外文出處DESIGNOFPWMCONTROLLERINAMCS51COMPATIBLEMCU附件2外文原文（復(fù)印件）DESIGNOFPWMCONTROLLERINAMCS51COMPATIBLEMCUINTRODUCTIONPWMTECHNOLOGYISAKINDOFVOLTAGEREGULATIONMETHODBYCONTROLLINGTHESWITCHFREQUENCYOFDCPOWERWITHFIXEDVOLTAGETOMODIFYTHETWOENDVOLTAGEOFLOADTHISTECHNOLOGYCANBEUSEDFORAVARIETYOFAPPLICATIONSINCLUDINGMOTORCONTROL,TEMPERATURECONTROLANDPRESSURECONTROLANDSOONINTHEMOTORCONTROLSYSTEMSHOWNASFIG1,THROUGHADJUSTINGTHEDUTYCYCLEOFPOWERSWITCH,THESPEEDOFMOTORCANBECONTROLLEDASSHOWNINFIG2,UNDERTHECONTROLOFPWMSIGNAL,THEAVERAGEOFVOLTAGETHATCONTROLSTHESPEEDOFMOTORCHANGESWITHDUTYCYCLEDT1/TINTHISFIGURE,THUSTHEMOTORSPEEDCANBEINCREASEDWHENMOTORPOWERTURNON,DECREASEDWHENPOWERTURNOFFFIG1THERELATIONSHIPBETWEENVOLTAGEOFARMATUREANDFIG2ARCHITECTUREOFPWMMODULETHEREFORE,THEMOTORSPEEDCANBECONTROLLEDWITHREGULARLYADJUSTINGTHETIMEOFTURNONANDTURNOFFTHEREARETHREEMETHODSCOULDACHIEVETHEADJUSTMENTOFDUTYCYCLE1ADJUSTFREQUENCYWITHFIXEDPULSEWIDTH2ADJUSTBOTHFREQUENCYANDPULSEWIDTH3ADJUSTPULSEWIDTHWITHFIXEDFREQUENCYGENERALLY,THEREAREFOURMETHODSTOGENERATETHEPWMSIGNALSASTHEFOLLOWING1GENERATEDBYTHEDEVICECOMPOSEDOFSEPARATELOGICCOMPONENTSTHISMETHODISTHEORIGINALMETHODWHICHNOWHASBEENDISCARDED2GENERATEDBYSOFTWARETHISMETHODNEEDCPUTOCONTINUOUSLYOPERATEINSTRUCTIONSTOCONTROLI/OPINSFORGENERATINGPWMOUTPUTSIGNALS,SOTHATCPUCANNOTDOANYTHINGOTHERTHEREFORE,THEMETHODALSOHASBEENDISCARDEDGRADUALLY3GENERATEDBYASICTHEASICMAKESADECREASEOFCPUBURDENANDSTEADYWORKGENERALLYHASSEVERALFUNCTIONSSUCHASOVERCURRENTPROTECTION,DEADTIMEADJUSTMENTANDSOONTHENTHEMETHODHASBEENWIDELYUSEDINMANYKINDSOFOCCASIONNOW4GENERATEDBYPWMFUNCTIONMODULEOFMCUTHROUGHEMBEDDINGPWMFUNCTIONMODULEINMCUANDINITIALIZINGTHEFUNCTION,PWMPINSOFMCUCANALSOAUTOMATICALLYGENERATEPWMOUTSIGNALSWITHOUTCPUCONTROLLINGONLYWHENNEEDTOCHANGEDUTYCYCLEITISTHEMETHODTHATWILLBEIMPLEMENTEDINTHISPAPERINTHISPAPER,WEPROPOSEAPWMMODULEEMBEDDEDINA8051MICROCONTROLLERTHEPWMMODULECANSUPPORTPWMPULSESIGNALSBYINITIALIZINGTHECONTROLREGISTERANDDUTYCYCLEREGISTERWITHTHREEMETHODSJUSTMENTIONEDABOVETOADJUSTTHEDUTYCYCLEANDSEVERALOPERATIONMODESTOADDFLEXIBILITYFORUSERTHEFOLLOWINGSECTIONEXPLAINSTHEARCHITECTUREOFTHEPWMMODULEANDTHEARCHITECTURESOFBASICFUNCTIONALBLOCKSSECTION3DESCRIBESTWOOPERATIONMODESEXPERIMENTALANDSIMULATIONRESULTSVERIFYINGPROPERSYSTEMOPERATIONAREALSOSHOWNINTHATSECTIONDEPENDINGONMODEOFOPERATION,THEPWMMODULECREATESONEORMOREPULSEWIDTHMODULATEDSIGNALS,WHOSEDUTYRATIOSCANBEINDEPENDENTLYADJUSTEDIMPLEMENTATIONOFPWMMODULEINMCUOVERVIEWOFTHEPWMMODULEABLOCKDIAGRAMOFPWMMODULEISSHOWNINFIG3ITISCLEARLYFROMTHEDIAGRAMTHATTHEWHOLEMODULEISCOMPOSEDOFTWOSECTIONSPWMSIGNALGENERATORANDDEADTIMEGENERATORWITHCHANNELSELECTLOGICTHEPWMFUNCTIONCANBESTARTEDBYTHEUSERTHROUGHIMPLEMENTINGSOMEINSTRUCTIONSFORINITIALIZINGTHEPWMMODULEINPARTICULAR,THEFOLLOWINGPOWERANDMOTIONCONTROLAPPLICATIONSARESUPPORTEDDCMOTORUNINTERRUPTABLELPOWERSUPPLYUPSTHEPWMMODULEALSOHASTHEFOLLOWINGFEATURESTWOPWMSIGNALOUTPUTSWITHCOMPLEMENTARYORINDEPENDENTOPERATIONHARDWAREDEADTIMEGENERATORSFORCOMPLEMENTARYMODEDUTYCYCLEUPDATESARECONFIGURABLETOBEIMMEDIATEDORSYNCHRONIZEDTOTHEPWMFIG3ARCHITECTUREOFPWMMODULEDETAILSOFTHEARCHITECTUREPMWGENERATORTHEARCHITECTUREOFTHE2OUTPUTPWMGENERATORSHOWNINFIG4ISBASEDONA16BITRESOLUTIONCOUNTERWHICHCREATESAPULSEWIDTHMODULATEDSIGNALTHESYSTEMISSYNTHESIZEDBYASYSTEMCLOCKSIGNALWHOSEFREQUENCYCANBEDIVIDEDBY4TIMESOR12TIMESTHROUGHSETTINGTHEVALUEOFT3MFORPWM0ORT4MFORPWM1INTHESPECIALREGISTERPWMCONASSHOWNINFIG4TOPWM0GENERATOR,THECLOCKTO16BITCOUNTERWILLBEPREDIVIDEDBY4TIMESBYDEFAULTWHENT3MISSETTOZEROANDTHECLOCKWILLBEDIVIDEDBY12TIMESWHENT3MISSETTO1THISISALSOTRUEFORPWM1THEOTHERBITSINPWMCONAREEXPLAINEDINDETAILINTABLE1FIG4BITMAPPINGOFPWMCONTABLE1THEBITDEFINITIONINPWMCONCHANNELSELECTLOGICTHEFOLLOWFIG5SHOWSTHECHANNELSELECTLOGICWHICHISUSEFULINCOMPLEMENTARYMODEFROMTHISDIAGRAM,ITISCLEARTOKNOWTHATSIGNALCPANDCPWMCONTROLTHESOURCEOFPWMHANDPWMLANDTHEDETAILSABOUTTHETWOCONTROLSIGNALSWILLBEDISCUSSEDINTHESECTION3,ANDTHEARCHITECTUREOFDEADTIMEGENERATORWILLALSOBEDISCUSSEDINSECTION5FORTHECONTINUITYOFCOMPLEMENTARYMODEFIG5DIAGRAMOFCHANNELSELECTLOGICOPERATIONMODEANDSIMULATIONRESULTSTHEDESIGNHASTWOOPERATIONMODESINDEPENDENTMODEANDCOMPLIMENTARYMODEBYSETTINGTHECORRESPONDINGBITCPWMINREGISTERPWMCONSHOWNINFIG6USERCANSELECTONEOFTHETWOOPERATIONMODESWHENCPWMISSETTOZERO,PWMMODULEWILLWORKININDEPENDENTMODE,WHEREAS,PWMMODULEWILLWORKINCOMPLIMENTARYMODEINTHEFOLLOWINGOFTHISSECTION,THETWOOPERATIONMODEWILLBEEXPLAINEDRESPECTIVELYINDETAILANDTHESIMULATIONRESULTSOFTHEPWMMODULEFROMTHESYNOPOSYSVCSEDAPLATFORMWHICHVERIFYTHEDESIGNWILLALSOBESHOWNINDEPENDENTPWMOUTPUTMODEANINDEPENDENTPWMOUTPUTMODEISUSEFULFORDRIVINGLOADSSUCHASTHEONESHOWNINFIGURE6APARTICULARPWMOUTPUTISINTHEINDEPENDENTOUTPUTMODEWHENTHECORRESPONDINGCPBITINTHEPWMCONREGISTERISSETTOZEROINTHISCASE,TWOCHANNELPWMOUTPUTSAREINDEPENDENTOFEACHOTHERTHESIGNALONPINPWM0/PWMHISFROMPWM0GENERATOR,ANDTHESIGNALONPINPWM1/PWMLISFROMPWM0GENERATORTHESEPARATECASEISACHIEVEDBYTHECHANNELSELECTLOGICSHOWNINFIG6THEPWMI/OPINSARESETTOINDEPENDENTMODEBYDEFAULTUPONADVICERESETTHEDEADTIMEGENERATORISDISABLEDINTHEINDEPENDENTMODETHESIMULATIONRESULTISSHOWNINFIGURE6ASTHEFOLLOWINGFIG6TR4ANDTR3ARERUNBITSTOPWM0ANDPWM1,RESPECTIVELYACTUALLY,FROMTHISDIAGRAM,PINP15/P14OFMCUISUSEDFORPWMH/PWMLORNORMALI/O,ALTERNATIVELYFIG6THEWAVEFORMOFPWMOUTPUTSININDEPENDENTMODECOMPLEMENTARYPWMOUTPUTMODETHECOMPLEMENTARYOUTPUTMODEISUSEDTODRIVEINVERTERLOADSSIMILARTOTHEONESHOWNINFIGURE7THISINVERTERTOPOLOGYISTYPICALFORDCAPPLICATIONSINCOMPLEMENTARYOUTPUTMODE,THEPAIROFPWMOUTPUTSCANNOTBEACTIVESIMULTANEOUSLYTHEPWMCHANNELANDOUTPUTPINPAIRAREINTERNALLYCONFIGUREDTHROUGHCHANNELSELECTLOGICASSHOWNINFIGURE7ADEADTIMEMAYBEOPTIONALLYINSERTEDDURINGDEVICESWITCHINGWHEREBOTHOUTPUTSAREINACTIVEFORASHORTPERIODFIG7TYPICALLOADFORCOMPLEMENTARYPWMOUTPUTSTHECOMPLEMENTARYMODEISSELECTEDFORPWMI/OPINPAIRBYSETTINGTHEAPPROPRIATECPWMBITINPWMCONINTHISCASE,PSELISINEFFECTPWMHANDPWMLWILLCOMEFROMPWM0GENERATORWHENPSELISSETTOZERO,WHENTHESIGNALSFROMPWM1GENERATORISUSELESS,WHEREASPWMHANDPWMLWILLCOMEFROMPWM1GENERATORWHENPSELISSETTO1,WHENTHESIGNALSFROMPWM0GENERATORISUSELESSINTHEPROCESSOFPRODUCINGTHEPWMOUTPUTSINCOMPLEMENTARYMODE,THEDEADTIMEWILLBEINSERTEDTOBEDISCUSSEDINTHEFOLLOWINGSECTIONDEADTIMECONTROLDEADTIMEGENERATIONISAUTOMATICALLYENABLEDWHENPWMI/OPINPAIRISOPERATINGINTHECOMPLEMENTARYOUTPUTMODEBECAUSETHEPOWEROUTPUTDEVICESCANNOTSWITCHINSTANTANEOUSLY,SOMEAMOUNTOFTIMEMUSTBEPROVIDEDBETWEENTHETURNOFFEVENTOFONEPWMOUTPUTINACOMPLEMENTARYPAIRANDTHETURNONEVENTOFTHEOTHERTRANSISTORTHE2OUTPUTPWMMODULEHASONEPROGRAMMABLEDEADTIMEWITH8BITREGISTERTHECOMPLEMENTARYOUTPUTPAIRFORTHEPWMMODULEHASAN8BITDOWNCOUNTERTHATISUSEDTOPRODUCETHEDEADTIMEINSERTIONASSHOWNINFIGURE8,THEDEADTIMEUNITHASARISINGANDFALLINGEDGEDETECTORCONNECTEDTOPWMSIGNALFROMONEOFPWMGENERATORTHEDEADTIMESISLOADEDINTOTHETIMERONTHEDETECTEDPWMEDGEEVENTDEPENDINGONWHETHERTHEEDGEISRISINGORFALLING,ONEOFTHETRANSITIONSONTHECOMPLEMENTARYOUTPUTSISDELAYEDUNTILTHETIMERCOUNTSDOWNTOZEROATIMINGDIAGRAMINDICATINGTHEDEADTIMEINSERTIONFORTHEPAIROFPWMOUTPUTSISSHOWNINFIGURE8AFIG8ADEADTIMEUNITBLOCKDIAGRAMFIG8BTHEWAVEFORMSOFPWMOUTPUTSINCOMPLEMENTARYMODECONCLUSIONSINTHISPAPER,WEHAVEDESIGNEDPWMMODULEBASEDONAN8BITMCUCOMPATIBLEWITH8051FAMILYTHEDESIGNCANGENERATE2CHANNELPROGRAMMABLEPERIODICPWMSIGNALSWITHTWOOPERATIONMODE,INDEPENDENTMODEANDCOMPLEMENTARYMODEINWHICHDEADTIMEWILLBEINSERTEDTHESIMULATIONRESULTSONTHEEDAPLATFORMHAVEPROVENITSCORRECTNESSANDUSEFULNESS附件1外文資料翻譯譯文基于C51兼容微處理器單片機的PWM控制器設(shè)計導(dǎo)言PWM技術(shù)，是一種電壓調(diào)節(jié)方法，通過控制具有固定電壓的直流電源的開關(guān)頻率來調(diào)整兩端負荷電壓。這種技術(shù)能用于各種應(yīng)用包括電機、溫度、和壓力的控制，等等。在電機系統(tǒng)中的應(yīng)用，如圖1所示，通過調(diào)整電源開關(guān)的占空比，來控制電機的速度，如圖2所示，平均電壓通過改變占空比來控制電機的速度（在圖中DT1/T）,這樣當(dāng)電機的電源打開時，它的速度加快，相反，當(dāng)電源關(guān)閉時，速度下降。圖1PWM控制框圖圖2電壓的電樞和占空比之間的關(guān)系所以，通過定期地調(diào)整時間的開通和關(guān)斷來控制電機的轉(zhuǎn)速這兒有三種方法可以完成占空比的調(diào)整（1）通過脈寬來調(diào)整頻率；（2）通過同時調(diào)整頻率和脈寬；（3）通過頻率來調(diào)整脈寬。一般情況下，有四中方法可以產(chǎn)生PWM信號，正如以下（1）由獨立邏輯元件組成的裝置產(chǎn)生，這種是原始的方法，現(xiàn)在已被淘汰；（2）通過軟件產(chǎn)生，這種方法需要CPU持續(xù)操作代碼來控制I/O口，以致于CPU不能做其他任何事。所以，這種方法也漸漸被淘汰；（3）通過ASIC產(chǎn)生，ASIC減少了CPU的負擔(dān)，并獲得了穩(wěn)定的工作，一般有幾個功能，如電流保護、死區(qū)時間調(diào)整等等；然而這種方法現(xiàn)在已被廣泛用于許多場合；（4）通過單片機的PWM功能模塊產(chǎn)生，只有當(dāng)需要改變占空比的時候CPU失控，這樣就不能產(chǎn)生PWM信號，否則通過在單片機里嵌入PWM功能模塊，并使這功能初始化，單片機的PWM口也能自動產(chǎn)生PWM信號。這種方法將在文章中講述。在本文中，我們建議在8051單片機里嵌入一個PWM模塊。該PWM模塊，通過初始化控制寄存器和寄存器的占空比，可以支持PWM脈沖信號，用剛才提到的上述三種方法調(diào)整占空比和幾個操作模式，以增加用戶彈性。以下這部分解釋PWM模塊和基本功能模塊的結(jié)構(gòu)。第三部分描述兩種操作模式。這部分還講述了實驗和仿真的結(jié)果驗證了合適的系統(tǒng)操作。通過操作模式，PWM模塊產(chǎn)生一個或更多的脈寬模塊信號，它們的比率可以自主調(diào)整。在單片機上執(zhí)行PWM模塊PWM模塊的概述PWM模塊如圖3所示，從圖中，可以很清楚得看到整個模塊有兩部分組成PWM信號產(chǎn)生器和帶有頻道選擇邏輯的死區(qū)時間產(chǎn)生器。用戶可以通過執(zhí)行一些代碼使PWM模塊初始化，從而啟動其功能。在特殊情況下，支持以下電源和運動控制應(yīng)用1直流電機2持續(xù)電源供應(yīng)PWM模塊也有以下特征1兩個PWM輸出信號以互補或獨立的方式運行2帶有互補模式的硬件死區(qū)電動機3占空比更新設(shè)置應(yīng)立刻或與PWM同步圖3PWM模塊的結(jié)構(gòu)結(jié)構(gòu)的詳細組成PWM電動機二輸出PWM電動機的結(jié)構(gòu)如圖21所示，該結(jié)構(gòu)是基于能產(chǎn)生脈寬調(diào)制信號上的16位計數(shù)器。該系統(tǒng)由四分頻或十二分頻的系統(tǒng)時鐘信號合成，時鐘信號的頻率可通過對在特殊寄存器PWMCON中的PWM0電機的T3M或PWM1電機的T4M的值進行設(shè)置而調(diào)整，如圖4所示對于PWM0電機，當(dāng)T3M設(shè)置為零時，16位計數(shù)器時鐘將被默認預(yù)分為四分頻，當(dāng)T3M設(shè)置為1時，始終將被十二分頻；PWM同樣有這種功能。在PWMCON中的其它位的定義，詳見表1圖4PWMCON的位的位置表1PWMCON的位的定義通道選擇邏輯通道選擇邏輯在互補模式中很有用，如圖5所示。從表中可以清楚得看出，信號的CP和CPWM控制PWM1和PWML的來源，這兩個控制信號的詳細情況將在第三部分講述，死區(qū)時間電機的結(jié)構(gòu)也將在一下部分的連續(xù)性互補模式中講述。圖5通道選擇邏輯表運行模式和仿真結(jié)果這種設(shè)計有兩種運行模式獨立模式和互補模式。通過在PWMCON寄存器中設(shè)置相應(yīng)的位CPWM，如圖四所示，用戶可以選擇其中一個運行模式。當(dāng)CPWM設(shè)置為0時，PWM模式將工作在獨立模式，COWM設(shè)置為1時，將工作在互補模式。在這部分兩種模式將分別被詳細講述，從VCSEDA平臺的PWM模塊的仿真結(jié)果證明這種設(shè)計。獨立PWM輸出模塊獨立PWM輸出模塊對于驅(qū)動負荷