基于ARM的音频播放器设计外文文献

1-4244-0216-6/06/$20.00©2006IEEEDesignandImplementationofaTable-basedGUIforMP3PlayersYing-WenBaiandFu-EnTsaiAbstract—InadditiontothetwopresentmethodsforsystemcontrolprogrammingmechanismofMP3players,duetothemarketingcompetitionofMP3players,thereisaneedforafastGUIdesignforvariouscustomers.ThefirstmethodstoresonlythebootcodeintheROMofthecontroller.ThemainprogramisstoredintheNANDflashwhichincludestheinitializingprogramcode.Aslongastheinitializationiscompleted,theprogramcodewillbeloadedintothesystemfromtheNANDflash.TheadvantagesofthismethodarethatthemainprogramcanupdatetheGUIanytimeandprovidemoreflexibility.However,thechipareawillincreaseduetotheneedofRAMforstoringtheprogram.ThesecondmethodistostorethemainprogramintotheROMofthecontroller,bywhichthisdesigndoesnotneedtouseanextraRAMinordertosavethechiparea.However,whenthemainprogramisoncestoredintotheROM,thefunctionoftheMP3playercannotchangeanymore.Inthispaper,weproposeatablebasedGUIdesignwhichprovidesafastwaytoobtainthedifferentprogrammableGUIfromtheprestoredNANDflash.AcoupleoftablesareusedtosupportvariouscustomerGUIs,suchas,acommandtableforthebasicoperationalprocedure,adisplaytableforthebasicdisplaycomponents,amanualtableforthebasicfunctionoftheMP3playerandakeytableforthekeyfunctionusedwiththeMP3operation.ThesetablescanbeprestoredintheNANDflashmodule.WhenusersturnontheMP3player,themainprogramoftheMP3playerwillloadinthecustomerrequiredtables.Hence,byusingourdesign,adifferentsetofthesetableswillprovideuserswithdifferentGUIsevenifthesamechipsetinthehardwaremodulesisutilized1.IndexTerms—Table-basedGUI,MP3Player.I.INTRODUCTIONAccordingtomarketingreports,theportablecompressedaudio(MP3)playermarketcontinuestosurge,ledbytheportableflashplayercategorywhichisexpectedtoincreasefrom26.4millionunitsshippedworldwidein2004tonearly124millionunitsin2009[1].Hence,alotofcompaniesareactivelyinvolvedintheMP3industry,butnowthedifferenceinmakingproductsisbecomingmoreandmoreimportant.Theproductsdifferintheir“functions”,“appearance”and“userinterface”HowcanaMP3player1Ying-WenBaiiswiththeDepartmentofElectronicEngineering,FuJenCatholicUniversity,Taipei,Taiwan,242,R.O.C.(e-mail:[e-mail])Fu-EnTsaiisagraduatestudentofFuJenCatholicUniversity,Taipei,Taiwan,242,R.O.C.(e-mail:[e-mail])appeartohaveadifferentuserinterface?Howcananengineerquicklyandefficientlyreachthedifferentuserinterfaces?Usually,aMP3playerdesignofreachingdifferentuserinterfacescanbeclassifiedintothreemethodsasshowninFig.1.ThefirstmethodusesaninsideROMpreservesbootcodeincontrollingthechip,andleavesthemainprograminNANDFlash.Theprogramcontrolsandonlypreservesandinitializesnecessarytheprocedureyardsystematicallywithinthechip.TheprocedureisdividedintowhenitwillreachtheNANDFlash.Afterinitializingandfinishing,theblockiswrittenintothesystem.Themajoradvantageofthismethoditisupdatetheuserinterfaceatanytimeforthemainprogram.Also,thefunctionelasticityisverygreat.ButtheshortcomingistheprogramneedstouseRAMtopreservetheprocedurewithinthechip,resultinginanincreasedchiparea[2].Thesecondmethodistoplantthewholeprocedureintoacontrollerinthemainchip,whichdoesnotneedtouseRAMtopreservetheprocedureexternally,thussavingthechipareaastheratiobetweentheRAMandROMis8.However,theshortcomingisplantingthecontrolcodeintotheROMchip,whichisunabletoupgradeagain.Thatistosaythatthismethodcanonlysupportacertainspecificfunction,namelypicturesorabutton.Functionsshownareallunabletobemodifiedagainafterchipfabrication[3].Method1MP3controllerBootROMNANDFlashMainprogram+FontMethod2MP3controllerMainprogramNANDFlashFontMethod3MP3controllerMainprogramNANDFlashSpecializetable+FontFig.1.ThethreedesignmethodsofMP3playersforrealizingtheGUI.Thispaperproposesathirdmethod,whichhastheadvantagesofacombinationofthetwopresentmethods.ThismethodregardstheprocedurestructureoftheROMbaseastheprerequisite,andutilizestheNANDFlashtopasstheUSBrenewablecharacteristicatanytime,sothedesignercanleavetheinformationcontentasapictureshowninNANDFlash,whichcanmakespecificdisplayinformationbyusingNANDFlashafterthesystemstartsthemachine,whichthenreconfiguresintoanewoperationinterface.Thus,evenbyplantingthecontrolprocedureintoacontrollerchip,onecanstillloadthedifferentlydesignedGUItablesfromtheNANDFlash.Hence,thedesignercanprovideadifferentdisplayinterface,thedifferentbuttonassignmentsandfunctions,andalsoofferthemultipleGUIsofaMP3playerevenusingthesamechipset[4,5].Section2introducesthedatastructureandtheoperatingdetailofthecommandtable,thedisplaytable,thekeytableandthemenutable.Inaddition,thesefivetablesprovidethebasicguidelinesofthesystemoperationincludingthekindofkeyfunctionsandhowtochangethedisplay.Section3showstheimplementationresultswhichincludethedifferentGUIs,thetablesizesandtheaccessingspeedforourdesign.Section4drawsaconclusion.II.DESIGNANDIMPLEMENTATIONInordertoprovideauserinterfacewithdifferentwaysandcharacteristics,thebuttonassignmentsandthebuttonfunctions,wecreateamechanismbasedontheTableinterpretationtocreatevariouskindsofuserinterfacesandtosetthefunctiondefinitionsofthe