单片机课程设计英文参考文献

1、ABOUTSCMItcanbesaidacrossthetwentiethcentury,thethree"electric"era,thatis,electricalera,theelectronicage,andhasnowenteredthecomputerage.However,suchacomputer,usuallyreferstothepersonalcomputer,referredtoasPC.Itconsistsofthehost,keyboard,monitoretc.Anothertypeofcomputer,mostpeopledonotknowh

2、ow.Thiscomputeristosmarttogiveavarietyofmechanicalmicrocontroller(alsoknownasmicro-controller).Asthenamesuggests,thiscomputersystemonlyusedthesmallestoneIC,youcanperformsimpleoperationsandcontrol.Becauseofitssmallsize,usuallyhiddeninachargedmechanical"stomach"Lane.Itistheentiredevice,liket

3、hehumanbrainplaysarole,itgoeswrong,thewholedevicewasparalyzed.Now,thisMCUhasaverywidefieldofuse,suchassmartmeters,real-timeindustrialcontrol,communicationsequipment,navigationsystems,homeappliancesandsoon.Oncethemicrocontrollerwereusingavarietyofproducts,youcanservetoupgradetheeffectivenessoftheprod

4、uct,oftenintheproductnameisprecededbytheadjective-"smart",suchaswashingmachinesandsointelligent.Atpresent,sometechnicalpersonneloffactoriesorotheramateurelectronicsdeveloperstoengageinoutofcertainproducts,notthecircuitistoocomplex,thatis,functionsaretoosimpleandeasytobecopied.Thereasonmayb

5、estuckintheproductwithouttheuseofamicrocontrollerorotherprogrammablelogicdevice.SCMbasiccomponentisacentralprocessingunit(CPUinthecomputingdeviceandcontroller),read-onlymemory(usuallyexpressedasaROM),read-writememory(alsoknownasRandomAccessMemoryMRAMisusuallyexpressedasaRAM),input/outputport(alsodiv

6、idedintoparallelportandserialport,expressedasI/Oport),andsocomposed.Infactthereisalsoaclockcircuitmicrocontroller,sothatduringoperationandcontrolofthemicrocontroller,canrhythmicmanner.Inaddition,thereareso-called"breaksystem",thesystemisa"janitor"role,whenthemicrocontrollercontro

7、lobjectparametersthatneedtobeinterventiontoreachaparticularstate,canafterthis"janitor"communicatedtotheCPU,sothatCPUprioritiesoftheexternaleventstotakeappropriatecounter-measures.Electricboilertemperaturesystem1.MCUAmicrocontroller(orMCU)isacomputer-on-a-chip.Itisatypeofmicroprocessorempha

8、sizingself-sufficiencyandcost-effectiveness,incontrasttoageneral-purposemicroprocessor(thekindusedinaPC).Themajorityofcomputersystemsinusetodayareembeddedinothermachinery,suchastelephones,clocks,appliances,vehicles,andinfrastructure.Anembeddedsystemusuallyhasminimalrequirementsformemoryandprogramlen

9、gthandmayrequiresimplebutunusualinput/outputsystems.Forexample,mostembeddedsystemslackkeyboards,screens,disks,printers,orotherrecognizableI/Odevicesofapersonalcomputer.Theymaycontrolelectricmotors,relaysorvoltages,andreadswitches,variableresistorsorotherelectronicdevices.Often,theonlyI/Odevicereadab

10、lebyahumanisasinglelight-emittingdiode,andseverecostorpowerconstraintscaneveneliminatethat.Incontrasttogeneral-purposeCPUs,microcontrollersdonothaveanaddressbusoradatabus,becausetheyintegratealltheRAMandnon-volatilememoryonthesamechipastheCPU.Becausetheyneedfewerpins,thechipcanbeplacedinamuchsmaller

11、,cheaperpackage.Integratingthememoryandotherperipheralsonasinglechipandtestingthemasaunitincreasesthecostofthatchip,butoftenresultsindecreasednetcostoftheembeddedsystemasawhole.(EvenifthecostofaCPUthathasintegratedperipheralsisslightlymorethanthecostofaCPU+externalperipherals,havingfewerchipstypical

12、lyallowsasmallerandcheapercircuitboard,andreducesthelaborrequiredtoassembleandtestthecircuitboard).Thistrendleadstodesign.Amicrocontrollerisasingleintegratedcircuit,commonlywiththefollowingfeatures:centralprocessingunit-rangingfromsmallandsimple4-bitprocessorstosophisticated32-or64-bitprocessorsinpu

13、t/outputinterfacessuchasserialports(UARTs)otherserialcommunicationsinterfaceslikeI2C,SerialPeripheralInterfaceandControllerAreaNetworkforsysteminterconnectperipheralssuchastimersandwatchdogRAMfordatastorageROM,EPROM,EEPROMorFlashmemoryforprogramstorageclockgenerator-oftenanoscillatorforaquartztiming

14、crystal,resonatororRCcircuitmanyincludeanalog-to-digitalconverters.ThisintegrationdrasticallyreducesthenumberofchipsandtheamountofwiringandPCBspacethatwouldbeneededtoproduceequivalentsystemsusingseparatechipsandhaveprovedtobehighlypopularinembeddedsystemssincetheirintroductioninthe1970s.Somemicrocon

15、trollerscanaffordtouseaHarvardarchitecture:separatememorybusesforinstructionsanddata,allowingaccessestotakeplaceconcurrently.Thedecisionofwhichperipheraltointegrateisoftendifficult.TheMicrocontrollervendorsoftentradeoperatingfrequenciesandsystemdesignflexibilityagainsttime-to-marketrequirementsfromt

16、heircustomersandoveralllowersystemcost.Manufacturershavetobalancetheneedtominimizethechipsizeagainstadditionalfunctionality.Microcontrollerarchitecturesareavailablefrommanydifferentvendorsinsomanyvarietiesthateachinstructionsetarchitecturecouldrightlybelongtoacategoryoftheirown.Chiefamongthesearethe

17、8051,Z80andARMderivatives.citationneededAmicrocontroller(alsoMCUorC)isafunctionalcomputersystem-on-a-chip.Itcontainsaprocessorcore,memory,andprogrammableinput/outputperipherals.MicrocontrollersincludeanintegratedCPU,memory(asmallamountofRAM,programmemory,orboth)andperipheralscapableofinputandoutput.

18、Itemphasizeshighintegration,incontrasttoamicroprocessorwhichonlycontainsaCPU(thekindusedinaPC).Inadditiontotheusualarithmeticandlogicelementsofageneralpurposemicroprocessor,themicrocontrollerintegratesadditionalelementssuchasread-writememoryfordatastorage,read-onlymemoryforprogramstorage,Flashmemory

19、forpermanentdatastorage,peripherals,andinput/outputinterfaces.Atclockspeedsofaslittleas32KHz,microcontrollersoftenoperateatverylowspeedcomparedtomicroprocessors,butthisisadequatefortypicalapplications.Theyconsumerelativelylittlepower(milliwattsorevenmicrowatts),andwillgenerallyhavetheabilitytoretain

20、functionalitywhilewaitingforaneventsuchasabuttonpressorinterrupt.Powerconsumptionwhilesleeping(CPUclockandperipheralsdisabled)maybejustnanowatts,makingthemidealforlowpowerandlonglastingbatteryapplications.Microcontrollersareusedinautomaticallycontrolledproductsanddevices,suchasautomobileenginecontro

21、lsystems,remotecontrols,officemachines,appliances,powertools,andtoys.Byreducingthesize,cost,andpowerconsumptioncomparedtoadesignusingaseparatemicroprocessor,memory,andinput/outputdevices,microcontrollersmakeiteconomicaltoelectronicallycontrolmanymoreprocesses.Themajorityofcomputersystemsinusetodayar

22、eembeddedinothermachinery,suchasautomobiles,telephones,appliances,andperipheralsforcomputersystems.Thesearecalledembeddedsystems.Whilesomeembeddedsystemsareverysophisticated,manyhaveminimalrequirementsformemoryandprogramlength,withnooperatingsystem,andlowsoftwarecomplexity.Typicalinputandoutputdevic

23、esincludeswitches,relays,solenoids,LEDs,smallorcustomLCDdisplays,radiofrequencydevices,andsensorsfordatasuchastemperature,humidity,lightleveletc.Embeddedsystemsusuallyhavenokeyboard,screen,disks,printers,orotherrecognizableI/Odevicesofapersonalcomputer,andmaylackhumaninteractiondevicesofanykind.Itis

24、mandatorythatmicrocontrollersproviderealtimeresponsetoeventsintheembeddedsystemtheyarecontrolling.Whencertaineventsoccur,aninterruptsystemcansignaltheprocessortosuspendprocessingthecurrentinstructionsequenceandtobeginaninterruptserviceroutine(ISR).TheISRwillperformanyprocessingrequiredbasedonthesour

25、ceoftheinterruptbeforereturningtotheoriginalinstructionsequence.Possibleinterruptsourcesaredevicedependent,andoftenincludeeventssuchasaninternaltimeroverflow,completingananalogtodigitalconversion,alogiclevelchangeonaninputsuchasfromabuttonbeingpressed,anddatareceivedonacommunicationlink.Wherepowerco

26、nsumptionisimportantasinbatteryoperateddevices,interruptsmayalsowakeamicrocontrollerfromalowpowersleepstatewheretheprocessorishalteduntilrequiredtodosomethingbyaperipheralevent.Microcontrollerprogramsmustfitintheavailableon-chipprogrammemory,sinceitwouldbecostlytoprovideasystemwithexternal,expandabl

27、e,memory.Compilersandassemblylanguageareusedtoturnhigh-levellanguageprogramsintoacompactmachinecodeforstorageinthemicrocontroller'smemory.Dependingonthedevice,theprogrammemorymaybepermanent,read-onlymemorythatcanonlybeprogrammedatthefactory,orprogrammemorymaybefield-alterableflashorerasableread-

28、onlymemory.Sinceembeddedprocessorsareusuallyusedtocontroldevices,theysometimesneedtoacceptinputfromthedevicetheyarecontrolling.Thisisthepurposeoftheanalogtodigitalconverter.Sinceprocessorsarebuilttointerpretandprocessdigitaldata,i.e.1sand0s,theywon'tbeabletodoanythingwiththeanalogsignalsthatmayb

29、ebeingsenttoitbyadevice.Sotheanalogtodigitalconverterisusedtoconverttheincomingdataintoaformthattheprocessorcanrecognize.Thereisalsoadigitaltoanalogconverterthatallowstheprocessortosenddatatothedeviceitiscontrolling.Inadditiontotheconverters,manyembeddedmicroprocessorsincludeavarietyoftimersaswell.O

30、neofthemostcommontypesoftimersistheProgrammableIntervalTimer,orPITforshort.APITjustcountsdownfromsomevaluetozero.Onceitreacheszero,itsendsaninterrupttotheprocessorindicatingthatithasfinishedcounting.Thisisusefulfordevicessuchasthermostats,whichperiodicallytestthetemperaturearoundthemtoseeiftheyneedt

31、oturntheairconditioneron,theheateron,etc.TimeProcessingUnitorTPUforshort.Isessentiallyjustanothertimer,butmoresophisticated.Inadditiontocountingdown,theTPUcandetectinputevents,generateoutputevents,andotherusefuloperations.DedicatedPulseWidthModulation（PWM）blockmakesitpossiblefortheCPUtocontrolpowerc

32、onverters,resistiveloads,motors,etc.,withoutusinglotsofCPUresourcesintighttimerloops.UniversalAsynchronousReceiver/Transmitter（UART）blockmakesitpossibletoreceiveandtransmitdataoveraseriallinewithverylittleloadontheCPU.ForthosewantingethernetonecanuseanexternalchiplikeCrystalSemiconductorCS8900A,Real

33、tekRTL8019,orMicrochipENC28J60.Allofthemalloweasyinterfacingwithlowpincount.中文翻译：可以说，二十世纪跨越了三个“电”的时代，即电气时代、电子时代和现已进入的电脑时代。不过，这种电脑，通常是指个人计算机，简称PC机。它由主机、键盘、显示器等组成。还有一类计算机，大多数人却不怎么熟悉。这种计算机就是把智能赋予各种机械的单片机（亦称微控制器）。顾名思义，这种计算机的最小系统只用了一片集成电路，即可进行简单运算和控制。因为它体积小，通常都藏在被控机械的“肚子”里。它在整个装置中，起着有如人类头脑的作用，它出了毛病，整个装置就

34、瘫痪了。现在，这种单片机的使用领域已十分广泛，如智能仪表、实时工控、通讯设备、导航系统、家用电器等。各种产品一旦用上了单片机，就能起到使产品升级换代的功效，常在产品名称前冠以形容词一一“智能型”，如智能型洗衣机等。现在有些工厂的技术人员或其它业余电子开发者搞出来的某些产品，不是电路太复杂，就是功能太简单且极易被仿制。究其原因，可能就卡在产品未使用单片机或其它可编程逻辑器件上。单片机的基本组成是由中央处理器（即CPU中的运算器和控制器）、只读存贮器（通常表示为ROM、读写存贮器（又称随机存贮器通常表示为RAM、车入/输出口（又分为并行口和串行口，表示为I/O口）等等组成。实际上单片机里面还有一个

35、时钟电路，使单片机在进行运算和控制时，都能有节奏地进行。另外，还有所谓的“中断系统”，这个系统有“传达室”的作用，当单片机控制对象的参数到达某个需要加以干预的状态时，就可经此“传达室”通报给CPU使CPU艮据外部事态的轻重缓急来采取适当的应付措施。单片机即单片微型计算机，是把中央处理器、存储器、定时/计数器、输入输出接口都集成在一块集成电路芯片上的微型计算机。与应用在个人电脑中的通用型微处理器相比，它更强调自供应（不用外接硬件）和节约成本。它的最大优点是体积小，可放在仪表内部，但存储量小，输入输出接口简单，功能较低。由于其发展非常迅速，旧的单片机的定义已不能满足，所以在很多应用场合被称为范围更

36、广的微控制器，但是目前在中国大陆仍多沿用“单片机”的称呼。绝大多数现在的单片机都是基于冯诺伊曼结构的，这种结构清楚地定义了嵌入式系统所必需的四个基本部分：一个中央处理器核心，程序存储器（只读存储器或者闪存）、数据存储器（随机存储器），一个或者更多的定时/计时器，还有用来与外围设备以及扩展资源进行通信的输入/输出端口一一所有这些都被集成在单个集成电路芯片上。说单片机与通用型中央处理单元芯片不同是因为前者一般很容易配合最小型的外部支持芯片制成工作计算机。这样就可以很容易的把单片机系统植入装置内部来控制装置了。近年来为了在指令和数据上使用不同的字宽，并提高处理器流水线速度，哈佛结构在微控制器和DSP

37、也逐渐得到了广泛的应用。传统的微处理器是不允许这么做的。它要完成单片机的工作，就必须连接一些其他芯片。比如说，片上没有数据存储器，就必须要添加一些RAM勺存储芯片，虽然所添加存储器的容量很灵活，但是至少还是要添加，另外还需要添加很多连线来传递芯片之间的数据。比如，一个典型的微控制器只需要一个时钟发生器和很少的RAMROM或者EPROM,E2PROM）可BASIC语言。以在软件和晶振下工作了。同时，微控制器具有丰富的输入输出设备，像是模拟数字转换（ADC）,定时器，串口或者其他串行通讯接口（比如I2C,串行外围接口（SPI）,控制器局域网）。通常，这些继承在内部的设备可以通过特殊的指令来操作。一些现代的微控制器支持一些内建的高级编程语言，比如一个微控制器（也叫MCU是一个微型计算芯片。它包含一个处理器、一个内存（有少量的RAM,程序存储器，或两者兼而有之）和一个可编程输入/输出外设。它强调高度集成，而相比之下，一个微处理器只包含一个CPU（比如一台PC）。除了通常的算术和逻辑要素等一般用途的微处理器，微控制器还集成了更多的要素，如读写存储器的数据存储，只读存储器的存储程序，快闪记忆