AT89S52Word文件下载.docx

AT89S52Word文件下载.docx

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•4.0Vto5.5VOperatingRange

•FullyStaticOperation:

0Hzto33MHz

•Three-levelProgramMemoryLock

•256x8-bitInternalRAM

•32ProgrammableI/OLines

•Three16-bitTimer/Counters

•EightInterruptSources

•FullDuplexUARTSerialChannel

•Low-powerIdleandPower-downModes

•InterruptRecoveryfromPower-downMode

•WatchdogTimer•DualDataPointer

•Power-offFlag•FastProgrammingTime

•FlexibleISPProgramming（ByteandPageMode）

•Green（Pb/Halide-free）PackagingOption

1.Description

TheAT89S52isalow-power,high-performanceCMOS8-bitmicrocontrollerwith8Kbytesofin-systemprogrammableFlashmemory.ThedeviceismanufacturedusingAtmel’shigh-densitynonvolatilememorytechnologyandiscompatiblewiththeindus-try-standard80C51instructionsetandpinout.Theon-chipFlashallowstheprogrammemorytobereprogrammedin-systemorbyaconventionalnonvolatilememorypro-grammer.Bycombiningaversatile8-bitCPUwithin-systemprogrammableFlashonamonolithicchip,theAtmelAT89S52isapowerfulmicrocontrollerwhichprovidesahighly-flexibleandcost-effectivesolutiontomanyembeddedcontrolapplications.

TheAT89S52providesthefollowingstandardfeatures:

8KbytesofFlash,256bytesofRAM,32I/Olines,Watchdogtimer,twodatapointers,three16-bittimer/counters,asix-vectortwo-levelinterruptarchitecture,afullduplexserialport,on-chiposcillator,andclockcircuitry.Inaddition,theAT89S52isdesignedwithstaticlogicforoperationdowntozerofrequencyandsupportstwosoftwareselectablepowersavingmodes.TheIdleModestopstheCPUwhileallowingtheRAM,timer/counters,serialport,andinterruptsystemtocontinuefunctioning.ThePower-downmodesavestheRAMcon-tentsbutfreezestheoscillator,disablingallotherchipfunctionsuntilthenextinterruptorhardwarereset.

2.PinDescription

VCC：

Supplyvoltage.

GND：

Ground.

Port0：

Port0isan8-bitopendrainbidirectionalI/Oport.Asanoutputport,eachpincansinkeightTTLinputs.When1sarewrittentoport0pins,thepinscanbeusedashigh-impedanceinputs.Port0canalsobeconfiguredtobethemultiplexedlow-orderaddress/databusduringaccessestoexternalprogramanddatamemory.Inthismode,P0hasinternalpull-ups.Port0alsoreceivesthecodebytesduringFlashprogrammingandoutputsthecodebytesdur-ingprogramverification.Externalpull-upsarerequiredduringprogramverification.

Port1：

Port1isan8-bitbidirectionalI/Oportwithinternalpull-ups.ThePort1outputbufferscansink/sourcefourTTLinputs.When1sarewrittentoPort1pins,theyarepulledhighbytheinter-nalpull-upsandcanbeusedasinputs.Asinputs,Port1pinsthatareexternallybeingpulledlowwillsourcecurrent（IIL）becauseoftheinternalpull-ups.Inaddition,P1.0andP1.1canbeconfiguredtobethetimer/counter2externalcountinput（P1.0/T2）andthetimer/counter2triggerinput（P1.1/T2EX）,respectively,asshowninthefollow-ingtable.

Port1alsoreceivesthelow-orderaddressbytesduringFlashprogrammingandverification.

Table1

PortPin

AlternateFunctions

P1.0

T2（externalcountinputtoTimer/Counter2）,clock-out

P1.1

T2EX（Timer/Counter2capture/reloadtriggeranddirectioncontrol）

P1.5

MOSI（usedforIn-SystemProgramming）

P1.6

MISO（usedforIn-SystemProgramming）

P1.7

SCK（usedforIn-SystemProgramming）

Port2：

Port2isan8-bitbidirectionalI/Oportwithinternalpull-ups.ThePort2outputbufferscansink/sourcefourTTLinputs.When1sarewrittentoPort2pins,theyarepulledhighbytheinter-nalpull-upsandcanbeusedasinputs.Asinputs,Port2pinsthatareexternallybeingpulledlowwillsourcecurrent（IIL）becauseoftheinternalpull-ups.Port2emitsthehigh-orderaddressbyteduringfetchesfromexternalprogrammemoryanddur-ingaccessestoexternaldatamemorythatuse16-bitaddresses（MOVX@DPTR）.Inthisapplication,Port2usesstronginternalpull-upswhenemitting1s.Duringaccessestoexternaldatamemorythatuse8-bitaddresses（MOVX@RI）,Port2emitsthecontentsoftheP2SpecialFunctionRegister.Port2alsoreceivesthehigh-orderaddressbitsandsomecontrolsignalsduringFlashprogram-mingandverification.

Port3：

Port3isan8-bitbidirectionalI/Oportwithinternalpull-ups.ThePort3outputbufferscansink/sourcefourTTLinputs.When1sarewrittentoPort3pins,theyarepulledhighbytheinter-nalpull-upsandcanbeusedasinputs.Asinputs,Port3pinsthatareexternallybeingpulledlowwillsourcecurrent（IIL）becauseofthepull-ups.Port3receivessomecontrolsignalsforFlashprogrammingandverification.Port3alsoservesthefunctionsofvariousspecialfeatu