外文翻译原文-德克萨斯仪器MSP430单片机协议：乌尔合作模型发展的行业赞助的项目在红外数据协会实施的成功应用

SessionS1B0-7803-8552-7/04/$20.002004IEEEOctober2023,2004,Savannah,GA34thASEE/IEEEFrontiersinEducationConferenceS1B-6ImplementingIrdaOnTheMsp430:AProjectDevelopmentUnderTheUndergraduateResearch/Co-OpEducationModelManuelJimenez1,andMelisaNunez-Arzuaga21ManuelJimenez,UniversityofPuertoRicoatMayaguez,ECEDepartment,Mayagez,PR00681-9042,2MelisaNunez-Arzuaga,UniversityofPuertoRicoatMayaguez,ECEDepartment,Mayagez,PR00681-9042,402004670Abstract-Thecombinationofundergraduateresearchandco-opeducationhasbeenfoundtobeaneffectivewayofbuildingsuccessfulrelationsbetweenacademiaandindustry,asreportedbytheapplicationoftheundergraduateresearch/co-opeducationalmodel(UR/Co-op)developedattheUniversityofPuertoRicoatMayagez.ThispaperillustratesthesuccessfulapplicationoftheUR/Co-opmodelfordevelopinganindustry-sponsoredprojectintheimplementationoftheInfraredDataAssociation(IrDA)protocolontheTexasInstrumentsMSP430microcontroller.Thisprotocolhasbecomethede-factoindustrystandardforshort-rangeinfrareddataexchangebetweenportablecomputingandcommunicatingdevices.WedescribehowthestructureoftheUR/Co-opeducationalmodelwasusedinthedevelopmentoftheproject,whileprovidingsometechnicaldetailsoftheprotocol,whichhighlightthestudentlearningprocess.Thediscussionillustrateshowtheapplicationofthemodelprovidedaframeworkforasymbioticrelationwhereboththesponsoringcompanyandthestudentsinvolvedbenefitintheexercise.IndexTermsCo-opexperiences,undergraduateresearch,industrycollaboration,educationalmodel.INTRODUCTIONForoverfouryears,theElectricalandComputerEngineeringDepartmentoftheUniversityofPuertoRicoatMayagezhasheld,incollaborationwithrenownedengineeringcompanies,aprogramthatcombinestraditionalcooperativeeducation(co-op)withundergraduateresearchexperiences1.Thismodelcombinestheresultsindependentlyobtainedthrougheachmechanismtoprovidestudentswitharoundedexperiencewhereresearchoutcomes,eitherintermsoflearningexperienceorparticularprojectsareappliedtoproblemsandactivitiesintheco-oppractice.Theintegrationofthesetwomodelshasproducedseveralinterestingprojects,whichunderlinethevaluablelearningexperienceitprovidestoparticipatingstudents,whileemployersandinvolvedfacultyalsobenefit.TheexperiencereportedinthispaperillustratesoneoftheprogramprojectsthewheretheaddressedproblemwasthatofimplementingtheInfraredDataAssociation(IrDA)protocolasamemoryandpowerefficientsoftwarestackforembeddedapplications.ThetargetplatformwastheMSP430,anultra-low-powermicrocontrollerunit(MCU)developedbyTexasInstruments2.TherestofthisdocumenthasbeenorganizedtoprovideanoverviewoftheUR/co-opmodel,adescriptionoftheprojectorganization,anddetailsoftheprogramlogistics.AbriefdescriptionoftheIrDAprotocolisincludedtohighlightthestudentslearningprocess.Projectimplementationandvalidationdetailsprovideinsightintothecleversolutionsprovidedbythestudentsinthehardwareandsoftwareaspects.Finally,concludingremarkssummarizetheachievementsandoutcomesfortheinvolvedparties.UNDERGRADUATERESEARCH/CO-OPMODELOVERVIEWTheUR/Co-opmodelstructureconsistsofthreestages,namelyPre-Co-op,Co-op,andPost-Co-op,organizedasillustratedinFigure1.Inthepre-co-opstage,studentsentertheprogramasundergraduateresearchassistantstoworkinafacultyassignedproject.Inthisfirststage,facultyguidancehelpsstudentstofocusontheparticularworktobedevelopedandtogaininsightintotheresearcharea.Formostparticipants,usuallyintheirsophomoreyear,thisistheirfirstundergraduateresearchexperiencewheretheybegintodevelopself-learningskills,abilitytoperformindependentwork,andtodeepentheirtechnicalbackgroundintotheproblembeingdealtwith.Intheco-opstage,secondinthemodel,studentsparticipateofaco-opexperience.Here,moststudentscontinuetoworkintheprojectstheyinitiatedbackatschooleitheraspartoftheirregularco-opassignment,orasanactivityasidefromtheirco-opduties.Inthepostco-op,thelaststageinthemodel,studentsreturntoschoolasundergraduateresearchassistants,wheretheycompletethedocumentationoftheirprojectsanddisseminatetheoutcomesoftheirwork.Activitiesintheprogramtypicallyspanforaperiodofthreeregulartermsplussummer,sincetheco-opstageisstructuredtolastforoneregularsemesterandthesummerSessionS1B0-7803-8552-7/04/$20.002004IEEEOctober2023,2004,Savannah,GA34thASEE/IEEEFrontiersinEducationConferenceS1B-7immediatelybeforeorafterit.Thisallowsstudentstofullyadapttotheirnewenvironmentbothinthecorporateandsocialaspects,tobecomefamiliarwiththeirprojects,toapplyanddeepentheirknowledgeinthechosenfield,andtofulfillmostoftheobjectivessetforthbytheirco-opsupervisors.Moreover,theprogramstructuretakesthestudentsthrougharoundedlearningexperiencebyallowingthemtodevelopbasicresearchskillsinstageone,torefineandapplythoseskillsinstagetwo,andfinallytodeveloptheircommunicationskillthroughpresentationsandtechnicalreportsinthelaststage.Co-opGeneraleducationTechnicalbackgroundFacultymentoringCompanypresenceCo-opexperienceSideprojectUndergraduateresearchUndergraduateresearchSideprojectpresentationIndustrial&academicmentorsCo-opsupervisorPre-Co-opPost-Co-opFIGURE1UR/CO-OPMODELSTRUCTURETHEIRDASTACKPROJECTTheproblemaddressedinthisprojectwasthatofdevelopingapowerandmemoryefficient,IrDAcompliantsoftwarestack,portabletoanymemberoftheMSP430family.AlthoughseverallevelsofimplementationhavebeenreportedfortheIrDAprotocol,eitherasindependentASICsorassoftmodulesfordifferentmicrocontrollerfamilies34,portingtotheMSP430hasbeenhardlyaddressed.Besidesanearlyattempttoimplementthephysicallayeroftheprotocol5,nocompleteimplementationhasbeenfoundfortheMSP430,thatincludesdiscovery,negotiation,andexchangebetweenIrDAcompliantdevices.Moreover,therequirementsofashortcodecapableofco-existingwithotherapplicationsintheMSP430memory,ofbeingportabletoallmembersofthefamily,andabletotakeadvantageofthelowpowerfeaturesavailableinthehostMCU,madetheprojectparticularlychallenging.Theserequirementsmadeitnecessaryforthestudentstodeepentheirknowledgenotonlyinembeddedsystemsprogrammingandinterfacing,butalsoondatacommunicationsprotocols,thetechnicalspecificationsoftheIrDAprotocol(over200pagesofdetails),theMSP430architecturalandprogrammingspecifications,andthecriteriaforpowermanagementwithintheMCU.ProjectLogisticsInthefirststageofthisproject,ateamofthreestudentswasassembledtoworkontheproblem.However,shortlyafter,oneofthemwithdrewfromtheproject,leavingtwostudentstocompletethework.ThesestudentsmadeanoutstandingworkinunderstandingtheIrDAprotocol,theMCUspecifications,andprototypingthestackinClanguage.Atthispoint,thepreliminaryresultswerepresentedinalocalworkshopfortheIndustrialAffiliatesProgram6.Inthisinitialphase,thecollaborationwithindustryprovidedtechnicalinformationaboutboththeIrDAstandardandtheMSP430.Inthesecondstage,onestudentwenttothesponsoringcompanyforcontinuingtotheCo-opphase.ThisstudentcontinuedtoworkintheIrDAstackprojectforherco-op,allowinghertotakeadvantageoftheknowledgegainedinthefirststage.TheCprototypeofthestack,althoughfunctional,didnotmeetthememoryrequirementsneitherfullyexploitthelow-powermodesoftheMSP430.Therefore,animplementationinassemblylanguagewasrequired.Inaccomplishingthistask,mentoringbyanindustryadvisorwasakeyfactorforsuccessoftheproject.Thenextsectionsprovideanoverviewoftheprotocolrequirementsandthedetailsofitshardwareandsoftwareimplementations.PROJECTIMPLEMENTATIONThestructureofanIrDAstackisshowninFigure2.Thefirstthreelayersbottom-upabovetheIRAdapteraremandatory,whilethoseinthoseontopofIrLMPexceptIASareoptionalprotocolsrequiredonlyforspecificapplications.DetailsofthestructureandfunctionsofeachlayerareavailableintheIrDAprotocolspecification7.IRAdapterIrPHY(PhysicalLayer)IrLAP(LinkAccessProtocolLayer)IrLMP(LinkManagementLayer)IAS(InformationAccessServices)TTP(TinyTransportProtocol)IrCOMM,OBEX,IrLAN,IrFM,etc.FIGURE2STRUCTUREOFTHEIRDASTACKDuetothememorylimitationsimposedbytherequirementofco-existencewithotherapplications,theimplementedversionoftheprotocolwastheIrDALite8.Thisspecificationisasub-setofthefullIrDAprotocol,whichprovidestheminimumrequirementsforanydevicetobeIrDAcompliant.SomeofthestrategiesusedintheSessionS1B0-7803-8552-7/04/$20.002004IEEEOctober2023,2004,Savannah,GA34thASEE/IEEEFrontiersinEducationConferenceS1B-8developmentofthisspecificationlimittheperformanceofthestack.Forexample,speedisrestrictedto9600bpsandLAPpacketsizeislimitedto64bytes.Thefollowingsubsectionsdescribethehardwareandsoftwaredesignaspectsoftheprotocol.ThehardwarecomponentsaredesignedtocomplywiththeIrPHYspecificationsandregulations,whilethesoftwarecomponentsspanoveralltheremainingstacklayers.HardwareDesignThehardwaredesignforthisapplicationfocusesontheinterfacingoftheTIMSP430F149andSHARPGP2W004YPIrDATransceiver.Figure3showsaconnectiondiagramofthehardwarecomponents.ThestackhardwarewasprototypedaroundanMSP430F149,whichprovides60KBofflashmemoryand2KBofRAM,enoughforprogramadditions,bufferingspace,andforstoringandmanipulatingtheframessentbackandforthduringdialog.Italsohassixgeneral-purpose,8-bitI/OportsandprovideswithtwoUARTsthatenablecommunicationswithacompatibleserialportinordertodevelopapplicationsforpersonalcomputers.TESTVCCP2.5/ROSCXOUTXINRSTP2.0P2.1P2.2P1.7P1.6/TA1P1.5P1.4P1.3/TA2P1.2/TA1P1.1P1.0P2.4P2.3MSP430F149GP2W004YP327683VLEDAnodeTXRXSDGndVcc3V22u0.1uVSSFIGURE3HARDWARESCHEMATICFORMCU-IRPORTCONNECTION.TheSHARPsGP2W004YPinfraredtransceiverprovidedadherencetotheIrDAv1.0ISOspecifications9.Thispartcanbepoweredfroma3.0Vsupply,allowingdirectainterfacetotheMSP430withoutadditionalexternalcircuitry.Moreover,ittakesonlythreeMCUI/Opinsfortransmit,receive,andshutdownfunctions.SoftwareDesignAllsoftwarecomponentswerewritteninMSP430assemblylanguage.ServiceprimitivesforIrPHY,IrLAPandIrLMPwereimplementedaccordingtotheIrDALitespecifications.TinyTPandIrCOMM3-Wirewereimplementedinordertoprovidewithademonstrationoftheworkingstack.Aneighty-byteFIFObufferwasimplementedtostoreincomingandoutgoingbytesintransitthroughtheIRchannel,residinginaddress0x250hthrough0x29Fh.Table1showstheRAMmemory-mapforthedataareainthisapplication.TABLE1APPLICATIONMEMORYMAP(RAM)MSP430F149RAM(2kB)09FFh-0200hBytevariables0232h-0200h50bytesforbytevariablesWordvariables0248h-0234h11wordsforwordvariablesBufferpointerIR_BUFFER029Fh-0250hStoresbytesjustreceivedortobesentinthenextframeTheimplementationofthephysicallayerwasperformedusingTimer_A.TheapproachwastodesignaunitthatwouldbehaveasaUARTbutwouldprocessdatareceivedfromandsenttotheIRtransceiver.Thedutycycleis3/16thofapulseasspecifiedintheIrPHYdocumentation.Thetransmissionandreceptionschemesareverysimilar.TheIrLAPlayerwasimplementedasasetoffunctionsperformingallthetasksdescribedbytheprimitivesandstatetablesoftheIrDALitespecification.Thehandlingofframesbeginsbyidentifyingtheframetype.Threetypesofframesaresupported:supervisory(S),information(I)orunnumbered(U).Identificationisperformedbyparsing.Oncetheframeisidentified,programcontrolistransferredtothecorrespondinghandlingroutines.TheimplementationoftheIrLMPlayeradherestotheIrDALitespecificationsaswell.Thislayerverifiesthecorrectnessofallfieldsandensuresthatservicesrequestedbythepeerarecorrectlysupported.Italsoprovidestheframeformatthatcarriesthedatatobeexchangedbythetwocommunicatingdevices.TheIASservicesprovideatypeofyellowpagesthatstoreinformationaboutotherdevices.Italsoprovidesinformationabouttheservicessupportedbytheimplementation.TheoperationofTinyTPinvolvestheexchangeofProtocolDataUnits(TTP-PDUs)fornegotiationandflowcontrol.ThiseffectivelyaddsasingleoctetofheadertotheIrLMP-MUXdatausedtoconveyincrements(credits)tothenumberofTTP-PDUsframesthatmaybeexchangedineachdirectionusingtheunderlyingLM_Dataservice.ConnectTTP-PDUsexchangedduringconnectionestablishmentarenotregardedasrequiringorconsumingcredit.Segmentationandreassemblyarenotimplemented.SincetheIrLAPwindowsizeisequaltoone,asingleTinyTPconnectioncantakefulladvantageoftheunderlyingIrLAPwindow.Forthepurposeofthisparticularimplementation,whentheinitialTinyTPconnectionframeisidentified,acreditisissuedsothatthepeerentitycantransferitsdata.AftertheMSP430respondsandhasreceivedanRRcommandfromtheprimary,itthenissuesmorecreditforthepeerentitytocontinuetransmittingdata.SessionS1B0-7803-8552-7/04/$20.002004IEEEOctober2023,2004,Savannah,GA34thASEE/IEEEFrontiersinEducationConferenceS1B-9IrCOMMsservicesarethesameasthoseprovidedbytheIrLMPlayer.IrCOMMcallstheservicesprovidedbytheservicelayer,andthiscallpropagatesdownthestack.IrCOMMusesthedataPDUsfromIrLMPtotransmitalldataandcontrolchannelinformation.TestingtheStackGiventhenatureoftheapplication,theIrDAstackneededtobetestedforcompatibilitywiththeoperatingsystemsthatmakethemostuseofIrDA,namelyLinux,Windows,andPalmOS.InordertoassessthecompatibilitywiththeLinuxplatformthedriverIrCOMM2kwasused.Thisdriver,developedbyJanKiszka,portstheLinuxIrDAstacktoWindows10.AnotherimportantelementwasthenetworkanalyzerEthereal.Etherealcountswithplug-inswiththecapabilityofparsingIrDAframesinordertosimplifythedebuggingprocess.Thecombinationofthesetwoelementswascrucialforthetestanddebugphaseoftheproject,allowingtoverifythecompatibilitythroughtheuseoftheIrCOMM2kdriver.AnapplicationwasdevelopedusingtheIrCOMMsocketsprovidedbyWindows.ThisapplicationdidnotrequiretheuseofIrCOMM2kandfunctionsexclusivelywiththeservicesprovidedbyWindows.Inordertotestthisapplication,abufferinRAMstoredtheframesexchangedbythedevices.Thisallowedthedebuggertoseetheframesandcheckforerrors.SomeproblemswerefoundbutsolutionswereimplementedwhichallowedsimultaneousfunctionalityfortheLinuxandWindowsIrDAstacks.ThePalmOSstackwastestedinthesamewayastheWindowsstack.ThetestsweresuccessfulcorroboratingcompatibilityoftheIrDAstack.CONCLUSIONANDFUTUREWORKAprojectdevelopmentintheimplementationoftheIrDAprotocolontheMSP430hasbeenpresented,illustratingthetypesofprojectsthatcanbecarriedunderacombinedco-opundergraduateresearcheducationalmodel.Theparticularapplicationofthemodelallowedtheparticipatingstudentstohavearoundedexperiencewhichincludedstudyandbackgrounddevelopment,identifyingopportunitiestoimprovepreviousproblemapproaches,implementing,finetuning,andtestingtheirsolutions,applyingtheminacorporateenvironment,andlaterdisseminatingtheirknowledge.ThesponsoringindustrypartnerwasabletodocumenttroughtheprojectanapplicationreportonthetaskofimplementingacompleteworkingversionoftheIrDAprotocolonthetargetMCUfamily,andproducedapotentialin-jobtrainedrecruit.Thestudentsworkingintheprojectsurelygainedanexperiencethatwilllivewiththemforever.CurrentlytheyarestillatschoolcompletingtheirbachelorsdegreesinEEandCE,consideringthedevelopmentofthetestingset-uptoobtainanofficialIrDAcertificationfortheprotocolimplementation,andenjoyingthesatisfactionofhavingcompletedajobwelldone.ACKNOWLEDGMENTSTheauthorswouldliketothankMarkBucciniandMikeMitchellattheASPDivisioninTexasInstruments,Dallas,TXfortheirvaluablehelpinthedevelopmentofth