外文翻译-STC89C52 数据手册

附录B：外文文献及译文STC89C52DateSheetDescriptionTheSTC89C52isalow-power，high-performanceCMOS8-bitmicrocontrollerwith8Kbytesofin-systemprogrammableFlashmemory.Thedeviceis manufacturedusingAtmel’shigh-densitynonvolatilememorytechnologyandiscompatiblewiththeindustry-standard80C51instructionsetandpinout.Theon-chipFlashallowsprogrammemorytobereprogrammedin-systemorbyaconventionalnonvolatilememory programmer. By combining a versatile 8-bit CPU with programmableFlashonamonolithicchip，theAtmelSTC89C52isapowerfulmicrocontrollerwhichprovidesahighly-flexibleandcost-effectivesolutiontomanyembeddedcontrolapplications.TheSTC89C52providesthefollowingstandardfeatures:8KbytesofFlash，256bytesofRAM，32I/Olines，Watchdogtimer，twodatapointers，three16-bittimer/counters，asix-vectortwo-levelinterruptarchitecture，afullduplexserialon-chiposcillator，andclockcircuitry.Inaddition，theSTC89C52isdesignedwithstaticlogicforoperationdowntozerofrequencyandsupportstwosoftwareselectablepowersavingmodes.TheIdleModestopstheCPUwhileallowingtheRAM，timer/counters，serialport，andinterruptsystemtocontinuefunctioning.ThePower-downmodesavestheRAMcontentsbutfreezestheoscillator，disablingallotherchipfunctionsuntilthenextinterruptorhardwarereset.VCCSupplyvoltage.GNDGround.Port0Port0isan8-bitopendrainbidirectionalI/Oport.Asanoutputport ，eachpincansinkeightTTLinputs.When1sarewrittentoport0pins ，thepinscanbeusedashighimpedanceinputs.Port0canalsobeconfiguredtobethemultiplexedloworderaddress/databusduringaccessestoexternalprogramanddatamemory.InthismodeP0hasinternalpullups.Port0alsoreceivesthecodebytesduringFlashprogrammingandoutputsthecodebytesduringprogramverification.Externalpullupsarerequiredduringprogramverification.Port1Port1isan8-bitbidirectionalI/Oportwithinternalpullups.ThePort1outputbufferscansink/sourcefourTTLinputs.When1sarewrittentoPort1pins，theyarehighbytheinternalpullupsandcanbeusedasinputs.Asinputs，Port1pinsthatexternallybeingpulledlowwillsourcecurrent(IIL)becauseoftheinternalpullups.Inaddition，P1.0andP1.1canbeconfiguredtobethetimer/counter2externalinput(P1.0/T2)andthetimer/counter2triggerinput(P1.1/T2EX)，Port1alsoreceivesthelow-orderaddressbytesduringFlashprogrammingandverificationPort2Port2isan8-bitbidirectionalI/Oportwithinternalpullups.ThePort2outputbufferscansink/sourcefourTTLinputs.When1sarewrittentoPort2pins，theyarepulledhighbytheinternalpullupsandcanbeusedasinputs.Port2emitsthehigh-orderaddressbyteduringfetchesfromexternalprogrammemoryandduringaccessestoexternaldatamemorythatuse16-bitaddresses(MOVX@DPTR).Inthisapplication，Port2usesstronginternalpull-upswhenemitting1s.Duringaccessestoexternaldatamemorythatuse8-bitaddresses(MOVX@RI)，Port2emitsthecontentsoftheP2SpecialFunctionRegister.Port2alsoreceivesthehigh-orderaddressbitsandsomecontrolsignalsduringFlashprogrammingandverification.Port3Port3isan8-bitbidirectionalI/Oportwithinternalpullups.ThePort3outputbufferscansink/sourcefourTTLinputs.When1sarewrittentoPort3pins，theyarehighbytheinternalpullupsandcanbeusedasinputs.Asinputs，Port3pinsthatexternallybeingpulledlowwillsource current(IIL)becauseofthepullups. Port3alsoservesthefunctionsofvariousspecialfeaturesoftheSTC89C52，asshowninthefollowingtable.Port3alsoreceivessomecontrolsignalsforFlashprogrammingandverification.RSTResetinput.Ahighonthispinfortwomachinecycleswhiletheoscillatorisrunningresetsthedevice.ThispindrivesHighfor96oscillatorperiodsaftertheWatchdogtimesout.TheDISRTObitinSFRAUXR(address8EH)canbeusedtodisablethisfeature.InthedefaultstateofbitDISRTO，theRESETHIGHoutfeatureisALE/PROGAddressLatchEnable(ALE)isanoutputpulseforlatchingthelowbyteoftheaddressduringaccessestoexternalmemory.Thispinisalsotheprogrampulseinput(PROG)duringFlashprogramming.Innormaloperation，ALEisemittedatconstantrateof1/6theoscillatorfrequencyandmaybeusedforexternaltimingorclockingpurposes.Ifdesired，ALEoperationcanbedisabledbysettingbit0ofSFRlocation8EH.Withthebitset，ALEisactiveonlyduringaMOVXorMOVCinstruction.Otherwise，thepinisweaklypulledhigh.SettingtheALE-disablebitnoeffectifthemicrocontrollerisinexternalexecutionmode.PSENProgramStoreEnable(PSEN)isthereadstrobetoexternalprogrammemory.WhentheSTC89C52isexecutingcodefromexternalprogrammemory，PSENisactivatedtwiceeachmachinecycle，exceptthattwoPSENactivationsareskippedduringaccesstoexternaldatamemory.EA/VPPExternalAccessEnable.EAmustbestrappedtoGNDinordertoenablethedevicetofetchcodefromexternalprogrammemorylocationsstartingat0000HuptoFFFFH.Note，however，thatiflockbit1isprogrammed，EAwillbeinternallylatchedreset.EAshouldbestrappedtoVCCforinternalprogramexecutions.Thispinalsoreceivesthe12-voltprogrammingenablevoltage(VPP)duringFlashprogramming.XTAL1Inputtotheinvertingoscillatoramplifierandinputtotheinternalclockoperatingcircuit.XTAL2Outputfromtheinvertingoscillatoramplifier.译文：STC89C52数据手册功能特性描述STC89C52是一种低功耗、高性能CMOS88K在系统可Flash80C51产品指令和引脚完全兼容。片上Flash8CPUSTC89C52为众多嵌入式控制应用系统提供高灵活、超有效的解决方案。STC89C528kI/O口16位定时器/622种软件可选择节电模式。空闲模式下，CPU停止工作，RAM、定时器/计数器、串口、中断继续工作。掉电保护方式下，RAM内止。VCC:电源GND:地P0口是一个8位漏极开路的双向8个TTL逻辑电平。对P0端口写“1”时，引脚用作高阻抗输入。当访问外部程序和数据存8位地址/具有内部上拉电阻。在flash编程时，P0程序校验时，需要外部上拉电阻。P1口是一个具有内部上拉电阻的8位双向I/O输出缓冲器能驱动4个TTLP1端口写“1”（IIP1.0和P1.2分别作定时器计数器2（P1.0/T2）和时器/计数器2的触发输入（P1.1/T2EX），flash口接收低8位地址字节。P2口是一个具有内部上拉电阻的8位双向I/O输出缓冲器能驱动4个TTLP2端口写“1”16位地址读取外部数据存储器（例如执行MOVX@DPTR）口使用很强