欢迎来到人人文库网! | 帮助中心 人人文库renrendoc.com美如初恋!
人人文库网
首页 人人文库网 > 资源分类 > DOC文档下载

外文翻译--AT89S51概述.doc

  • 资源大小:51.00KB        全文页数:9页
  • 资源格式: DOC        下载权限:游客/注册会员/VIP会员    下载费用:5
游客快捷下载 游客一键下载
会员登录下载
下载资源需要5

邮箱/手机号:
您支付成功后,系统会自动为您创建此邮箱/手机号的账号,密码跟您输入的邮箱/手机号一致,以方便您下次登录下载和查看订单。注:支付完成后需要自己下载文件,并不会自动发送文件哦!

支付方式: 微信支付    支付宝   
验证码:   换一换

友情提示
2、本站资源不支持迅雷下载,请使用浏览器直接下载(不支持QQ浏览器)
3、本站资源下载后的文档和图纸-无水印,预览文档经过压缩,下载后原文更清晰   

外文翻译--AT89S51概述.doc

THEDESCRIPTIONOFAT89S511GENERALDESCRIPTIONTHEAT89S51ISALOWPOWER,HIGHPERFORMANCECMOS8BITMICROCONTROLLERWITH4KBYTESOFINSYSTEMPROGRAMMABLEFLASHMEMORYTHEDEVICEISMANUFACTUREDUSINGATMEL’SHIGHDENSITYNONVOLATILEMEMORYTECHNOLOGYANDISCOMPATIBLEWITHTHEINDUSTRYSTANDARD80C51INSTRUCTIONSETANDPINOUTTHEONCHIPFLASHALLOWSTHEPROGRAMMEMORYTOBEREPROGRAMMEDINSYSTEMORBYACONVENTIONALNONVOLATILEMEMORYPROGRAMMERBYCOMBININGAVERSATILE8BITCPUWITHINSYSTEMPROGRAMMABLEFLASHONAMONOLITHICCHIP,THEATMELAT89S51ISAPOWERFULMICROCONTROLLERWHICHPROVIDESAHIGHLYFLEXIBLEANDCOSTEFFECTIVESOLUTIONTOMANYEMBEDDEDCONTROLAPPLICATIONSTHEAT89S51PROVIDESTHEFOLLOWINGSTANDARDFEATURES4KBYTESOFFLASH,128BYTESOFRAM,32I/OLINES,WATCHDOGTIMER,TWODATAPOINTERS,TWO16BITTIMER/COUNTERS,AFIVEVECTORTWOLEVELINTERRUPTARCHITECTURE,AFULLDUPLEXSERIALPORT,ONCHIPOSCILLATOR,ANDCLOCKCIRCUITRYINADDITION,THEAT89S51ISDESIGNEDWITHSTATICLOGICFOROPERATIONDOWNTOZEROFREQUENCYANDSUPPORTSTWOSOFTWARESELECTABLEPOWERSAVINGMODESTHEIDLEMODESTOPSTHECPUWHILEALLOWINGTHERAM,TIMER/COUNTERS,SERIALPORT,ANDINTERRUPTSYSTEMTOCONTINUEFUNCTIONINGTHEPOWERDOWNMODESAVESTHERAMCONTENTSBUTFREEZESTHEOSCILLATOR,DISABLINGALLOTHERCHIPFUNCTIONSUNTILTHENEXTEXTERNALINTERRUPTORHARDWARERESET2PORTSPORT0ISAN8BITOPENDRAINBIDIRECTIONALI/OPORTASANOUTPUTPORT,EACHPINCANSINKEIGHTTTLINPUTSWHEN1SAREWRITTENTOPORT0PINS,THEPINSCANBEUSEDASHIGHIMPEDANCEINPUTSPORT0CANALSOBECONFIGUREDTOBETHEMULTIPLEXEDLOWORDERADDRESS/DATABUSDURINGACCESSESTOEXTERNALPROGRAMANDDATAMEMORYINTHISMODE,P0HASINTERNALPULLUPSPORT0ALSORECEIVESTHECODEBYTESDURINGFLASHPROGRAMMINGANDOUTPUTSTHECODEBYTESDURINGPROGRAMVERIFICATIONEXTERNALPULLUPSAREREQUIREDDURINGPROGRAMVERIFICATIONPORT1ISAN8BITBIDIRECTIONALI/OPORTWITHINTERNALPULLUPSTHEPORT1OUTPUTBUFFERSCANSINK/SOURCEFOURTTLINPUTSWHEN1SAREWRITTENTOPORT1PINS,THEYAREPULLEDHIGHBYTHEINTERNALPULLUPSANDCANBEUSEDASINPUTSASINPUTS,PORT1PINSTHATAREEXTERNALLYBEINGPULLEDLOWWILLSOURCECURRENTIILBECAUSEOFTHEINTERNALPULLUPSPORT1ALSORECEIVESTHELOWORDERADDRESSBYTESDURINGFLASHPROGRAMMINGANDVERIFICATIONPORT2ISAN8BITBIDIRECTIONALI/OPORTWITHINTERNALPULLUPSTHEPORT2OUTPUTBUFFERSCANSINK/SOURCEFOURTTLINPUTSWHEN1SAREWRITTENTOPORT2PINS,THEYAREPULLEDHIGHBYTHEINTERNALPULLUPSANDCANBEUSEDASINPUTSASINPUTS,PORT2PINSTHATAREEXTERNALLYBEINGPULLEDLOWWILLSOURCECURRENTIILBECAUSEOFTHEINTERNALPULLUPSPORT2EMITSTHEHIGHORDERADDRESSBYTEDURINGFETCHESFROMEXTERNALPROGRAMMEMORYANDDURINGACCESSESTOEXTERNALDATAMEMORYTHATUSE16BITADDRESSESMOVXDPTRINTHISAPPLICATION,PORT2USESSTRONGINTERNALPULLUPSWHENEMITTING1SDURINGACCESSESTOEXTERNALDATAMEMORYTHATUSE8BITADDRESSESMOVXRI,PORT2EMITSTHECONTENTSOFTHEP2SPECIALFUNCTIONREGISTERPORT2ALSORECEIVESTHEHIGHORDERADDRESSBITSANDSOMECONTROLSIGNALSDURINGFLASHPROGRAMMINGANDVERIFICATIONPORT3ISAN8BITBIDIRECTIONALI/OPORTWITHINTERNALPULLUPSTHEPORT3OUTPUTBUFFERSCANSINK/SOURCEFOURTTLINPUTSWHEN1SAREWRITTENTOPORT3PINS,THEYAREPULLEDHIGHBYTHEINTERNALPULLUPSANDCANBEUSEDASINPUTSASINPUTS,PORT3PINSTHATAREEXTERNALLYBEINGPULLEDLOWWILLSOURCECURRENTIILBECAUSEOFTHEPULLUPSPORT3RECEIVESSOMECONTROLSIGNALSFORFLASHPROGRAMMINGANDVERIFICATIONPORT3ALSOSERVESTHEFUNCTIONSOFVARIOUSSPECIALFEATURESOFTHEAT89S51,ASSHOWNINTHEFOLLOWINGTABLE3SPECIALFUNCTIONREGISTERSAMAPOFTHEONCHIPMEMORYAREACALLEDTHESPECIALFUNCTIONREGISTERSFRSPACEISSHOWNINTABLE51NOTETHATNOTALLOFTHEADDRESSESAREOCCUPIED,ANDUNOCCUPIEDADDRESSESMAYNOTBEIMPLEMENTEDONTHECHIPREADACCESSESTOTHESEADDRESSESWILLINGENERALRETURNRANDOMDATA,ANDWRITEACCESSESWILLHAVEANINDETERMINATEEFFECTUSERSOFTWARESHOULDNOTWRITE1STOTHESEUNLISTEDLOCATIONS,SINCETHEYMAYBEUSEDINFUTUREPRODUCTSTOINVOKENEWFEATURESINTHATCASE,THERESETORINACTIVEVALUESOFTHENEWBITSWILLALWAYSBE0INTERRUPTREGISTERSTHEINDIVIDUALINTERRUPTENABLEBITSAREINTHEIEREGISTERTWOPRIORITIESCANBESETFOREACHOFTHEFIVEINTERRUPTSOURCESINTHEIPREGISTERDUALDATAPOINTERREGISTERSTOFACILITATEACCESSINGBOTHINTERNALANDEXTERNALDATAMEMORY,TWOBANKSOF16BITDATAPOINTERREGISTERSAREPROVIDEDDP0ATSFRADDRESSLOCATIONS82H83HANDDP1AT84H85HBITDPS0INSFRAUXR1SELECTSDP0ANDDPS1SELECTSDP1THEUSERSHOULDALWAYSINITIALIZETHEDPSBITTOTHEAPPROPRIATEVALUEBEFOREACCESSINGTHERESPECTIVEDATAPOINTERREGISTERPOWEROFFFLAGTHEPOWEROFFFLAGPOFISLOCATEDATBIT4PCON4INTHEPCONSFRPOFISSETTO“1”DURINGPOWERUPITCANBESETANDRESTUNDERSOFTWARECONTROLANDISNOTAFFECTEDBYRESET4MEMORYORGANIZATIONMCS51DEVICESHAVEASEPARATEADDRESSSPACEFORPROGRAMANDDATAMEMORYUPTO64KBYTESEACHOFEXTERNALPROGRAMANDDATAMEMORYCANBEADDRESSED41PROGRAMMEMORYIFTHEEAPINISCONNECTEDTOGND,ALLPROGRAMFETCHESAREDIRECTEDTOEXTERNALMEMORYONTHEAT89S51,IFEAISCONNECTEDTOVCC,PROGRAMFETCHESTOADDRESSES0000HTHROUGHFFFHAREDIRECTEDTOINTERNALMEMORYANDFETCHESTOADDRESSES1000HTHROUGHFFFFHAREDIRECTEDTOEXTERNALMEMORY42DATAMEMORYTHEAT89S51IMPLEMENTS128BYTESOFONCHIPRAMTHE128BYTESAREACCESSIBLEVIADIRECTANDINDIRECTADDRESSINGMODESSTACKOPERATIONSAREEXAMPLESOFINDIRECTADDRESSING,SOTHE128BYTESOFDATARAMAREAVAILABLEASSTACKSPACE7WATCHDOGTIMERONETIMEENABLEDWITHRESETOUTTHEWDTISINTENDEDASARECOVERYMETHODINSITUATIONSWHERETHECPUMAYBESUBJECTEDTOSOFTWAREUPSETSTHEWDTCONSISTSOFA14BITCOUNTERANDTHEWATCHDOGTIMERRESETWDTRSTSFRTHEWDTISDEFAULTEDTODISABLEFROMEXITINGRESETTOENABLETHEWDT,AUSERMUSTWRITE01EHAND0E1HINSEQUENCETOTHEWDTRSTREGISTERSFRLOCATION0A6HWHENTHEWDTISENABLED,ITWILLINCREMENTEVERYMACHINECYCLEWHILETHEOSCILLATORISRUNNINGTHEWDTTIMEOUTPERIODISDEPENDENTONTHEEXTERNALCLOCKFREQUENCYTHEREISNOWAYTODISABLETHEWDTEXCEPTTHROUGHRESETEITHERHARDWARERESETORWDTOVERFLOWRESETWHENWDTOVERFLOWS,ITWILLDRIVEANOUTPUTRESETHIGHPULSEATTHERSTPIN5USINGTHEWDTTOENABLETHEWDT,AUSERMUSTWRITE01EHAND0E1HINSEQUENCETOTHEWDTRSTREGISTERSFRLOCATION0A6HWHENTHEWDTISENABLED,THEUSERNEEDSTOSERVICEITBYWRITING01EHAND0E1HTOWDTRSTTOAVOIDAWDTOVERFLOWTHE14BITCOUNTEROVERFLOWSWHENITREACHES163833FFFH,ANDTHISWILLRESETTHEDEVICEWHENTHEWDTISENABLED,ITWILLINCREMENTEVERYMACHINECYCLEWHILETHEOSCILLATORISRUNNINGTHISMEANSTHEUSERMUSTRESETTHEWDTATLEASTEVERY16383MACHINECYCLESTORESETTHEWDTTHEUSERMUSTWRITE01EHAND0E1HTOWDTRSTWDTRSTISAWRITEONLYREGISTERTHEWDTCOUNTERCANNOTBEREADORWRITTENWHENWDTOVERFLOWS,ITWILLGENERATEANOUTPUTRESETPULSEATTHERSTPINTHERESETPULSEDURATIONIS98XTOSC,WHERETOSC1/FOSCTOMAKETHEBESTUSEOFTHEWDT,ITSHOULDBESERVICEDINTHOSESECTIONSOFCODETHATWILLPERIODICALLYBEEXECUTEDWITHINTHETIMEREQUIREDTOPREVENTAWDTRESETINPOWERDOWNMODETHEOSCILLATORSTOPS,WHICHMEANSTHEWDTALSOSTOPSWHILEINPOWERDOWNMODE,THEUSERDOESNOTNEEDTOSERVICETHEWDTTHEREARETWOMETHODSOFEXITINGPOWERDOWNMODEBYAHARDWARERESETORVIAALEVELACTIVATEDEXTERNALINTERRUPT,WHICHISENABLEDPRIORTOENTERINGPOWERDOWNMODEWHENPOWERDOWNISEXITEDWITHHARDWARERESET,SERVICINGTHEWDTSHOULDOCCURASITNORMALLYDOESWHENEVERTHEAT89S51ISRESETEXITINGPOWERDOWNWITHANINTERRUPTISSIGNIFICANTLYDIFFERENTTHEINTERRUPTISHELDLOWLONGENOUGHFORTHEOSCILLATORTOSTABILIZEWHENTHEINTERRUPTISBROUGHTHIGH,THEINTERRUPTISSERVICEDTOPREVENTTHEWDTFROMRESETTINGTHEDEVICEWHILETHEINTERRUPTPINISHELDLOW,THEWDTISNOTSTARTEDUNTILTHEINTERRUPTISPULLEDHIGHITISSUGGESTEDTHATTHEWDTBERESETDURINGTHEINTERRUPTSERVICEFORTHEINTERRUPTUSEDTOEXITPOWERDOWNMODETOENSURETHATTHEWDTDOESNOTOVERFLOWWITHINAFEWSTATESOFEXITINGPOWERDOWN,ITISBESTTORESETTHEWDTJUSTBEFOREENTERINGPOWERDOWNMODEBEFOREGOINGINTOTHEIDLEMODE,THEWDIDLEBITINSFRAUXRISUSEDTODETERMINEWHETHERTHEWDTCONTINUESTOCOUNTIFENABLEDTHEWDTKEEPSCOUNTINGDURINGIDLEWDIDLEBIT0ASTHEDEFAULTSTATETOPREVENTTHEWDTFROMRESETTINGTHEAT89S51WHILEINIDLEMODE,THEUSERSHOULDALWAYSSETUPATIMERTHATWILLPERIODICALLYEXITIDLE,SERVICETHEWDT,ANDREENTERIDLEMODEWITHWDIDLEBITENABLED,THEWDTWILLSTOPTOCOUNTINIDLEMODEANDRESUMESTHECOUNTUPONEXITFROMIDLETIMER0ANDTIMER1INTHEAT89S51OPERATETHESAMEWAYASTIMER0ANDTIMER1INTHEAT89C51FORFURTHERINFORMATIONONTHETIMERS’OPERATION,PLEASECLICKONTHEDOCUMENTLINKBELOWHTTP//WWWATMELCOM/DYN/RESOURCES/PROD_DOCUMENTS/DOC4316PDF6INTERRUPTSTHEAT89S51HASATOTALOFFIVEINTERRUPTVECTORSTWOEXTERNALINTERRUPTSINT0ANDINT1,TWOTIMERINTERRUPTSTIMERS0AND1,ANDTHESERIALPORTINTERRUPTTHESEINTERRUPTSAREALLSHOWNINFIGURE101EACHOFTHESEINTERRUPTSOURCESCANBEINDIVIDUALLYENABLEDORDISABLEDBYSETTINGORCLEARINGABITINSPECIALFUNCTIONREGISTERIEIEALSOCONTAINSAGLOBALDISABLEBIT,EA,WHICHDISABLESALLINTERRUPTSATONCENOTETHATTABLE101SHOWSTHATBITPOSITIONSIE6ANDIE5AREUNIMPLEMENTEDUSERSOFTWARESHOULDNOTWRITE1STOTHESEBITPOSITIONS,SINCETHEYMAYBEUSEDINFUTUREAT89PRODUCTSTHETIMER0ANDTIMER1FLAGS,TF0ANDTF1,ARESETATS5P2OFTHECYCLEINWHICHTHETIMERSOVERFLOWTHEVALUESARETHENPOLLEDBYTHECIRCUITRYINTHENEXTCYCLE7OSCILLATORCHARACTERISTICSXTAL1ANDXTAL2ARETHEINPUTANDOUTPUT,RESPECTIVELY,OFANINVERTINGAMPLIFIERTHATCANBECONFIGUREDFORUSEASANONCHIPOSCILLATOR,ASSHOWNINFIGURE111EITHERAQUARTZCRYSTALORCERAMICRESONATORMAYBEUSEDTODRIVETHEDEVICEFROMANEXTERNALCLOCKSOURCE,XTAL2SHOULDBELEFTUNCONNECTEDWHILEXTAL1ISDRIVEN,ASSHOWNINFIGURE112THEREARENOREQUIREMENTSONTHEDUTYCYCLEOFTHEEXTERNALCLOCKSIGNAL,SINCETHEINPUTTOTHEINTERNALCLOCKINGCIRCUITRYISTHROUGHADIVIDEBYTWOFLIPFLOP,BUTMINIMUMANDMAXIMUMVOLTAGEHIGHANDLOWTIMESPECIFICATIONSMUSTBEOBSERVED

注意事项

本文(外文翻译--AT89S51概述.doc)为本站会员(英文资料库)主动上传,人人文库网仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对上载内容本身不做任何修改或编辑。 若此文所含内容侵犯了您的版权或隐私,请立即通知人人文库网(发送邮件至[email protected]或直接QQ联系客服),我们立即给予删除!

温馨提示:如果因为网速或其他原因下载失败请重新下载,重复下载不扣分。

关于我们 - 网站声明 - 网站地图 - 资源地图 - 友情链接 - 网站客服客服 - 联系我们

网站客服QQ:2846424093    人人文库上传用户QQ群:460291265   

[email protected] 2016-2018  renrendoc.com 网站版权所有   南天在线技术支持

经营许可证编号:苏ICP备12009002号-5