东南大学信息学院-poc实验报告.docx

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1、ComputerOrganizationandArchitectureCOURSEDESIGNAParallelOutputController------(POC)SoutheastuniversitySchoolofInformationScienceandEngineering1.Designpurposea.Thepurposeofthisprojectistodesignandsimulateaparalleloutputcontroller(POC)whichactsaninterfacebetweensystembusandprinter.T

2、heISE14.7EDAtoolisrecommendedandprovidedforsimulation.b.LearnabouttheusingofBi-directionalDataBus(BDB),anduseaparallelBi-directionalDataBustofinishthedatatransmissionbetweenCPUandPOC.2.IntroductionandTasksPOCisoneofthemostcommonI/Omodules,namelytheparalleloutputcontroller.Itplayst

3、heroleofaninterfacebetweenthecomputersystembusandtheperipheralFigure1.SystemstructurediagramAsFig.1showstheinnerconnectingofaprintertothesystembusthroughthePOC.Thecom-municationbetweenPOCandtheprinteriscontrolledbya“handshake”protocolgiveninFig.2.Figure2.Thehandshake-timingdiagram

4、betweenPOCandtheprinterThehandshakingprocessisdescribedasfollows:Whentheprinterisreadytoreceiveachar-acter,itholdsRDY=1.ThePOCmustthenholdacharacteratPD(paralleldata)portandproduceapulseattheterminalTR(transferrequest).TheprinterwillchangeRDYto0,takethecharacteratPDandholdRDYat0un

5、tilthecharacterhasbeenprinted(e.g.delay5or10ms),thensetRDYto1againwhenitisreadytoreceivethenextcharacter.ThebufferregisterBRisusedtotemporarilyholdacharactersentfromtheprocessor,whichchar-acterwillbetransferredtotheprinterlater.ThestatusregisterSRisusedfortwocontrolfunctions:①SR7s

6、ervesasareadyflagtoindicatePOCisreadyornottoreceiveanewcharacterfromtheprocessor.②SR0isusedtoenabletheinterruptrequestssentbyPOC.Ininterruptmode,IfSR0=1,thenPOCwillsendaninterruptrequestsignaltoprocessorwhenitisreadytoreceiveacharacter(i.e.,whenSR7=1).IfSR0=0,thenPOCwillnotinterru

7、pt.ThetransferofacharactertoPOCviathesystembusproceedsasfollows:Ininterruptmode,SR0isalways1.Aftersendingcharactertoprinter,POCsetstheSR7to1,sinceSR0=1,theinterruptrequestsignal(IRQ)issetto0,whichindicateaneffectiveinterruptsignaltotheprocessor.1、processorsetsthevalueofSR7&setsthe

8、valueofBR①Whentheprocessordetects