1、ChipSTC12C5204ADI/OportconfigurationSTC12C5204ADseriesmicrocontrolleritsallI/Oportsarecontrolledbythesoftwareconfigurationinto4kindsofworktype4typesarerespectively:quasitwo-waymouth(standardthe8051outputmode),push-pulloutput,onlyforinput(highresistance)oropen-drainoutputfunctions.Everymouthconsistso

2、ftwocontrolregistertherelevantpositioncontroleachpintypeofwork.STC12C5204ADseriesmicrocontrollertoelectricityreattachmentshallprevailtwo-waymouth(standardthe8051outputmode)mode:2Vabovehighlevel,0.8Vforlowlevelbelow.1. Quasitwo-waymouthoutputconfigurationQuasitwo-waymouthoutputtypecanbeusedasoutputan

3、dinputfunctionbutdon'tneedtoreconfiguremouthlinesoutputstate.Thisisbecausejuncturelinesoutputis1driveabilityisveryweak,allowingexternaldeviceswillitsdown.Whenpinsforlow,itoutputdrivingability,canabsorbtheconsiderablecurrent.Quasitwo-waymouthhave3pull_uptransistoradaptedtodifferentneeds.Inthethre

4、eandonetransistor,pulluptransistorcalledweakonpull",for1andpaternallineregistersitselfpinsfor1open.Thispull_upprovidesbasicdrivecurrentmakeprospectivetwo-waymouthfor1output.Ifapinfor1andoutputbyexternaldevicestodropdowntolow,pullupcloseandweak"veryweakpull_up"maintainopenposition,inor

5、dertoputthispinforlow,strongtopulltheexternaldevicesmusthaveenoughpowertomakepininfusedcurrentthresholdvoltageofavoltagetothefollowing.Article2pull_uptransistors,called"extremelyweakonpull",1latchpaternallinewhenopen.Whenpin,theveryweaksuspendedthepull_upsourcegeneratesveryweakandcurrentwi

6、llpinandhighlevel.Article3pull_uptransistorcalled"powerfulpull".Juncturelinelatchesfrom0to1,thejumpingtoacceleratemustpullupbylogic0totwo-waymouthlogic1conversion.Whenthishappened,powerfulpullopenabout2machinecycletomakepinscanquicklypulltotheearthhighlevel.Quasitwo-waymouthoutputshownbelo

7、w.STC12C520seriesmicrocontroller3Vdevice,iftheuserisinpinsplus5Vvoltage,therewillbeacurrentflowfrompins,thishascausedadditionalVDDpowerconsumption.Accordingly,theproposalisnotinquasitwo-waymouthmode3Vmicrocontrollerpinstoexert5Vvoltage,suchastheuseofwords,willaddcurrentlimitingresistor,orusingdioded

8、oinputisolation,orusetriodedooutputsegregation.Quasitwo-waymouthwithaschmidttriggerinputandainterfereneesuppressioncircuit.2. Thepush-pulloutputconfigurationThedrop-downpush-pulloutputconfigurationopen-drainoutputandthestructureandtheprospectivetwo-waymouthdownsamestructure,butwhenlatchesis1provides

9、continuousstrongpullup.Thepush-pullmodelneedmorecommonlyusedfordrivingcurrentsituation.Thepush-pullpinsconfigurationareshownbelow.LI詵存:竝捕<x理am3. Onlyforinput(highresistanee)configurationInputportconfigurationareshownbelow.靖14潦尙嶽也可承受綸山低時僅比輸人m時.不奪佻駆入20“巾漩的能乍収！':或VIJv：.：'洛口丁制Inputportwithasc

10、hmidttriggerinputandainterferencesuppressioncircuit.4. Open-drainoutputconfigurationJuncturelinelatchesis0,theopen-drainoutputcloseallpull_uptransistors.When,asalogicaloutput,thisconfigurationmodemusthaveexternallypull,usuallybyresistancereceivingVDDoutside.Thisstyleofdrop-downandquasitwo-waymouthth

11、esame.Thejammerlineconfigurationareshownbelow.Open-drainportwithaschmidttriggerinputandainterferencesuppressioncircuit.輸出恆時AtypicaltransistorcontrolcircuitIfuseweakpull_upcontrol,suggestonpluspull-upresistorsR1(3.3K10K),ifnotaddpull-upresistorsR1(3.3K10K),suggestR2valueinthe15Kabove,oruseastrongpush

12、-pulloutput.STC12C5204ADseriesmicrocontrollerprogrammablecounterarray(PCA)PCAcontainsaspecial16timer,hasfour16bitsofcapture/comparisonofmoduleandconnected.EachmoduleprogrammableworkInfourmode:increase/decreasealongthecapture,softwaretimer,high-speedoutputorcouldbemodulatedpulseoutput.Modulesconnecte

13、dtoP3.7(0CEX0/PCA0/PWM0),module1connectedtoP3.5(CEX1/PCA1/PWM1),modulesconnectedtoP2.0(2CEX2/PCA2/PWM2),modulesconnectedtoP2.4(3CEX3/PCA3/PWM3).RegisterthecontentofCHandCLisfreeof16PCAincreasingcountthevalueofthetimer.PCAtimerisfourmodules,thepublictimebenchmarkbyprogrammingwork.ProgrammableCounterA

14、rrayTOPCAadulchast.12FCAli£t<rxuptIDLFcr»L-”1-1CPalECFLCFCF-LCCF2CCFlCCFO|CCONPCATimer/CounterCMODSFRthereare2bytesandPCArelated.Theywere:CIDL,idlemodeallowsstopPCA;ECF,buya,enablingPCAinterrupt,whenPCAtimerspilloverwillPCAcountingoverflowmarksCCONSFR(CF)buybits.CCONSFRcontainsPCAoperat

15、ingcontrolbits(CR)andPCAtimermark(CF)andsymbolofeachmoduleCCF3/CCF2(CCFO).CCF1/ThroughthesoftwareforaCRbits(CCON.6)torunPCA.CRbitisresetwhenPCAclosed.WhenPCAcounteroverflow,CFpatients(CCON.7)buya,ifCMODregister,itproducesECFpositionadisruption.CFbitscanonlythroughsoftwarecleared.CCONregistera03isPCA

16、moduleslogo(a00,acorrespondingmodule1correspondingmodule1,bits2correspondingmodule2,a3correspondingmodule3),whenthereisamatchorbyhardwarebuyacomparisons.Thesesignalsaretheonlythroughsoftwarecleared.-ESn丨估F門|“刑眾TnT檢丨Wn丨X®.爲咒;上：寫aoooPCAcaptureofpatterningIfCCONSFRbitsofthethroneofCCFnandCCAPMnSFR

17、ECCFnbitissetposition,willproducetheinterruption.AsoftwaretimermodeThroughtheCCAPMnregistersforaECOMandMATbits,canmakethePCAmoduleusedforsoftwaretimer(below).PCAtimervaluesandmoduleoftheregistercomparedtocapture,whenbothvaluesequal,ifaCCONSFRinCCFn(in)andaECCFnCCAPMnSFR)inallbuybits,willproducethein

18、terruption.A'IduIoCL'AP-I7/riletoCCAfnHF*£'r-?itC"m?itati>rlaCCFnCF|CR一CCF3WE|CCF1CCFDViTthTTT|-Erou-<?A?Fn|C4PXn00MATTOGnFnFCCTr.rrurPCASoftwareTimerMode/SoftwareTimermodel/PCAcomparativeModePCASoftwareTimerMode/SoftwareTimermodel/PCAcomparativeModeHigh-speedoutputmodelT

19、hismodel(below),whenPCAcounterplanofthenumericalandmodulecaptureregistersmatching,PCAvalueCEXnoutputwillhappenmoduleoftheflip.Toactivatethehigh-speedoutputmodesofCCAPMnTOGSFR,modules,MATandECOMbitmustbuybits.PCAHigh-Speed,OutputMode/PCAhigh-speedOutputMode先寫后駕Xrltc5CCAPrtLitCCAPnK<r-ccC(T2cmccn1f

20、1(IWiOAftiLIT1血-=ircflup.iriTorfttrCHCLEaabt?：7:：CTr.CE?x-ECOMn|CAPPnCAE'nMATnF¥Nn|EOTdtoo1(JCCAPUnInusePCAhigh-speedoutputmodespecialapplicationnote:IfacertainPCAmoduleworkinginhighspeedpulseoutputmode,wanttousesoftwareoutputchangethesamegroupofothercommonI/Oportstate,needtodofirst,whether

21、CCAPnHjudgeCHisequaltoabide,canfreelymodify,ifequal,anddetermineCCAPnLcircumstances>CLisallowedtochangethesamegroupofothercommonI/Oportstate.IfuseP3.7/PCA0/PWMOdoPCAhigh-speedpulseoutput,andtheprograminsideandwithsoftwareoutputchangewhenthestateP3.4mouth,youneedtodojudgment.WhenonehasthePCAhigh-s

22、peedpulseoutputfunctionofI/Omouthworkinginhighspeedpulseoutputmode,ifthesoftwareforthesamegroupofotherI/Oportoperation,ifmeetPCAcomparatormatching,thisoperationcanchangethepulseoutputfunctionwithPCAhigh-speedmouthoftheI/O.E?CnECCAPnHJ：!"Pul-0.>=:EF*CnL:匸CAPtiL“輸出LCOFlin,n=0,1-£<X

23、7;tnL-irti.CAFXriIItATnECCFn1000110CLIo9-BTTCOMPARATOR0CLPCAPWMmode/modulationpulsewidthoutputmodeSinceallshareonlyPCAtimermodules,alltheiroutputfrequencyissame.Theoutputofeachmodule390visindependentofthechanges,andusingEPCnL,capturedCCAPnLofregistersconcerned.WhenCLSFRvalueislessthanCCAPnLEPCnL,whe

24、noutputislow,andthevalueofSFRwhenPCACLisequaltoorgreaterthanEPCnL,CCAPnL,theoutputashigh.WhenthevalueoftheCLbyFFintoEPCnH,00overflow,CCAPnHthecontentsofEPCnL,loadedintotheCCAPnL.Inthisway,canrealizeupdatePWMwithoutinterference.TomakeCCAPMnpWmmode,modulecanPWMnandECOMnbitsoftheregistertobuybits.譯文芯片S

25、TC12C5204AD的I/O口配置STC12C5204AD系列單片機其所有I/O口均可由軟件配置成4種工作類型4種類型分別為：準雙向口（標準8051輸出模式）、推挽輸出、僅為輸入（高阻）或開漏輸出功能。每個口由2個控制寄存器中的相應(yīng)位控制每個引腳工作類型。STC12C5204AD系列單片機上電復位后為準雙向口（標準8051輸出模式）模式：2V以上時為高電平，0.8V以下時為低電平。1.準雙向口輸出配置準雙向口輸出類型可用作輸出和輸入功能而不需重新配置口線輸出狀態(tài)。這是因為當口線輸出為1時驅(qū)動能力很弱，允許外部裝置將其拉低。當引腳輸出為低時，它的驅(qū)動能力很強，可吸收相當大的電流。準雙向口有3個

26、上拉晶體管適應(yīng)不同的需要。在3個上拉晶體管中，有1個上拉晶體管稱為“弱上拉”，當口線寄存器為1且引腳本身也為1時打開。此上拉提供基本驅(qū)動電流使準雙向口輸出為1。如果一個引腳輸出為1而由外部裝置下拉到低時，弱上拉關(guān)閉而“極弱上拉”維持開狀態(tài)，為了把這個引腳強拉為低，外部裝置必須有足夠的灌電流能力使引腳上的電壓降到門檻電壓以下。第2個上拉晶體管，稱為“極弱上拉”，當口線鎖存為1時打開。當引腳懸空時，這個極弱的上拉源產(chǎn)生很弱的上拉電流將引腳上拉為高電平。第3個上拉晶體管稱為“強上拉”。當口線鎖存器由0到1跳變時，這個上拉用來加快準雙向口由邏輯0到邏輯1轉(zhuǎn)換。當發(fā)生這種情況時，強上拉打開約2個機器周期

27、以使引腳能夠迅速地上拉到高電平。準雙向口輸出如下圖所示。STC12C520系列單片機為3V器件，如果用戶在引腳加上5V電壓，將會有電流從引腳流向VDD，這樣導致額外的功率消耗。因此，建議不要在準雙向口模式中向3V單片機引腳施加5V電壓,如使用的話，要加限流電阻，或用二極管做輸入隔離，或用三極管做輸出隔離。準雙向口帶有一個施密特觸發(fā)輸入以及一個干擾抑制電路2.推挽輸出配置推挽輸出配置的下拉結(jié)構(gòu)與開漏輸出以及準雙向口的下拉結(jié)構(gòu)相同，但當鎖存器為1時提供持續(xù)的強上拉。推挽模式一般用于需要更大驅(qū)動電流的情況。推挽引腳配置如下圖所示。.il/i'：）濛尙嶽也可承受綸山低時3.僅為輸入（高阻）配置

28、輸入口配置如下圖所示。輸入口帶有一個施密特觸發(fā)輸入以及一個干擾抑制電路。4開漏輸出配置當口線鎖存器為0時，開漏輸出關(guān)閉所有上拉晶體管。當作為一個邏輯輸出時,這種配置方式必須有外部上拉，一般通過電阻外接到VDD。這種方式的下拉與準雙向口相同。輸出口線配置如下圖所示。開漏端口帶有一個施密特觸發(fā)輸入以及一個干擾抑制電路一種典型三極管控制電路如果用弱上拉控制，建議加上拉電阻R1(3.3K10K)，如果不加上拉電阻R1(3.3K10K)，建議R2的值在15K以上，或用強推挽輸出。STC12C5204AD系列單片機可編程計數(shù)器陣列(PCA)PCA含有一個特殊的16位定時器，有4個16位的捕獲/比較模塊與之

29、相連。每個模塊可編程工作。在4種模式下：上升/下降沿捕獲、軟件定時器、高速輸出或可調(diào)制脈沖輸出。模塊0連接到P3.7(CEXO/PCAO/PWMO)，模塊1連接到P3.5(CEX1/PCA1/PWM1)，模塊2連接到P2.0(CEX2/PCA2/PWM2)，模塊3連接到P2.4(CEX3/PCA3/PWM3)。寄存器CH和CL的內(nèi)容是正在自由遞增計數(shù)的16位PCA定時器的值。PCA定時器是4個模塊的公共時間基準，可通過編程工作在：1/12振蕩頻率、1/2振蕩頻率、定時器0溢出或ECI腳的輸入(P3.4)。定時器的計數(shù)源由CMODSFR的CPS1和CPSO位來確定（見CMOD特殊功能寄存器說明）

30、o可編程計數(shù)器陣列PCA定時器/計數(shù)器CMODSFR還有2個位與PCA相關(guān)。它們分別是：CIDL，空閑模式下允許停止PCA；ECF，置位時，使能PCA中斷，當PCA定時器溢出將PCA計數(shù)溢出標志CF（CCONSFR）置位。CCONSFR包含PCA的運行控制位（CR）和PCA定時器標志（CF）以及各個模塊的標志（CCF3/CCF2/CCF1/CCF0）。通過軟件置位CR位（CCON.6）來運行PCA。CR位被清零時PCA關(guān)閉。當PCA計數(shù)器溢出時，CF位(CC0N.7)置位,如果CMOD寄存器的ECF位置位,就產(chǎn)生中斷。CF位只可通過軟件清除。CCON寄存器的位03是PCA各個模塊的標志(位0對

31、應(yīng)模塊0,位1對應(yīng)模塊1,位2對應(yīng)模塊2,位3對應(yīng)模塊3)，當發(fā)生匹配或比較時由硬件置位。這些標志也只能通過軟件清除。所有模塊共用一個中斷向量。PCA的中斷系統(tǒng)如圖所示。PCA的每個模塊都對應(yīng)一個特殊功能寄存器。它們分別是：模塊0對應(yīng)CCAPM0,模塊1對應(yīng)CCAPM1,模塊2對應(yīng)CCAPM2，模塊3對應(yīng)CCAPM3。特殊功能寄存器包含了相應(yīng)模塊的工作模式控制位。當模塊發(fā)生匹配或比較時，ECCFn位(CCAPMn.0,n=0,1,2,3由工作的模塊決定)使能CCONSFR的CCFn標志來產(chǎn)生中斷。PWM(CCAPMn.1)用來使能脈寬調(diào)制模式。當PCA計數(shù)值與模塊的捕獲/比較寄存器的值相匹配時

32、,如果TOG位(CCAPMn.2)置位，模塊的CEXn輸出將發(fā)生翻轉(zhuǎn)。當PCA計數(shù)值與模塊的捕獲/比較寄存器的值相匹配時,如果匹配位MATn(CCAPMn.3)置位，CCON寄存器的CCFn位將被置位。CAPNn(CCAPMn.4)和CAPPn(CCAPMn.5)用來設(shè)置捕獲輸入的有效沿。CAPNn位使能下降沿有效,CAPPn位使能上升沿有效。如果兩位都置位,則兩種跳變沿都被使能,捕獲可在兩種跳變沿產(chǎn)生。通過置位CCAPMn寄存器的ECOMn位(CCAPMn.6)來使能比較器功能。每個PCA模塊還對應(yīng)另外兩個寄存器，CCAPnH和CCAPnL。當出現(xiàn)捕獲或比較時，它們用來保存16位的計數(shù)值。當PCA模塊用在PWM模式中時，它們用來控制輸出的占空比。PCA捕獲模式要使一個PCA模塊工作在捕獲模式(下圖),寄存器CCAPMn的兩位(CAPNn和CAPPn)或其中任何一位必須置1。對模塊的外部CEXn輸入(CEX0/P3.7,CEX1/P3.5,CEX2/P2.0,CEX3/P2.4口)的跳變進行采樣。當采樣到有效跳變時，PCA硬件就將PCA計數(shù)器陣列寄存器(CH和CL)的值裝