdisk(CD)playerisanexampleofasysteminwhichbothdigitalandanalogcircuitsareused.ThesimplifiedblockdiagraminFigure9illustratesthebasicprinciple.Musicindigitalformisstoredonthecompactdisk.Alaserdiodeopticalsystempicksupthedigitaldatafromtherotatingdiskandtransfersittothedigital-to-analogconverter(DAC).TheDACchangesthedigitaldataintoananalogsignalthatisanelectricalreproductionoftheoriginalmusic.Thissignalisamplifiedandsenttothespeakerforyoutoenjoy.WhenthemusicwasoriginallyrecordedontheCD,aprocess,essentiallythereverseoftheonedescribedhere,usingananalog-to-digitalconverter(ADC)wasused.1、whatisaanalogs