基于AT89C52单片机的LED显示屏控制系统的设计外文原文和中文翻译

DesignofLEDDisplayControlSystemBasedonAT89C52SingleChipMicrocomputerInstituteofMachinery,on5February2004MauriceWilkesABSTRACT：THISpaperintroducesdisplaydesignprocessabouthardwareandsoftwarebasedonAT89C52singlechipmicrocomputer.Weuseasimpleexternalcircuittocontrolthedisplayscreen,whichsizeis32×192.Thedisplayscreenalsocandisplaythesizeofthesix32×32dotmatrixChinesecharactersbyadynamicscanmode,andcanbedividedintotwosmalldisplayscreens,whichcandisplaytwenty-fourChinesecharacterswhosesizeis16×16.Wecanmodifythecodetochangethecontentofthedisplay,subtitlescanachievescrollingfunctionandthescrollspeedcanbeadjustedaccordingtorequirements,subtitlescanalsoachievepausefunction.TheChinesecharactercodestoredinexternaldatamemory,thecapacityofdatamemoryisexpandedaccordingtotherequirementsofChinesecharacterswewanttoshow.Thisdisplayscreenhasadvantagesofsmallvolume,fewhardwareandsimplecircuitstructure.KEYWORDS:LED,ChineseCharacterDisplay,AT89C52I.INTRODUCTIONLEDdisplayhasbecomeanimportantsymbolofthecitylighting,modernizationandinformationsocietywithcontinuousimprovementandbeautificationofpeople’slivingenvironment.LEDlightscanbeseeninthelargeshoppingmalls,railwaystation,docks,undergroundstation,andavarietyofmanagementwindowandsoon.LEDbusinesshasbecomeafast-growingnewindustry,ahugemarketspaceandbrightprospects.Thetext,pictures,animationandvideoaredisplayedbyLED’slight,andcontentcanbechanged.Somecomponentsarethedisplaydevicesofthemodularstructure,andwhichusuallyconsistsofadisplaymodule,controlsystemandpowersystem.ThedisplaymoduleisconstitutedbythelatticestructurewhichconsistsofLED,andisresponsibleforlight-emittingdisplay;thescreencandisplaytext,pictures,videoandsoonbycontrolsystemwhichcancontrollightordarkofLEDinthecorrespondingregion;Powersystemisresponsiblefortransforminginputvoltageandcurrentintovoltageandcurrentwhichthescreenneeds.LEDdotmatrixdisplayextracteddisplaycharacterfontthroughPC,andsenttothemicrocontroller,thendisplayedinthedotmatrixscreen,whichmainlyusedfordisplayofindoorandoutdoorcharacters.LEDdotmatrixdisplaycanbedividedintographicdisplay,imagedisplayandvideodisplaybydisplayedcontent.Comparedwiththeimagedisplay，thecharacteristicsofgraphicdisplayisnodifferenceingraycolorwhetheritismonochromeorcolordisplay.Therefore,graphicdisplayalsofailstoreflecttherichnessofcolor,andvideodisplaycannotonlyshowexercise,clearandfull-colorimagesbutalsoshowtelevisionandcomputersignals.Althoughtherearesomedifferencesbetweenthethree,butthemostbasicprinciplesaresimilar.II.SystemOverallStructureDesignSingleChipMicrocomputer(SCM)modelswereselectedaccordingtothetarget,function,reliability,cost,accuracyandspeedofthecontrolsystem.Accordingtotheactualsituationofthesubject,thechoiceofSCMmodelsmainlyconsideredfromthefollowingtwoaspects:First,SCMhasstronganti-interferenceability;Second,SCMhasahighercost-effective.DuetoMCS-51iswidelyusedinChina,hasmoreinformationandcancompatiblewiththemoreperipheralchipstoo,inparticular,ATMELCorporation,introducedanewgenerationmicrocontrollerin2003,thatis89Sseries,anditstypicalproductswithhighperformanceandlowcostmicrocontrollerisAT89C52.AT89C52isalowvoltage,high-performanceCMOS8-bitmicrocontroller,thechipincludes8KBread-onlyprogrammemory(PEROM)whicherasecanberepeated,256byterandomaccessdatamemory(RAM),devicesadopthigh-densitynonvolatilememorytechnologytoproduce,compatiblewiththestandardMCS-51instructionsetandthe8052products,whilethechipbuilt-ingeneral-purpose8-bitcentralprocessing(CPU).Flashstorageunit,canbeappliedtothemorecomplexcontrolapplications.ThesystemwasrealizedbythecircuitrywhichismadeupofAT89C52chip,Clockcircuit,resetcircuit,columnscandrivercircuit,linedrivecircuitandthesix32×32LEDdotmatrix,theoverallstructureofLEDcharactersdisplayisshowninFig.1.Adisplayunitiscomposedofdotmatrixandtwo74HC154.Linedatasignalisdividedintotwoparts,whichisgivenbythetwo8255Arespectively,butthe8255AdataarefromtheP0portthemastercontrollerAT89C52.Thecolumnscanningsignalofeachcharacterwasgivenbythetwo74HC154,the74HC15412piecesandwasdividedintosixgroups.Theinputsignalof74HC154wasgivenbytheP1.0~P1.3ofAT89C52.Externaldatamemory6264connectedwiththeAT89C52theP0port.III.SYSTEMHARDWARECIRCUITDESIGNA.CircuitDesignofMCUControlSystemThesizeofChinesecharactersis32×32,butmicrocontrollerhas32I/Oport,andcan’tmeetdesignrequirements,sotheI/Oportmustexpand,thedataportexpansionwasimplementedbytwo8255A.ThedataportexpansionisshowninFig.2,74HC373istheaddresslatch,andlatchloweightaddress,theloweightaddresssignalsof6264providedbyit,butthehigheightaddresssignalsof6264providedbyP2.0~P2.4,Internalportof8255AwaschosenbyA0andA1.74HC139is2-4decoder,whoseinputsignalsareprovidedbyP2.6andP2.7ofSCM,andprovidedstrobefortheexternalI/Odevices,becausethesystemhasmorethanoneexternaldevice,makesurethattheycannotbegated,sothattheiraddressesistheonlyanddonotrepeat.TheclockcircuitofAT89C52composedof18,19feetfromtheclockside(XTALIandXTAL2),and12MHzcrystal,capacitorC1andC2.B.TheCircuitDesignofDisplayMemoryUnitThesizeofChinesecharactersis32×32inthedesign,eachcharactercomposed