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第1页原文Title：DEVELOPMENTANDAPPLICATIONOFSINGLECHIPMICROCOMPUTERPrincipleofMCUSingle-chipisanintegratedonasinglechipacompletecomputersystem.Eventhoughmostofhisfeaturesinasmallchip,butithasaneedtocompletethemajorityofcomputercomponents:CPUmemoryinternalandexternalbussystem,mostwillhavethecore.Atthesametimesuchasintegratedcommunicationinterfaces,timers,real-timeclockandotherperipheralequipments.Andnowthemostpowerfulsingle-chipsystemcanevenvoice,image,networking,inputandoutputcomplexsystemintegrationonasinglechip.MicrocontrollerisonlytheCPUchipdevelopedfromdedicatedprocessors.IstheearliestdesignconceptthroughtheintegrationofalargenumberofperipheralsandCPUinachip,makethecomputersystemsmaller,moreeasilyintegratedintoamoreintricateandstrictinvolumecontrolequipments．Single-chipmicrocomputerisdifferentfromthesinglemachine,however,thechipbeforewithoutdevelopment,itonlyhasthestrongfunctionofverylargescaleintegratedcircuit,ifgivingitaparticularprogram,itisaminimum,completeamicrocomputercontrolsystem,itwiththesinglemachineorpersonalcomputer(PC)thedistinctionthathavingessence,MCUapplicationbelongstothechiplevel,requirestheusertounderstandthestructureofthesingle-chipmicrocomputerandcommandsystem,andotherintegratedcircuitapplicationtechnologyandsystemneedsthetheoryanddesigntechnology,inthisparticularchipdesignapplication,sothatthechiphasthespecificfunction.DifferentMCUhavedifferenthardwareandsoftwarecharacteristics,thetechnicalfeaturesisthattheyarenotthesame,dependsontheinternalstructureofsingle-chipmicrocomputerhardwarefeatures,userswanttouseasinglechipmicrocomputer,mustknowwhethertheproductsmeettheneedoffunctionandcharacteristicparametersrequiredbytheapplicationsystem.Thetechnicalfeaturesincludethefeatures,controlandelectricalproperties,etc.,theinformationneedtogetfromthemanufacturer'stechnicalmanuals.Softwarereferstotheinstructionsystemcharacteristicsanddevelopmentsupportenvironment,instructionfeatureswhichwearefamiliarwithsingle-chipmicrocomputer第2页addressingmode,dataprocessingandlogicalapproach,input/outputcharacteristicsandtherequirementofpowersupplyandsoon.Developmentsupportofenvironmentalcompatibleincludesinstructionsandportability,supportingsoftware(includingcansupportthedevelopmentofapplicationsoftwareresources)andhardwareresources.Totakeadvantageofatypemicrocontrollertodeveloptheirownapplicationsystem,tomasteritsstructurefeaturesandtechnicalcharacteristicsisamust.Single-chipmicrocomputercontrolsystemtoreplaceprevioususeofcomplexelectroniccircuitsordigitalcircuitofcontrolsystem,cancontrolsoftwaretorealize,andcanrealizetheintellectualized,nowubiquitoussingle-chipmicrocomputercontrolcategory,suchascommunicationproducts,householdappliances,smartinstrumentation,processcontrolandspecialcontroldeviceandsoon,single-chipcomputerisfindingwiderandwiderapplicationfields.Hardwareintroduction：The8051familyofmicrocontrollersisbasedonanarchitecturewhichishighlyoptimizedforembeddedcontrolsystems.ItisusedinawidevarietyofapplicationsfrommilitaryequipmenttoautomobilestothekeyboardonyourPC.SecondonlytotheMotorola68HC11ineightbitprocessorssales,the8051familyofmicrocontrollersisavailableinawidearrayofvariationsfrommanufacturerssuchasIntel,Philips,andSiemens.Thesemanufacturershaveaddednumerousfeaturesandperipheralstothe8051suchasI2Cinterfaces,analogtodigitalconverterswatchdogtimers,andpulsewidthmodulatedoutputs.Variationsofthe8051withclockspeedsupto40MHzandvoltagerequirementsdownto1.5voltsareavailable.Thiswiderangeofpartsbasedononecoremakesthe8051familyanexcellentchoiceasthebasearchitectureforacompany'sentirelineofproductssinceitcanperformmanyfunctionsanddeveloperswillonlyhavetolearnthisoneplatform.Thebasicarchitectureconsistsofthefollowingfeatures:·aneightbitALU·32descreteI/Opins(4groupsof8)whichcanbeindividuallyaccessed·two16bittimer/counters·fullduplexUART·6interruptsourceswith2prioritylevels·128bytesofonboardRAM第3页·separate64KbyteaddressspacesforDATAandCODEmemoryOne8051processorcycleconsistsoftwelveoscillatorperiods.Eachofthetwelveoscillatorperiodsisusedforaspecialfunctionbythe8051coresuchasopcodefetchesandsamplesoftheinterruptdaisychainforpendinginterrupts.Thetimerequiredforany8051instructioncanbecomputedbydividingtheclockfrequencyby12,invertingthatresultandmultiplyingitbythenumberofprocessorcyclesrequiredbytheinstructioninquestion.Therefore,ifyouhaveasystemwhichisusingan11.059MHzclock,youcancomputethenumberofinstructionspersecondbydividingthisvalueby12.Thisgivesaninstructionfrequencyof921583instructionspersecond.Invertingthiswillprovidetheamountoftimetakenbyeachinstructioncycle(1.085microseconds).MCUapplicationsSCMnowpermeateallareasofourliveswhichisalmostdifficulttofindtracesofthefieldwithoutSCM.Missilenavigationequipment,aircraft,alltypesofinstrumentcontrol,computernetworkcommunicationsanddatatransmission,industrialautomation,real-timeprocesscontrolanddataprocessing,extensiveuseofvarioussmartICcard,civilianluxurycarsecuritysystem,videorecorder,camera,fullyautomaticwashingmachinecontrol,andprogram-controlledtoys,electronicpet,etc.