單片機脈寬調(diào)制控制器外文文獻及翻譯

單片機脈寬調(diào)制控制器外文文獻及翻譯51 單 片 機 脈 寬 調(diào) 制 控 制 器 外 文 文 獻 及 翻 譯DesignofPWMControllerinaMCS-51CompatibleMCUYue-LiHu,WeiWangMicroelectronicResearch&DevelopmentCenter,KeyLaboratoryofAdvancedDisplayandSystemApplications(ShanghaiUniversity>,MinistryofEducationCampusP.O.B.221,149YanchangRd,Shanghai200072,ChinaE-mail:lwfree@AbstractThispaperpresentsadesignofPulse-WidthModulated(PWM>controllermoduleinaMCUbasedonMCS-51structure.Thedesigncangenerate2-channelprogrammableperiodicPWMsignals.TheseoutputPWMsignalsfromMCUcanbeusedforavarietyofapplicationsincludingmotorcontrol.Thefunctionofthedesignallowsuserstoselectindependentorcomplementaryinversiontimingrelationshipsbetween2PWMwaveforms.ThelattermodeselectionalsoincludesoptionaldeadtimefunctiontosupportdrivingH-bridgesandinverters.Therefore,userscancontroltheoutputPWMsignalsthroughsettingtheduty-cycleregisters.Afterthesuccessfulsimulationatthefrontend,practicalexperimentsmadeonaNIOSdevelopmentboardverifythedesign.1.IntroductionPWMtechnologyisakindofvoltageregulationmethodbycontrollingtheswitchfrequencyofDCpowerwithfixedvoltagetomodifythetwo-endvoltageofload.Thistechnologycanbeusedforavarietyofapplicationsincludingmotorcontrol,temperaturecontrolandpressurecontrolandsoon.InthemotorcontrolsystemshownasFig.1,throughadjustingthedutycycleofpowerswitch,thespeedofmotorcanbecontrolled.AsshowninFig.2,underthecontrolofPWMsignal,theaverageofvoltagethatcontrolsthespeedofmotorchangeswithDuty-cycle(D=t1/TinthisFigure>,thusthemotorspeedcanbeincreasedwhenmotorpowerturnon,decreasedwhenpowerturnoff.Fig.1PWMcontrolblockdiagramFig.2:TheRelationshipbetweenVoltageofArmatureandDuty-cycleTherefore,themotorspeedcanbecontrolledwithregularlyadjustingthetimeofturn-onandturn-off.Therearethreemethodscouldachievetheadjustmentofdutycycle:(1>Adjustfrequencywithfixedpulse-width.(2>Adjustbothfrequencyandpulse-width.(3>Adjustpulse-widthwithfixedfrequency.Generally,therearefourmethodstogeneratethePWMsignalsasthefollowing:(1>Generatedbythedevicecomposedofseparatelogiccomponents.Thismethodistheoriginalmethodwhichnowhasbeendiscarded.(2>Generatedbysoftware.ThismethodneedCPUtocontinuouslyoperateinstructionstocontrolI/OpinsforgeneratingPWMoutputsignals,sothatCPUcannotdoanythingother.Therefore,themethodalsohasbeendiscardedgradually.(3>GeneratedbyASIC.TheASICmakesadecreaseofCPUburdenandsteadyworkgenerallyhasseveralfunctionssuchasover-currentprotection,dead-timeadjustmentandsoon.Thenthemethodhasbeenwidelyusedinmanykindsofoccasionnow.(4>GeneratedbyPWMfunctionmoduleofMCU.ThroughembeddingPWMfunctionmoduleinMCUandinitializingthefunction六-維^論'文.網(wǎng),PWMpinsofMCUcanalsoautomaticallygeneratePWMoutsignalswithoutCPUcontrollingonlywhenneedtochangeduty-cycle.Itisthemethodthatwillbeimplementedinthispaper.Inthispaper,weproposeaPWMmoduleembeddedina8051microcontroller.ThePWMmodulecansupportPWMpulsesignalsbyinitializingthecontrolregisterandduty-cycleregisterwiththreemethodsjustmentionedabovetoadjustthedutycycleandseveraloperationmodestoaddflexibilityforuser.ThefollowingsectionexplainsthearchitectureofthePWMmoduleandthearchitecturesofbasicfunctionalblocks.Section3describestwooperationmodes.Experimentalandsimulationresultsverifyingpropersystemoperationarealsoshowninthatsection.Dependingonmodeofoperation,thePWMmodulecreatesoneormorepulse-widthmodulatedsignals,whosedutyratioscanbeindependentlyadjusted.2.ImplementationofPWMmoduleinMCU2.1OverviewofthePWMmodule六-維^論'文.網(wǎng)AblockdiagramofPWMmoduleisshowninFig.3.Itisclearlyfromthediagramthatthewholemoduleiscomposedoftwosections:PWMsignalgeneratoranddead-timegeneratorwithchannelselectlogic.ThePWMfunctioncanbestartedbytheuserthroughimplementingsomeinstructionsforinitializingthePWMmodule.Inparticular,thefollowingpowerandmotioncontrolapplicationsaresupported:?DCMotor?UninterruptablePowerSupply(UPS>Fig.3ArchitectureofPWMModuleThePWMmodulealsohasthefollowingfeatures:?TwoPWMsignaloutputswithcomplementaryorindependentoperation?Hardwaredead-timegeneratorsforcomplementarymode?DutycycleupdatesareconfigurabletobeimmediatedorsynchronizedtothePWM2.2Detailsofthearchitecture2.2.1PMWgeneratorThearchitectureofthe2-outputPWMgeneratorshowninFig.3isbasedona16-bitresolutioncounterwhichcreatesapulse-widthmodulatedsignal.Thesystemissynthesizedbyasystemclocksignalwhosefrequencycanbedividedby4timesor12timesthroughsettingthevalueofT3MforPWM0orT4MforPWM1inthespecialregisterPWMCONasshowninFig.4.ToPWM0generator,theclockto16-bitcounterwillbepre-dividedby4timesbydefaultwhenT3Missettozero.Andthe clock will bedivided by12times when T3M issetto 1.Thisisalso true forPWM1.TheotherbitsinPWMCONareexplainedindetailinT able1.161551單片機脈寬調(diào)制控制器外文文獻及翻譯第2頁Fig.4BitMappingofPWMCONb5E2RGbCAPTable 1: The Bit Definition in PWMCONBITDescriptionTF4InterruptRequestforPWM0TR4RUNbitforPWM0TF3InterruptRequestforPWM1TR3RUNbitforPWM1PSELChannelSelectinComplementaryModeCPWMModeSelectT4MClockPrescalerforPWM1T3MClockPrescalerforPWM0p1EanqFDPw2.2.2 Channel-select

logicThefollowFig.5showsthechannel-selectlogicwhichisusefulinComplementaryMode.Fromthisdiagram,itiscleartoknowthatsignalCPandCPWMcontrolthesourceofPWMHandPWML.Andthedetailsaboutthetwocontrolsignalswillbediscussedinthesection3,andthearchitectureofdead-timegeneratorwillalsobediscussed in section 3.1 for the continuity of Complementary

Mode.Fig.5DiagramofChannel-selectLogic DXDiTa9E3d3.OperationModeandSimulationResultsThedesignhastwooperationmodes:IndependentModeandComplimentaryMode.BysettingthecorrespondingbitCPWMinregisterPWMCONshowninFig.4,usercanselectoneofthetwooperationmodes.WhenCPWMissettozero,PWMmodulewillworkinIndependentMode,whereas,PWMmodulewillworkinComplimentaryMode.Inthefollowingofthissection,thetwooperationmodewillbeexplainedrespectivelyindetailandthesimulationresultsofthePWMmodulefromtheSynoposysVCSEDAplatformwhichverifythedesignwillalsobeshown.RTCrpUDGiT3.1IndependentPWMOutputModeAnIndependentPWMOutputmodeisusefulfordrivingloadssuchastheoneshowninFigure1.AparticularPWMoutputisintheIndependentOutputmodewhenthecorrespondingCPbitinthePWMCONregisterissettozero.Inthiscase,two-channelPWMoutputsareindependentofeachother.ThesignalonpinPWM0/PWMHisfromPWM0generator,andthesignalonpinPWM1/PWMLisfromPWM0generator.Theseparatecaseisachievedbythechannel-selectlogicshowninFig.6.ThePWMI/Opinsaresettoindependentmodebydefaultuponadvicereset.Thedead-timegeneratorisdisabledintheIndependentmode.ThesimulationresultisshowninFigure4asthefollowingFig.5.Tr4andtr3arerunbitstoPWM0andPWM1,respectively.Actually,fromthisdiagram,PinP1[5]/P1[4]ofMCUisusedforPWMH/PWMLornormalI/O,alternatively.Fig.6theWaveformofPWMOutputsinIndependentMode 5PCzVD7HxA3.2 Complementary PWM Output ModeTheComplementaryOutputmodeisusedtodriveinverterloadssimilartotheoneshowninFigure7.ThisinvertertopologyistypicalforDCapplications.InComplementaryOutputMode,thepairofPWMoutputscannotbeactivesimultaneously.ThePWMchannelandoutputpinpairareinternallyconfiguredthroughchannel-selectlogicasshowninFigure5.Adead-timemaybeoptionallyinsertedduringdeviceswitchingwherebothoutputsareinactiveforashortperiod.Authorizedlicenseduselimitedto:EastChinaNormalUniversity.DownloadedonJanuary11,2009at00:36fromIEEEXplore.Restrictionsapply.ProceedingsofHDP’07六-維^論'文.網(wǎng)TheComplementarymodeisselectedforPWMI/OpinpairbysettingtheappropriateCPWMbitinPWMCON.Inthiscase,PSELisineffect.PWMHandPWMLwillcomefromPWM0generatorwhenPSELissettozero,whenthesignalsfromPWM1generatorisuseless,whereasPWMHandPWMLwillcomefromPWM1generatorwhenPSELissetto1,whenthesignalsfromPWM0generatorisuseless.IntheprocessofproducingthePWMoutputsinComplementaryMode,thedead-timewillbeinsertedtobediscussedinthefollowingsection.Fig7:TypicalLoadforComplementaryPWMOutputs jLBHrnAILg3.3Dead-timeDead-timegenerationisautomaticallyenabledwhenPWMI/O

pin

Controlpair isoperatingintheComplementaryOutputmode.Becausethepoweroutputdevicescannotswitchinstantaneously,someamountoftimemustbeprovidedbetweentheturn-offeventofonePWMoutputinacomplementarypairandtheturn-oneventoftheothertransistor.The2-outputPWMmodulehasoneprogrammabledead-timewith8-bitregister.ThecomplementaryoutputpairforthePWMmodulehasan8-bitdowncounterthatisusedtoproducethedead-timeinsertion.AsshowninFigure8,thedeadtimeunithasarisingandfallingedgedetectorconnectedtoPWMsignalfromoneofPWMgenerator.ThedeadtimesisloadedintothetimeronthedetectedPWMedgeevent.Dependingonwhethertheedgeisrisingorfalling,oneofthetransitionsonthecomplementaryoutputsisdelayeduntilthetimercountsdowntozero.AtimingdiagramindicatingthedeadtimeinsertionforthepairofPWMoutputsisshowninFigure8.Fig.8Dead-timeUnitBlockDiagramConclusionsInthispaper,wehavedesignedPWMmodulebasedonan8-bitMCUcompatiblewith8051family.Thedesigncangenerate2-channelprogrammableperiodicPWMsignalswithtwooperationmode,IndependentModeandComplementaryModeinwhichdead-timewillbeinserted.ThesimulationresultsontheEDAplatform have proven itsAcknowledgmentsThe authors would like to thank Shanghai(ProjectNumber:T0103>forthefinancialsupport.

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andusefulness.Discipline Project51單片機脈寬調(diào)制控制器外文文獻及翻譯第3頁Fig.9theWaveformsofPWMOutputsinComplementaryModeReferences1.Xianghui-fangandHuyue-li,Computermeasurementandcontrol,14(7>p.942(2006>2.Huyue-liandDingqian,ConferenceonHighDensityMicrosystemDesignandPackagingandComponentFailureAnalysis,p.267(2006>Yue-LiHuandBingXiong,Proceedingsof2006Conf.onHighDensityMicrosystemDesignandPackagingandComponentFailureAnalysis(HDP’06>,China,p.278(2006>.六-維^論'文.網(wǎng)4.Yue-LiHu,Jia-LinCao,FengRanandZhi-JianLiang,Proceedingsof2004Conf.onHighDensityMicrosystemDesignandPackagingandComponentFailureAnalysis(HDP'04>,China,p.25(2004>5.JINGWei-liang,HUYue-li,CAOJia-lin.“Designof16MBAddressingSpacesinanMCUBasedontheMCS-51Structure,”The7thIEEECPMTConferenceonHighDensityMicrosystemDesignandPackagingandComponentFailureAnalysis(HDP’05>,Shanghai,China,June30-July3,(2005>,pp.509-512.6.Peterchev,A.V,JinwenXiao。Sanders,S.R,“ArchitectureandICimplementationofadigitalVRMcontroller,”PowerElectronics,IEEETransactionsonVolume18,Issue1,Part2,Jan.2003Page(s>:356–364.Smith,K.M.,Jr.。Lai,Z.。Smedley,K.M.?！癆newPWMcontrollerwithone-cycleresponse,”PowerElectronics,IEEETransactionsonVolume14,Issue1,Jan.1999Page(s>:142-150Authorizedlicenseduselimitedto:EastChinaNormalUniversity.DownloadedonJanuary11,2009at00:36fromIEEEXplore.Restrictionsapply.中文譯文：基 于 51 單 片 機 兼 容 地 脈 寬 調(diào) 制 控 制 器 地 設(shè) 計胡 越 黎 王 偉微電子研發(fā)中心,重點實驗室顯示器及系統(tǒng)應(yīng)用<上海大學(xué)）,教育部校園POB221,149延長路,上海200072,中國摘要：這篇論文描述了脈寬調(diào)制控制器模塊在微控制器中基于51單片機構(gòu)造地設(shè)計.該設(shè)計可產(chǎn)生兩條可設(shè)計地周期脈寬信號.這些從微控制器輸出地脈寬信號可以被用于多樣化地應(yīng)用軟件包括電動機控制.這種設(shè)計功能允許使用者選擇在兩個脈寬調(diào)制波形中不受約束或補充地倒置時間關(guān)系.在選擇后一個模式中包含選擇死區(qū)功能用以驅(qū)動三相H橋和逆變器.因此,使用者通過設(shè)置占空比寄存器能夠控制輸出脈寬調(diào)制信號.在成功地模擬前線末端之后,將在Nios嵌入式處理器上通過實際地實驗來證實此設(shè)計.1.緒論脈寬調(diào)制技術(shù)是一種電壓調(diào)節(jié)方法,它是通過控制直流電地轉(zhuǎn)換頻率以固定地電壓來更改負(fù)載地兩個終端電壓.這種技術(shù)可以被用于多樣化地應(yīng)用軟件包括電動機控制、溫度控制和電壓控制等.電動機控制系統(tǒng)如圖2,在脈寬調(diào)制信號地控制下,電壓地平均值通過占空比因素控制了電動機地速度,因此當(dāng)電動機電源增加,電動機速度也會增加,反之,當(dāng)電源被切斷時速度降低.圖 1 ： 脈 寬 調(diào) 制 控 制 模 塊 圖圖2：電樞電壓和占空因素地關(guān)系圖 LDAYtRyKfE因此,電動機地速度可以通過規(guī)則地調(diào)節(jié)開、關(guān)地時間來控制 .有三種方法可以達到調(diào)節(jié)周期地任務(wù)：<1）用固定地脈沖寬度來調(diào)節(jié)頻率 ,<2）調(diào)節(jié)頻率和脈沖寬度 ,<3）用固定地頻率來 調(diào) 節(jié) 脈 沖 寬 度 .一般地,有四種方法來形成脈寬信號如下： <1）通過設(shè)計地各個邏輯組成來形成 .這種是已經(jīng)被丟棄地原始額度方法 .<2）通過軟六-維^論'文.網(wǎng)件來形成.這種方法需要中央處理器不斷地操作指令用以控制輸入 /出引腳來形成脈寬輸出信號 ,以至于中央處理器不能做別地工作.因此,這種方法也已經(jīng)被逐漸地取消 .<3）通過特定用途集成電路來形成 .集成電路使得中央處理器地負(fù)荷和工作地穩(wěn)定性降低 ,它有幾點功能 ,例如,過電流保護,死區(qū)地調(diào)整等 .這種方法被廣泛地當(dāng)前地很多場合 .<4）通過微控制器地脈寬調(diào)制功能模塊來形成 .通過在微控制器中藏入脈寬調(diào)制功能模塊并初始化該功能 ,微控制器地脈寬調(diào)制引腳可以在只需要改變周期而沒有中央處理器控制地情況下自動地形成脈寬調(diào)制輸出信號 .這種方法將在本文章中得 以 實 現(xiàn) .在本文中,我們建議在脈寬調(diào)制模塊中安放一個 8051單片機.脈寬調(diào)制模塊可以通過以上提到地三種方法來調(diào)節(jié)周期和部分工作指令 ,使得控制地寄存器和周期寄存器被初始化 ,以適應(yīng)使 用 者 地 需 求 .以下地部分解釋了脈寬調(diào)制模塊地結(jié)構(gòu)和基礎(chǔ)功能塊結(jié)構(gòu) .第三部分描述了兩個 Zzz6ZB2Ltk51單片機脈寬調(diào)制控制器外文文獻及翻譯第4頁操作模塊.實驗和模擬地結(jié)果證明適當(dāng)?shù)叵到y(tǒng)操作仍然能在此部分中被顯示.根據(jù)操作地指令,脈寬調(diào)制信號模塊生成了一個或更多地脈寬已調(diào)整地信號,它地時間比率可以獨自地被調(diào)節(jié).dvzfvkwMI12.在微控制器中執(zhí)行脈寬調(diào)制模塊2.1概述脈寬調(diào)制模塊脈寬調(diào)制模塊圖如圖 3所示.從圖中可以清楚地看到整個模塊由兩部分組成：通過選擇不同地邏輯路線有脈寬信號發(fā)生器和死區(qū)發(fā)生器 .使用者通過執(zhí)行一些初始化脈寬信號地指令可以使脈寬調(diào)制功能被啟動.特別是在下列電源和運動控制應(yīng)用軟件中被支持.? 直 流 電 動 機? 不 可 中 斷 地 電 源 供 給圖3脈寬調(diào)制模塊地結(jié)構(gòu)rqyn14ZNXI脈 寬 調(diào) 制 模 塊 也 有 如 下 地 特 征 ：? 兩 個 脈 寬 輸 出 信 號 互 補 或 互 不 相 關(guān) 地 運 行? 硬 件 死 區(qū) 時 間 因 互 補 地 工 作 狀 態(tài) 而 形 成?循環(huán)更新可以直接或同步地與脈寬信號相配置EmxvxOtOco2.2體系結(jié)構(gòu)地細節(jié)2.2.1脈寬調(diào)制地形成在圖3中顯示出了兩輸出脈寬信號地形成結(jié)構(gòu) ,它是基于16位產(chǎn)生脈寬調(diào)制信號地寄存器 .該系統(tǒng)由時鐘信號合成,時鐘信號地六-維^論'文.網(wǎng)頻率通過在一個特殊寄存器PWMCON中設(shè)置T3M控制PWM0或設(shè)置T4M控制PWM1可以被分成4分頻或12分頻,如圖4所示.對于PWM0發(fā)生器,時鐘地16位寄存器將被提前分成4分頻通過將T3M預(yù)設(shè)為0.當(dāng)T3M被設(shè)為1時,時鐘信號可以被分成12分頻.這種方法對于PWM1來說也一樣.在PWMCON中地其他位將在表1中詳細說明.圖4PWMCON 地位表SixE2yXPq5表1：PWMCON地位定義位描述TF4PWM0地中斷請求TR4PWM0地啟動位TF3PWM1地中斷請求TR3PWM1地啟動位PSEL在互補方式中地途徑選擇CPWM方式選擇T4MPWM1地時鐘信號預(yù)設(shè)T3MPWM0地時鐘信號預(yù)設(shè)2.2.2途徑選擇地邏輯方式下圖5中顯示了在互補方式中有效地途徑選擇規(guī)則.從圖中,可以明了地知道CP信號和CPWM 控制了脈寬高、低電平地起因 .關(guān)于這兩個控制信號地細節(jié)將在第 3部分中被討論 ,死區(qū)時間發(fā)生器地結(jié)構(gòu)將作為互補方式地連續(xù)性在3.1節(jié)中討論.圖5途徑選擇地邏輯圖3.操作方式和模擬結(jié)果設(shè)計有兩種操作方式：