1、毕业设计（论文）外文翻译题目DESIGNOFPWMCONTROLLERINAMCS51COMPATIBLEMCUAUTHORYUELIHU,WEIWANGMICROELECTRONICRESEARCHDEVELOPMENTCENTERCAMPUSPOB221,149YANCHANGRD,SHANGHAI200072,CHINAINTRODUCTIONPWMTECHNOLOGYISAKINDOFVOLTAGEREGULATIONMETHODBYCONTROLLINGTHESWITCHFREQUENCYOFDCPOWERWITHFIXEDVOLTAGETOMODIFYTHETWOENDVOLTAG
2、EOFLOADTHISTECHNOLOGYCANBEUSEDFORAVARIETYOFAPPLICATIONSINCLUDINGMOTORCONTROL,TEMPERATURECONTROLANDPRESSURECONTROLANDSOONINTHEMOTORCONTROLSYSTEMSHOWNASFIG1,THROUGHADJUSTINGTHEDUTYCYCLEOFPOWERSWITCH,THESPEEDOFMOTORCANBECONTROLLEDASSHOWNINFIG2,UNDERTHECONTROLOFPWMSIGNAL,THEAVERAGEOFVOLTAGETHATCONTROLST
3、HESPEEDOFMOTORCHANGESWITHDUTYCYCLEDT1/TINTHISFIGURE,THUSTHEMOTORSPEEDCANBEINCREASEDWHENMOTORPOWERTURNON,DECREASEDWHENPOWERTURNOFFFIG1THERELATIONSHIPBETWEENVOLTAGEOFARMATUREANDFIG2ARCHITECTUREOFPWMMODULETHEREFORE,THEMOTORSPEEDCANBECONTROLLEDWITHREGULARLYADJUSTINGTHETIMEOFTURNONANDTURNOFFTHEREARETHREE
4、METHODSCOULDACHIEVETHEADJUSTMENTOFDUTYCYCLE1ADJUSTFREQUENCYWITHFIXEDPULSEWIDTH2ADJUSTBOTHFREQUENCYANDPULSEWIDTH3ADJUSTPULSEWIDTHWITHFIXEDFREQUENCYGENERALLY,THEREAREFOURMETHODSTOGENERATETHEPWMSIGNALSASTHEFOLLOWING1GENERATEDBYTHEDEVICECOMPOSEDOFSEPARATELOGICCOMPONENTSTHISMETHODISTHEORIGINALMETHODWHICH
5、NOWHASBEENDISCARDED2GENERATEDBYSOFTWARETHISMETHODNEEDCPUTOCONTINUOUSLYOPERATEINSTRUCTIONSTOCONTROLI/OPINSFORGENERATINGPWMOUTPUTSIGNALS,SOTHATCPUCANNOTDOANYTHINGOTHERTHEREFORE,THEMETHODALSOHASBEENDISCARDEDGRADUALLY3GENERATEDBYASICTHEASICMAKESADECREASEOFCPUBURDENANDSTEADYWORKGENERALLYHASSEVERALFUNCTIO
6、NSSUCHASOVERCURRENTPROTECTION,DEADTIMEADJUSTMENTANDSOONTHENTHEMETHODHASBEENWIDELYUSEDINMANYKINDSOFOCCASIONNOW4GENERATEDBYPWMFUNCTIONMODULEOFMCUTHROUGHEMBEDDINGPWMFUNCTIONMODULEINMCUANDINITIALIZINGTHEFUNCTION,PWMPINSOFMCUCANALSOAUTOMATICALLYGENERATEPWMOUTSIGNALSWITHOUTCPUCONTROLLINGONLYWHENNEEDTOCHAN
7、GEDUTYCYCLEITISTHEMETHODTHATWILLBEIMPLEMENTEDINTHISPAPERINTHISPAPER,WEPROPOSEAPWMMODULEEMBEDDEDINA8051MICROCONTROLLERTHEPWMMODULECANSUPPORTPWMPULSESIGNALSBYINITIALIZINGTHECONTROLREGISTERANDDUTYCYCLEREGISTERWITHTHREEMETHODSJUSTMENTIONEDABOVETOADJUSTTHEDUTYCYCLEANDSEVERALOPERATIONMODESTOADDFLEXIBILITY
8、FORUSERTHEFOLLOWINGSECTIONEXPLAINSTHEARCHITECTUREOFTHEPWMMODULEANDTHEARCHITECTURESOFBASICFUNCTIONALBLOCKSSECTION3DESCRIBESTWOOPERATIONMODESEXPERIMENTALANDSIMULATIONRESULTSVERIFYINGPROPERSYSTEMOPERATIONAREALSOSHOWNINTHATSECTIONDEPENDINGONMODEOFOPERATION,THEPWMMODULECREATESONEORMOREPULSEWIDTHMODULATED
9、SIGNALS,WHOSEDUTYRATIOSCANBEINDEPENDENTLYADJUSTEDIMPLEMENTATIONOFPWMMODULEINMCUOVERVIEWOFTHEPWMMODULEABLOCKDIAGRAMOFPWMMODULEISSHOWNINFIG3ITISCLEARLYFROMTHEDIAGRAMTHATTHEWHOLEMODULEISCOMPOSEDOFTWOSECTIONSPWMSIGNALGENERATORANDDEADTIMEGENERATORWITHCHANNELSELECTLOGICTHEPWMFUNCTIONCANBESTARTEDBYTHEUSERT
10、HROUGHIMPLEMENTINGSOMEINSTRUCTIONSFORINITIALIZINGTHEPWMMODULEINPARTICULAR,THEFOLLOWINGPOWERANDMOTIONCONTROLAPPLICATIONSARESUPPORTEDDCMOTORUNINTERRUPTABLELPOWERSUPPLYUPSTHEPWMMODULEALSOHASTHEFOLLOWINGFEATURESTWOPWMSIGNALOUTPUTSWITHCOMPLEMENTARYORINDEPENDENTOPERATIONHARDWAREDEADTIMEGENERATORSFORCOMPLE
11、MENTARYMODEDUTYCYCLEUPDATESARECONFIGURABLETOBEIMMEDIATEDORSYNCHRONIZEDTOTHEPWMFIG3ARCHITECTUREOFPWMMODULEDETAILSOFTHEARCHITECTUREPMWGENERATORTHEARCHITECTUREOFTHE2OUTPUTPWMGENERATORSHOWNINFIG4ISBASEDONA16BITRESOLUTIONCOUNTERWHICHCREATESAPULSEWIDTHMODULATEDSIGNALTHESYSTEMISSYNTHESIZEDBYASYSTEMCLOCKSIG
12、NALWHOSEFREQUENCYCANBEDIVIDEDBY4TIMESOR12TIMESTHROUGHSETTINGTHEVALUEOFT3MFORPWM0ORT4MFORPWM1INTHESPECIALREGISTERPWMCONASSHOWNINFIG4TOPWM0GENERATOR,THECLOCKTO16BITCOUNTERWILLBEPREDIVIDEDBY4TIMESBYDEFAULTWHENT3MISSETTOZEROANDTHECLOCKWILLBEDIVIDEDBY12TIMESWHENT3MISSETTO1THISISALSOTRUEFORPWM1THEOTHERBIT
13、SINPWMCONAREEXPLAINEDINDETAILINTABLE1FIG4BITMAPPINGOFPWMCONTABLE1THEBITDEFINITIONINPWMCONCHANNELSELECTLOGICTHEFOLLOWFIG5SHOWSTHECHANNELSELECTLOGICWHICHISUSEFULINCOMPLEMENTARYMODEFROMTHISDIAGRAM,ITISCLEARTOKNOWTHATSIGNALCPANDCPWMCONTROLTHESOURCEOFPWMHANDPWMLANDTHEDETAILSABOUTTHETWOCONTROLSIGNALSWILLB
14、EDISCUSSEDINTHESECTION3,ANDTHEARCHITECTUREOFDEADTIMEGENERATORWILLALSOBEDISCUSSEDINSECTION5FORTHECONTINUITYOFCOMPLEMENTARYMODEFIG5DIAGRAMOFCHANNELSELECTLOGICOPERATIONMODEANDSIMULATIONRESULTSTHEDESIGNHASTWOOPERATIONMODESINDEPENDENTMODEANDCOMPLIMENTARYMODEBYSETTINGTHECORRESPONDINGBITCPWMINREGISTERPWMCO
15、NSHOWNINFIG6USERCANSELECTONEOFTHETWOOPERATIONMODESWHENCPWMISSETTOZERO,PWMMODULEWILLWORKININDEPENDENTMODE,WHEREAS,PWMMODULEWILLWORKINCOMPLIMENTARYMODEINTHEFOLLOWINGOFTHISSECTION,THETWOOPERATIONMODEWILLBEEXPLAINEDRESPECTIVELYINDETAILANDTHESIMULATIONRESULTSOFTHEPWMMODULEFROMTHESYNOPOSYSVCSEDAPLATFORMWH
16、ICHVERIFYTHEDESIGNWILLALSOBESHOWNINDEPENDENTPWMOUTPUTMODEANINDEPENDENTPWMOUTPUTMODEISUSEFULFORDRIVINGLOADSSUCHASTHEONESHOWNINFIGURE6APARTICULARPWMOUTPUTISINTHEINDEPENDENTOUTPUTMODEWHENTHECORRESPONDINGCPBITINTHEPWMCONREGISTERISSETTOZEROINTHISCASE,TWOCHANNELPWMOUTPUTSAREINDEPENDENTOFEACHOTHERTHESIGNAL
17、ONPINPWM0/PWMHISFROMPWM0GENERATOR,ANDTHESIGNALONPINPWM1/PWMLISFROMPWM0GENERATORTHESEPARATECASEISACHIEVEDBYTHECHANNELSELECTLOGICSHOWNINFIG6THEPWMI/OPINSARESETTOINDEPENDENTMODEBYDEFAULTUPONADVICERESETTHEDEADTIMEGENERATORISDISABLEDINTHEINDEPENDENTMODETHESIMULATIONRESULTISSHOWNINFIGURE6ASTHEFOLLOWINGFIG
18、6TR4ANDTR3ARERUNBITSTOPWM0ANDPWM1,RESPECTIVELYACTUALLY,FROMTHISDIAGRAM,PINP15/P14OFMCUISUSEDFORPWMH/PWMLORNORMALI/O,ALTERNATIVELYFIG6THEWAVEFORMOFPWMOUTPUTSININDEPENDENTMODECOMPLEMENTARYPWMOUTPUTMODETHECOMPLEMENTARYOUTPUTMODEISUSEDTODRIVEINVERTERLOADSSIMILARTOTHEONESHOWNINFIGURE7THISINVERTERTOPOLOGY
19、ISTYPICALFORDCAPPLICATIONSINCOMPLEMENTARYOUTPUTMODE,THEPAIROFPWMOUTPUTSCANNOTBEACTIVESIMULTANEOUSLYTHEPWMCHANNELANDOUTPUTPINPAIRAREINTERNALLYCONFIGUREDTHROUGHCHANNELSELECTLOGICASSHOWNINFIGURE7ADEADTIMEMAYBEOPTIONALLYINSERTEDDURINGDEVICESWITCHINGWHEREBOTHOUTPUTSAREINACTIVEFORASHORTPERIODFIG7TYPICALLO
20、ADFORCOMPLEMENTARYPWMOUTPUTSTHECOMPLEMENTARYMODEISSELECTEDFORPWMI/OPINPAIRBYSETTINGTHEAPPROPRIATECPWMBITINPWMCONINTHISCASE,PSELISINEFFECTPWMHANDPWMLWILLCOMEFROMPWM0GENERATORWHENPSELISSETTOZERO,WHENTHESIGNALSFROMPWM1GENERATORISUSELESS,WHEREASPWMHANDPWMLWILLCOMEFROMPWM1GENERATORWHENPSELISSETTO1,WHENTH
21、ESIGNALSFROMPWM0GENERATORISUSELESSINTHEPROCESSOFPRODUCINGTHEPWMOUTPUTSINCOMPLEMENTARYMODE,THEDEADTIMEWILLBEINSERTEDTOBEDISCUSSEDINTHEFOLLOWINGSECTIONDEADTIMECONTROLDEADTIMEGENERATIONISAUTOMATICALLYENABLEDWHENPWMI/OPINPAIRISOPERATINGINTHECOMPLEMENTARYOUTPUTMODEBECAUSETHEPOWEROUTPUTDEVICESCANNOTSWITCH
22、INSTANTANEOUSLY,SOMEAMOUNTOFTIMEMUSTBEPROVIDEDBETWEENTHETURNOFFEVENTOFONEPWMOUTPUTINACOMPLEMENTARYPAIRANDTHETURNONEVENTOFTHEOTHERTRANSISTORTHE2OUTPUTPWMMODULEHASONEPROGRAMMABLEDEADTIMEWITH8BITREGISTERTHECOMPLEMENTARYOUTPUTPAIRFORTHEPWMMODULEHASAN8BITDOWNCOUNTERTHATISUSEDTOPRODUCETHEDEADTIMEINSERTION
23、ASSHOWNINFIGURE8,THEDEADTIMEUNITHASARISINGANDFALLINGEDGEDETECTORCONNECTEDTOPWMSIGNALFROMONEOFPWMGENERATORTHEDEADTIMESISLOADEDINTOTHETIMERONTHEDETECTEDPWMEDGEEVENTDEPENDINGONWHETHERTHEEDGEISRISINGORFALLING,ONEOFTHETRANSITIONSONTHECOMPLEMENTARYOUTPUTSISDELAYEDUNTILTHETIMERCOUNTSDOWNTOZEROATIMINGDIAGRA
24、MINDICATINGTHEDEADTIMEINSERTIONFORTHEPAIROFPWMOUTPUTSISSHOWNINFIGURE8AFIG8ADEADTIMEUNITBLOCKDIAGRAMFIG8BTHEWAVEFORMSOFPWMOUTPUTSINCOMPLEMENTARYMODECONCLUSIONSINTHISPAPER,WEHAVEDESIGNEDPWMMODULEBASEDONAN8BITMCUCOMPATIBLEWITH8051FAMILYTHEDESIGNCANGENERATE2CHANNELPROGRAMMABLEPERIODICPWMSIGNALSWITHTWOOP
25、ERATIONMODE,INDEPENDENTMODEANDCOMPLEMENTARYMODEINWHICHDEADTIMEWILLBEINSERTEDTHESIMULATIONRESULTSONTHEEDAPLATFORMHAVEPROVENITSCORRECTNESSANDUSEFULNESSREFERENCES1KIRDAC，KANBERR，WATER,NOLONGERAPLENTIFULRESOURCE,SHOULDBEUSEDSPARINGLYINIRRIGATEDAGRICULTUREMCROPYIELDRESPONSETODEFICITIRRIGATION,19991202FRI
26、ELINGHAUS,M,THEDEVELOPMENTOFSPRINKLERIRRIGATIONTECHNIQUEWITHCLEANWATERINGERMANYMIRRIGATIONUNDERCONDITIONSOFWATERSCARCITY,1999169183译文题目设计通过MCS51单片机兼容的PWM控制器作者YUELIHU,WEIWA单片机研究与开发中心CAMPUSPOB221,149YANCHANGRD,SHANGHAI200072,CHINA导言PWM技术，是一种电压调节方法，通过控制具有固定电压的直流电源的开关频率来调整两端负荷电压。这种技术能用于各种应用包括电机、温度、和压力的控
27、制，等等。在电机系统中的应用，如图1所示，通过调整电源开关的占空比，来控制电机的速度，如图2所示，平均电压通过改变占空比来控制电机的速度（在图中DT1/T）,这样当电机的电源打开时，它的速度加快，相反，当电源关闭时，速度下降。图1PWM控制框图图2电压的电枢和占空比之间的关系所以，通过定期地调整时间的开通和关断来控制电机的转速这儿有三种方法可以完成占空比的调整（1）通过脉宽来调整频率；（2）通过同时调整频率和脉宽；（3）通过频率来调整脉宽。一般情况下，有四中方法可以产生PWM信号，正如以下（1）由独立逻辑元件组成的装置产生，这种是原始的方法，现在已被淘汰；（2）通过软件产生，这种方法需要CPU
28、持续操作代码来控制I/O口，以致于CPU不能做其他任何事。所以，这种方法也渐渐被淘汰；（3）通过ASIC产生，ASIC减少了CPU的负担，并获得了稳定的工作，一般有几个功能，如电流保护、死区时间调整等等；然而这种方法现在已被广泛用于许多场合；（4）通过单片机的PWM功能模块产生，只有当需要改变占空比的时候CPU失控，这样就不能产生PWM信号，否则通过在单片机里嵌入PWM功能模块，并使这功能初始化，单片机的PWM口也能自动产生PWM信号。这种方法将在文章中讲述。在本文中，我们建议在8051单片机里嵌入一个PWM模块。该PWM模块，通过初始化控制寄存器和寄存器的占空比，可以支持PWM脉冲信号，用刚
29、才提到的上述三种方法调整占空比和几个操作模式，以增加用户弹性。以下这部分解释PWM模块和基本功能模块的结构。第三部分描述两种操作模式。这部分还讲述了实验和仿真的结果验证了合适的系统操作。通过操作模式，PWM模块产生一个或更多的脉宽模块信号，它们的比率可以自主调整。在单片机上执行PWM模块PWM模块的概述PWM模块如图3所示，从图中，可以很清楚得看到整个模块有两部分组成PWM信号产生器和带有频道选择逻辑的死区时间产生器。用户可以通过执行一些代码使PWM模块初始化，从而启动其功能。在特殊情况下，支持以下电源和运动控制应用1直流电机2持续电源供应PWM模块也有以下特征1两个PWM输出信号以互补或独立
30、的方式运行2带有互补模式的硬件死区电动机3占空比更新设置应立刻或与PWM同步图3PWM模块的结构结构的详细组成PWM电动机二输出PWM电动机的结构如图21所示，该结构是基于能产生脉宽调制信号上的16位计数器。该系统由四分频或十二分频的系统时钟信号合成，时钟信号的频率可通过对在特殊寄存器PWMCON中的PWM0电机的T3M或PWM1电机的T4M的值进行设置而调整，如图4所示对于PWM0电机，当T3M设置为零时，16位计数器时钟将被默认预分为四分频，当T3M设置为1时，始终将被十二分频；PWM同样有这种功能。在PWMCON中的其它位的定义，详见表1图4PWMCON的位的位置表1PWMCON的位的定
31、义通道选择逻辑通道选择逻辑在互补模式中很有用，如图5所示。从表中可以清楚得看出，信号的CP和CPWM控制PWM1和PWML的来源，这两个控制信号的详细情况将在第三部分讲述，死区时间电机的结构也将在一下部分的连续性互补模式中讲述。图5通道选择逻辑表运行模式和仿真结果这种设计有两种运行模式独立模式和互补模式。通过在PWMCON寄存器中设置相应的位CPWM，如图四所示，用户可以选择其中一个运行模式。当CPWM设置为0时，PWM模式将工作在独立模式，COWM设置为1时，将工作在互补模式。在这部分两种模式将分别被详细讲述，从VCSEDA平台的PWM模块的仿真结果证明这种设计。独立PWM输出模块独立PWM
32、输出模块对于驱动负荷很有用，如图6所示。当在PWMCON寄存器中相应的CP位设置为0，特殊的PWM输出模块是在独立的输出模式里。在这种情况下，PWM的两种通道输出是相互独立的。在PWM0/PWML口的信号是从PWM0电机产生的。通道选择逻辑完成单独情况，如图6所示。PWMI/O口通过默认意见复位设置为独立模式，但死区时间电机不能在独立模式下工作。仿真结果如图6所示。TR4和TR3分别与PWM0和PWM1相连，实际上，从图看，单片机的P15/P4口被用做PWMH/PWML或是一般的I/O口。图6独立模式下的PWM波形互补PWM输出模式互补输出模式可以用于驱动逆变器负载，如图7所示。这种逆变器拓扑
33、学是典型的直流装置。在互补输出模式，PWM的两个输出不能同时用。PWM通道和输出口都是通过通道选择逻辑内部配置的，如图7所示。死区时间是在两端输出的开关装置没有工作的短时期时可以选择插入的。图7PWM互补输出的典型电路PWMI/O口通过在PWMCON中设置适当的CPWM位选择互补模式，在这种情况下，PSWL是有效果的。当PSEL设置为0时，PWMH和PWML将来自PWM0电机，这时来自PWM1电机的信号是没用的，而当PSEL设置为1时，PWMH和PWML将来自PWM1电机，这时来自PWM0电机的信号是没用的。在互补模式时产生PWM输出信号的过程中，死区时间将被插入在以下这部分讲述。死区时间控制
34、当PWMI/O口在互补输出模式运行时，死区时间是自动启用生成的，因为电源输出装置不能瞬间开关，在互补对模式下，一个PWM输出的关闭与其它晶体管打开之间要一定的时间，2输出的PWM模块有一个带有8位寄存器的可编程死区时间。PWM模块的互补输出对已有一个用于产生死区时间插入的8位计数器。死区时间单元有一个上升沿和下降沿探测器，而这个探测器与PWM电机产生的PWM信号连接。当到达PWM边沿时，死区时间被载入计时器，根据是否是上升沿或下降沿，在互补输出端口上的其中一个过度被延迟，直到计数器降为0。PWM输出对的死区时间表，如图8A所示图8A死区时间单元模块图图8B互补模式的PWM输出波形总结本文，我们设计了基于8位兼容8051单片机的PWM模块，这种设计能产生2通道带有两种运行模式的可编程周期PWM信号，即可插入死区时间的独立模式和互补模式。这种在EDA平台的仿真结果已证明了它的和谐性和有用性。
