外文文獻(xiàn)及翻譯-單片機(jī)

1、<p><b>　　單片機(jī)</b></p><p><b>　　1 單片機(jī)定義 </b></p><p>　　單片機(jī)是指一個(gè)集成在一塊芯片上的完整計(jì)算機(jī)系統(tǒng)。盡管它的大部分功能集成在一塊小芯片上，但是它具有一個(gè)完整計(jì)算機(jī)所需要的大部分部件：CPU、內(nèi)存、內(nèi)部和外部總線(xiàn)系統(tǒng)，目前大部分還會(huì)具有外存。同時(shí)集成諸如通訊接口、定時(shí)器，實(shí)時(shí)時(shí)鐘

2、等外圍設(shè)備。而現(xiàn)在最強(qiáng)大的單片機(jī)系統(tǒng)甚至可以將聲音、圖像、網(wǎng)絡(luò)、復(fù)雜的輸入輸出系統(tǒng)集成在一塊芯片上。</p><p>　　單片機(jī)也被稱(chēng)為微控制器（Microcontroller Unit），常用英文字母的縮寫(xiě)MCU表示單片機(jī)，它最早是被用在工業(yè)控制領(lǐng)域。單片機(jī)由芯片內(nèi)僅有CPU的專(zhuān)用處理器發(fā)展而來(lái)。最早的設(shè)計(jì)理念是通過(guò)將大量外圍設(shè)備和CPU集成在一個(gè)芯片中，使計(jì)算機(jī)系統(tǒng)更小，更容易集成進(jìn)復(fù)雜的而對(duì)體積要求嚴(yán)格的控

3、制設(shè)備當(dāng)中。INTEL的Z80是最早按照這種思想設(shè)計(jì)出的處理器，從此以后，單片機(jī)和專(zhuān)用處理器的發(fā)展便分道揚(yáng)鑣。 </p><p>　　早期的單片機(jī)都是8位或4位的。其中最成功的是INTEL的8031，因?yàn)楹?jiǎn)單可靠而性能不錯(cuò)獲得了很大的好評(píng)。此后在8031上發(fā)展出了MCS51系列單片機(jī)系統(tǒng)?；谶@一系統(tǒng)的單片機(jī)系統(tǒng)直到現(xiàn)在還在廣泛使用。隨著工業(yè)控制領(lǐng)域要求的提高，開(kāi)始出現(xiàn)了16位單片機(jī)，但因?yàn)樾詢(xún)r(jià)比不理想并未得到很

4、廣泛的應(yīng)用。90年代后隨著消費(fèi)電子產(chǎn)品大發(fā)展，單片機(jī)技術(shù)得到了巨大提高。隨著INTEL i960系列特別是后來(lái)的ARM系列的廣泛應(yīng)用，32位單片機(jī)迅速取代16位單片機(jī)的高端地位，并且進(jìn)入主流市場(chǎng)。而傳統(tǒng)的8位單片機(jī)的性能也得到了飛速提高，處理能力比起80年代提高了數(shù)百倍。目前，高端的32位單片機(jī)主頻已經(jīng)超過(guò)300MHz，性能直追90年代中期的專(zhuān)用處理器，而普通的型號(hào)出廠(chǎng)價(jià)格跌落至1美元，最高端的型號(hào)也只有10美元。當(dāng)代單片機(jī)系統(tǒng)已經(jīng)不再

5、只在裸機(jī)環(huán)境下開(kāi)發(fā)和使用，大量專(zhuān)用的嵌入式操作系統(tǒng)被廣泛應(yīng)用在全系列的單片機(jī)上。而在作為掌上電腦和手機(jī)核心處理的高端單片機(jī)甚至可以直接使用專(zhuān)用的Windows和Linux操作系統(tǒng)。 </p><p>　　單片機(jī)比專(zhuān)用處理器更適合應(yīng)用于嵌入式系統(tǒng)，因此它得到了最多的應(yīng)用。事實(shí)上單片機(jī)是世界上數(shù)量最多的計(jì)算機(jī)?，F(xiàn)代人類(lèi)生活中所用的幾乎每件電子和機(jī)械產(chǎn)品中都會(huì)集成有單片機(jī)。手機(jī)、電話(huà)、計(jì)算器、家用電器、電子玩具、掌上電

6、腦以及鼠標(biāo)等電腦配件中都配有1-2部單片機(jī)。而個(gè)人電腦中也會(huì)有為數(shù)不少的單片機(jī)在工作。汽車(chē)上一般配備40多部單片機(jī)，復(fù)雜的工業(yè)控制系統(tǒng)上甚至可能有數(shù)百臺(tái)單片機(jī)在同時(shí)工作！單片機(jī)的數(shù)量不僅遠(yuǎn)超過(guò)PC機(jī)和其他計(jì)算的總和，甚至比人類(lèi)的數(shù)量還要多。 </p><p><b>　　2 單片機(jī)介紹</b></p><p>　　單片機(jī)又稱(chēng)單片微控制器,它不是完成某一個(gè)邏輯功能的芯片

7、,而是把一個(gè)計(jì)算機(jī)系統(tǒng)集成到一個(gè)芯片上。相當(dāng)于一個(gè)微型的計(jì)算機(jī)，和計(jì)算機(jī)相比，單片機(jī)只缺少了I/O設(shè)備。概括的講：一塊芯片就成了一臺(tái)計(jì)算機(jī)。它的體積小、質(zhì)量輕、價(jià)格便宜、為學(xué)習(xí)、應(yīng)用和開(kāi)發(fā)提供了便利條件。同時(shí)，學(xué)習(xí)使用單片機(jī)是了解計(jì)算機(jī)原理與結(jié)構(gòu)的最佳選擇。 </p><p>　　單片機(jī)內(nèi)部也用和電腦功能類(lèi)似的模塊，比如CPU，內(nèi)存，并行總線(xiàn)，還有和硬盤(pán)作用相同的存儲(chǔ)器件，不同的是它的這些部件性能都相對(duì)我們的家用

8、電腦弱很多，不過(guò)價(jià)錢(qián)也是低的，一般不超過(guò)10元即可......用它來(lái)做一些控制電器一類(lèi)不是很復(fù)雜的工作足矣了。我們現(xiàn)在用的全自動(dòng)滾筒洗衣機(jī)、排煙罩、VCD等等的家電里面都可以看到它的身影！......它主要是作為控制部分的核心部件。 </p><p>　　它是一種在線(xiàn)式實(shí)時(shí)控制計(jì)算機(jī)，在線(xiàn)式就是現(xiàn)場(chǎng)控制，需要的是有較強(qiáng)的抗干擾能力，較低的成本，這也是和離線(xiàn)式計(jì)算機(jī)的（比如家用PC）的主要區(qū)別。 </p>

9、;<p>　　單片機(jī)是靠程序運(yùn)行的，并且可以修改。通過(guò)不同的程序?qū)崿F(xiàn)不同的功能，尤其是特殊的獨(dú)特的一些功能，這是別的器件需要費(fèi)很大力氣才能做到的，有些則是花大力氣也很難做到的。一個(gè)不是很復(fù)雜的功能要是用美國(guó)50年代開(kāi)發(fā)的74系列，或者60年代的CD4000系列這些純硬件來(lái)搞定的話(huà)，電路一定是一塊大PCB板！但是如果要是用美國(guó)70年代成功投放市場(chǎng)的系列單片機(jī)，結(jié)果就會(huì)有天壤之別！只因?yàn)閱纹瑱C(jī)的通過(guò)你編寫(xiě)的程序可以實(shí)現(xiàn)高智能，

10、高效率，以及高可靠性！ </p><p>　　由于單片機(jī)對(duì)成本是敏感的，所以目前占統(tǒng)治地位的軟件還是最低級(jí)匯編語(yǔ)言，它是除了二進(jìn)制機(jī)器碼以上最低級(jí)的語(yǔ)言了，既然這么低級(jí)為什么還要用呢？很多高級(jí)的語(yǔ)言已經(jīng)達(dá)到了可視化編程的水平為什么不用呢？原因很簡(jiǎn)單，就是單片機(jī)沒(méi)有家用計(jì)算機(jī)那樣的CPU，也沒(méi)有像硬盤(pán)那樣的海量存儲(chǔ)設(shè)備。一個(gè)可視化高級(jí)語(yǔ)言編寫(xiě)的小程序里面即使只有一個(gè)按鈕，也會(huì)達(dá)到幾十K的尺寸！對(duì)于家用PC的硬盤(pán)來(lái)講

11、沒(méi)什么，可是對(duì)于單片機(jī)來(lái)講是不能接受的。 單片機(jī)在硬件資源方面的利用率必須很高才行，所以匯編雖然原始卻還是在大量使用。一樣的道理，如果把巨型計(jì)算機(jī)上的操作系統(tǒng)和應(yīng)用軟件拿到家用PC上來(lái)運(yùn)行，家用PC的也是承受不了的。 </p><p>　　可以說(shuō)，二十世紀(jì)跨越了三個(gè)“電”的時(shí)代，即電氣時(shí)代、電子時(shí)代和現(xiàn)已進(jìn)入的電腦時(shí)代。不過(guò)，這種電腦，通常是指?jìng)€(gè)人計(jì)算機(jī)，簡(jiǎn)稱(chēng)PC機(jī)。它由主機(jī)、鍵盤(pán)、顯示器等組成。還有一類(lèi)計(jì)算機(jī)，

12、大多數(shù)人卻不怎么熟悉。這種計(jì)算機(jī)就是把智能賦予各種機(jī)械的單片機(jī)（亦稱(chēng)微控制器）。顧名思義，這種計(jì)算機(jī)的最小系統(tǒng)只用了一片集成電路，即可進(jìn)行簡(jiǎn)單運(yùn)算和控制。因?yàn)樗w積小，通常都藏在被控機(jī)械的“肚子”里。它在整個(gè)裝置中，起著有如人類(lèi)頭腦的作用，它出了毛病，整個(gè)裝置就癱瘓了?，F(xiàn)在，這種單片機(jī)的使用領(lǐng)域已十分廣泛，如智能儀表、實(shí)時(shí)工控、通訊設(shè)備、導(dǎo)航系統(tǒng)、家用電器等。各種產(chǎn)品一旦用上了單片機(jī)，就能起到使產(chǎn)品升級(jí)換代的功效，常在產(chǎn)品名稱(chēng)前冠以形容

13、詞——“智能型”，如智能型洗衣機(jī)等。現(xiàn)在有些工廠(chǎng)的技術(shù)人員或其它業(yè)余電子開(kāi)發(fā)者搞出來(lái)的某些產(chǎn)品，不是電路太復(fù)雜，就是功能太簡(jiǎn)單且極易被仿制。究其原因，可能就卡在產(chǎn)品未使用單片機(jī)或其它可編程邏輯器件上。 </p><p><b>　　3 單片機(jī)歷史</b></p><p>　　單片機(jī)誕生于20世紀(jì)70年代末，經(jīng)歷了SCM、MCU、SOC三大階段。</p>

14、<p>　　（1）SCM即單片微型計(jì)算機(jī)（Single Chip Microcomputer）階段，主要是尋求最佳的單片形態(tài)嵌入式系統(tǒng)的最佳體系結(jié)構(gòu)。“創(chuàng)新模式”獲得成功，奠定了SCM與通用計(jì)算機(jī)完全不同的發(fā)展道路。在開(kāi)創(chuàng)嵌入式系統(tǒng)獨(dú)立發(fā)展道路上，Intel公司功不可沒(méi)。 </p><p>　?。?）MCU即微控制器（Micro Controller Unit）階段，主要的技術(shù)發(fā)展方向是：不斷擴(kuò)展?jié)M足嵌

15、入式應(yīng)用時(shí)，對(duì)象系統(tǒng)要求的各種外圍電路與接口電路，突顯其對(duì)象的智能化控制能力。它所涉及的領(lǐng)域都與對(duì)象系統(tǒng)相關(guān)，因此，發(fā)展MCU的重任不可避免地落在電氣、電子技術(shù)廠(chǎng)家。從這一角度來(lái)看，Intel逐漸淡出MCU的發(fā)展也有其客觀(guān)因素。在發(fā)展MCU方面，最著名的廠(chǎng)家當(dāng)數(shù)Philips公司。 </p><p>　　Philips公司以其在嵌入式應(yīng)用方面的巨大優(yōu)勢(shì)，將MCS-51從單片微型計(jì)算機(jī)迅速發(fā)展到微控制器。因此，當(dāng)我

16、們回顧嵌入式系統(tǒng)發(fā)展道路時(shí)，不要忘記Intel和Philips的歷史功績(jī)。 </p><p>　?。?）嵌入式系統(tǒng)階段，單片機(jī)是嵌入式系統(tǒng)的獨(dú)立發(fā)展之路，向MCU階段發(fā)展的重要因素，就是尋求應(yīng)用系統(tǒng)在芯片上的最大化解決；因此，專(zhuān)用單片機(jī)的發(fā)展自然形成了SOC化趨勢(shì)。隨著微電子技術(shù)、IC設(shè)計(jì)、EDA工具的發(fā)展，基于SOC的單片機(jī)應(yīng)用系統(tǒng)設(shè)計(jì)會(huì)有較大的發(fā)展。因此，對(duì)單片機(jī)的理解可以從單片微型計(jì)算機(jī)、單片微控制器延伸到

17、單片應(yīng)用系統(tǒng)。 </p><p>　　4 單片機(jī)的應(yīng)用領(lǐng)域</p><p>　　目前單片機(jī)滲透到我們生活的各個(gè)領(lǐng)域，幾乎很難找到哪個(gè)領(lǐng)域沒(méi)有單片機(jī)的蹤跡。導(dǎo)彈的導(dǎo)航裝置，飛機(jī)上各種儀表的控制，計(jì)算機(jī)的網(wǎng)絡(luò)通訊與數(shù)據(jù)傳輸，工業(yè)自動(dòng)化過(guò)程的實(shí)時(shí)控制和數(shù)據(jù)處理，廣泛使用的各種智能IC卡，民用豪華轎車(chē)的安全保障系統(tǒng)，錄像機(jī)、攝像機(jī)、全自動(dòng)洗衣機(jī)的控制，以及程控玩具、電子寵物等等，這些都離不開(kāi)單片機(jī)

18、。更不用說(shuō)自動(dòng)控制領(lǐng)域的機(jī)器人、智能儀表、醫(yī)療器械了。因此，單片機(jī)的學(xué)習(xí)、開(kāi)發(fā)與應(yīng)用將造就一批計(jì)算機(jī)應(yīng)用與智能化控制的科學(xué)家、工程師。 </p><p>　　單片機(jī)廣泛應(yīng)用于儀器儀表、家用電器、醫(yī)用設(shè)備、航空航天、專(zhuān)用設(shè)備的智能化管理及過(guò)程控制等領(lǐng)域，大致可分如下幾個(gè)范疇： </p><p>　　（1）在智能儀器儀表上的應(yīng)用 </p><p>　　單片機(jī)具有體積小、

19、功耗低、控制功能強(qiáng)、擴(kuò)展靈活、微型化和使用方便等優(yōu)點(diǎn)，廣泛應(yīng)用于儀器儀表中，結(jié)合不同類(lèi)型的傳感器，可實(shí)現(xiàn)諸如電壓、功率、頻率、濕度、溫度、流量、速度、厚度、角度、長(zhǎng)度、硬度、元素、壓力等物理量的測(cè)量。采用單片機(jī)控制使得儀器儀表數(shù)字化、智能化、微型化，且功能比起采用電子或數(shù)字電路更加強(qiáng)大。例如精密的測(cè)量設(shè)備（功率計(jì)，示波器，各種分析儀）。 </p><p>　?。?）在工業(yè)控制中的應(yīng)用 </p>&l

20、t;p>　　用單片機(jī)可以構(gòu)成形式多樣的控制系統(tǒng)、數(shù)據(jù)采集系統(tǒng)。例如工廠(chǎng)流水線(xiàn)的智能化管、電梯智能化控制、各種報(bào)警系統(tǒng)，與計(jì)算機(jī)聯(lián)網(wǎng)構(gòu)成二級(jí)控制系統(tǒng)等。 </p><p>　?。?）在家用電器中的應(yīng)用 </p><p>　　可以這樣說(shuō)，現(xiàn)在的家用電器基本上都采用了單片機(jī)控制，從電飯褒、洗衣機(jī)、電冰箱、空調(diào)機(jī)、彩電、其他音響視頻器材、再到電子秤量設(shè)備，五花八門(mén)，無(wú)所不在。 </p

21、><p>　　（4）在計(jì)算機(jī)網(wǎng)絡(luò)和通信領(lǐng)域中的應(yīng)用 </p><p>　　現(xiàn)代的單片機(jī)普遍具備通信接口，可以很方便地與計(jì)算機(jī)進(jìn)行數(shù)據(jù)通信，為在計(jì)算機(jī)網(wǎng)絡(luò)和通信設(shè)備間的應(yīng)用提供了極好的物質(zhì)條件，現(xiàn)在的通信設(shè)備基本上都實(shí)現(xiàn)了單片機(jī)智能控制，從手機(jī)，電話(huà)機(jī)、小型程控交換機(jī)、樓宇自動(dòng)通信呼叫系統(tǒng)、列車(chē)無(wú)線(xiàn)通信、再到日常工作中隨處可見(jiàn)的移動(dòng)電話(huà)，集群移動(dòng)通信，無(wú)線(xiàn)電對(duì)講機(jī)等。 </p>&

22、lt;p>　　（5）單片機(jī)在醫(yī)用設(shè)備領(lǐng)域中的應(yīng)用 </p><p>　　單片機(jī)在醫(yī)用設(shè)備中的用途亦相當(dāng)廣泛，例如醫(yī)用呼吸機(jī)，各種分析儀，監(jiān)護(hù)儀，超聲診斷設(shè)備及病床呼叫系統(tǒng)等等。 </p><p>　　（6）在各種大型電器中的模塊化應(yīng)用 </p><p>　　某些專(zhuān)用單片機(jī)設(shè)計(jì)用于實(shí)現(xiàn)特定功能，從而在各種電路中進(jìn)行模塊化應(yīng)用，而不要求使用人員了解其內(nèi)部結(jié)構(gòu)。如音

23、樂(lè)集成單片機(jī)，看似簡(jiǎn)單的功能，微縮在純電子芯片中（有別于磁帶機(jī)的原理），就需要復(fù)雜的類(lèi)似于計(jì)算機(jī)的原理。如：音樂(lè)信號(hào)以數(shù)字的形式存于存儲(chǔ)器中（類(lèi)似于ROM），由微控制器讀出，轉(zhuǎn)化為模擬音樂(lè)電信號(hào)（類(lèi)似于聲卡）。 </p><p>　　在大型電路中，這種模塊化應(yīng)用極大地縮小了體積，簡(jiǎn)化了電路，降低了損壞、錯(cuò)誤率，也方便于更換。 </p><p>　?。?）單片機(jī)在汽車(chē)設(shè)備領(lǐng)域中的應(yīng)用 <

24、;/p><p>　　單片機(jī)在汽車(chē)電子中的應(yīng)用非常廣泛，例如汽車(chē)中的發(fā)動(dòng)機(jī)控制器，基于CAN總線(xiàn)的汽車(chē)發(fā)動(dòng)機(jī)智能電子控制器，GPS導(dǎo)航系統(tǒng)，abs防抱死系統(tǒng)，制動(dòng)系統(tǒng)等等。 </p><p>　　此外，單片機(jī)在工商，金融，科研、教育，國(guó)防航空航天等領(lǐng)域都有著十分廣泛的用途。 </p><p>　　5 AT89C52單片機(jī)介紹</p><p>　　A

25、T89C52是美國(guó)Atmel公司生產(chǎn)的低電壓、高性能CMOS 8位單片機(jī)，片內(nèi)含8KB的可反復(fù)擦寫(xiě)的程序存儲(chǔ)器和12B的隨機(jī)存取數(shù)據(jù)存儲(chǔ)器（RAM），器件采用Atmel公司的高密度、非易失性存儲(chǔ)技術(shù)生產(chǎn)，兼容標(biāo)準(zhǔn)MCS-51指令系統(tǒng)，片內(nèi)配置通用8位中央處理器（CPU）和Flash存儲(chǔ)單元，功能強(qiáng)大的AT89C52單片機(jī)可靈活應(yīng)用于各種控制領(lǐng)域。AT89C52單片機(jī)屬于A(yíng)T89C51單片機(jī)的增強(qiáng)型，與Intel公司的80C52在引腳排列

26、、硬件組成、工作特點(diǎn)和指令系統(tǒng)等方面兼容。</p><p><b>　　其主要工作特性是：</b></p><p>　　片內(nèi)程序存儲(chǔ)器內(nèi)含8KB的Flash程序存儲(chǔ)器，可擦寫(xiě)壽命為1000次；</p><p>　　片內(nèi)數(shù)據(jù)存儲(chǔ)器內(nèi)含256字節(jié)內(nèi)部RAM；</p><p>　　具有32根可編程I/O口線(xiàn)；</p>

27、;<p>　　具有3個(gè)可編程定時(shí)器；</p><p>　　2個(gè)可編程I/O口線(xiàn)；</p><p>　　中斷系統(tǒng)具有8個(gè)中斷源；</p><p>　　串行口是具有一個(gè)全雙工的可編程串行通信口；</p><p>　　低功耗工作模式有空閑模式和掉電模式；</p><p>　　具有可編程的3級(jí)程序鎖定位；<

28、/p><p>　　AT89C52最高工作頻率為24MHz。</p><p><b>　　功能特性描述：</b></p><p>　　AT89C52是一種低功耗、高性能CMOS8位微控制器，具有8K在系統(tǒng)可編程Flash存儲(chǔ)器，使用Atmel公司的高密度、非易失性存儲(chǔ)技術(shù)制造，與工業(yè)80C51產(chǎn)品指令和引腳完全兼容。片上Flash允許程序存儲(chǔ)器在系統(tǒng)

29、可編程，亦適用于常規(guī)編程器。在單芯片上，擁有靈巧的8位CPU和在系統(tǒng)可編程Flash，使得AT89C52為眾多嵌入式控制應(yīng)用系統(tǒng)提供高靈活、超有效的解決方案。</p><p>　　AT89C52具有以下標(biāo)準(zhǔn)功能：</p><p>　　8k字節(jié)Flash，256字節(jié)RAM，32位I/O口線(xiàn)，看門(mén)狗定時(shí)器，2個(gè)數(shù)據(jù)指針，三個(gè)16位定時(shí)/計(jì)數(shù)器，一個(gè)6向量2級(jí)中斷結(jié)構(gòu)，全雙工串行口，片內(nèi)晶振及時(shí)

30、鐘電路。另外，AT89C52可降至0Hz靜態(tài)邏輯操作，支持2種軟件可選擇節(jié)電模式?？臻e模式下，CPU停止工作，允許RAM、定時(shí)/計(jì)數(shù)器、串口、中斷繼續(xù)工作。掉電保護(hù)方式下，RAM內(nèi)容被保存，振蕩器被凍結(jié)，單片機(jī)一切工作停止，知道下一個(gè)中斷或硬件復(fù)位為止。8位微控制器、8K字節(jié)在系統(tǒng)可編程。</p><p>　　AT89C52有40個(gè)引腳，32個(gè)外部雙向輸入/輸出（I/O）端口，同時(shí)內(nèi)含2個(gè)外中端口，3個(gè)16位可編

31、程定時(shí)計(jì)數(shù)器，2個(gè)全雙工串行通信口，2個(gè)讀寫(xiě)口線(xiàn)，AT89C52可以按照常規(guī)方法進(jìn)行編程，也可以在線(xiàn)編程。其將通用的微處理器和Flash存儲(chǔ)器結(jié)合在一起，特別是可反復(fù)擦寫(xiě)的Flash存儲(chǔ)器可有效的降低開(kāi)發(fā)成本。</p><p><b>　　MCU</b></p><p>　　1 The definition of MCU</p><p>　　M

32、CU is an integrated on a single chip a complete computer system.Even though most of his features in a small chip,but it has a need to complete the majority of computer components:CPU,memory,internal and external bus syst

33、em,most will have the Core.At the same time,such as integrated communication interfaces,times,real-time</p><p>　　Clock and other peripheral equipment.And now the most powerful MCU microcomputer system can ev

34、en voice,image,networking,input and output complex system integration on a single chip.</p><p>　　Also known as single-chip MCU(Microcontroller),because it was first used in the field of industrial control.On

35、ly by the single-chip CPU chip developed from the dedicated processor.The design concept is the first by a large number of peripherals and CPU in a single chip,the computer system so that smaller,more easily integrated i

36、nto the complex and demanding on the volume control devices.INTEL the Z80 is one of the first design in accordance with the idea of the processor,From then on,the MCU and</p><p>　　Early MCU 8-bit or all of t

37、he four. One of the most successful is the INTEL 8031, because the performance of a simple and reliable access to a lot of good praise. Then developed in 8031 out of MCS51 MCU Systems. SCM systems based on this system un

38、til now is still widely used. With the increased requirements of industrial control field, began a 16-bit microcontroller, because the cost is not satisfactory but have not been very widely used. After 90 years with the

39、great development of consumer ele</p><p>　　More than a dedicated MCU processor suitable for embedded systems, so it was up to the application. In fact the number of SCM is the world's largest computer. M

40、odern human life used in almost every piece of electronic and mechanical products will be integrated single chip.Phone, telephone, calculator, home appliances, electronic toys, handheld computers and computer accessories

41、 such as a mouse with a 1-2 in both the Department of SCM. Personal computer will have a large number of SCM in the work</p><p>　　2 MCU introduced</p><p>　　MCU ,also known as single-chip microco

42、ntroller, it is not complete a certain logic chips, but to a computer system integrated into a chip.Equivalent to a micro-computer, and computer than just the lack of a microcontroller I / O devices. General talk: a chip

43、 becomes a computer. Its small size, light weight, cheap, for the study, application and development of facilities provided. At the same time, learning to use the MCU is to understand the principle and structure of the c

44、omputer the best choic</p><p>　　MCU and the computer use is also similar to the module, such as CPU, memory, parallel bus, as well as the role and the same hard disk memory,is it different from the performan

45、ce of these components are relatively weak in our home computer a lot ,but the price is low , there is generally no more than 10 yuan ......can use it to make some control for a class of electrical work is not very compl

46、ex is sufficient.We are using automatic drum washing machines ,smoke hood, VCD and so on inside the home </p><p>　　It is an online real-time control computer, control-line is that the scene is needed is a st

47、ronger anti-jamming ability, low cost, and this is, and off-line computer (such as home PC), the main difference.</p><p>　　By single-chip process ,and can be amended.Through different procedures to achieve d

48、ifferent functions, in particular special unique features, this is another device much effort needs to be done, some great efforts are very difficult to do. A not very complex functions if the 50's with the United St

49、ates developed 74 series, or the 60's CD4000 series of these pure hardware buttoned, then the circuit must be a large PCB board! But if the United States if the 70's with a series of successful SCM ma</p>

50、<p>　　As the microcontroller on the cost-sensitive, so now the dominant software or the lowest level assembly language, which is the lowest level in addition to more than binary machine code language, and as so low

51、why is the use? Many high-level language has reached the level of visual programming Why is not it? The reason is simply that there is no home computer as a single chip CPU, not as hard as a mass storage device.A visuali

52、zation of small high-level language program which even if only one butt</p><p>　　Can be said that the twentieth century across the three "power" era, that is, the age of electricity, the electronic

53、 age and has entered into the computer age. However, this computer, usually refers to the personal computer, referred to as PC. It consists of the host, keyboard, monitor and other components. Another type of computer, m

54、ost people do not know how. This computer is to give all kinds of intelligent machines single chip (also known as micro-controller). As the name suggests, this comp</p><p>　　3 MCU history</p><p>

55、;　　Single-chip 70 was born in the late 20th century, experienced a SCM, MCU, SOC three stages.（1）SCM the single chip microcomputer (Single Chip Microcomputer) stage, mainly seeking the best of the best single form of em

56、bedded systems architecture. "Innovation model" success, laying the SCM and general computer completely different path of development. In the open road of independent development of embedded systems, Intel Corp

57、oration contributed.</p><p>　?。?）MCU the micro-controller (Micro Controller Unit) stage, the main direction of technology development: expanding to meet the embedded applications, the target system requireme

58、nts for the various peripheral circuits and interface circuits, highlight the object of intelligent control.It involves the areas associated with the object system, therefore, the development of MCU's responsibility

59、inevitably falls on electrical, electronics manufacturers. From this point of view, Intel faded MCU develop</p><p>　　Philips company in embedded applications, its great advantage, the MCS-51 single-chip micr

60、o-computer from the rapid development of the micro-controller. Therefore, when we look back at the path of development of embedded systems, do not forget Intel and Philips in History. （3）Embedded system microcontroller i

61、s an independent development path, the MCU important factor in the development stage, is seeking applications to maximize the solution on the chip; Therefore, the development of dedicated si</p><p>　　4 MCU a

62、pplications At present,MCU to infiltrate all areas of our lives, which is almost difficult to find traces of the field without SCM. Missile navigation equipment, aircraft, all types of instrument control, computer net

63、work communications and data transmission, industrial automation, real-time process control and data processing, extensive use of various smart IC card, civilian luxury car security system, video recorder, camera, fully

64、automatic washing machine control, and program-contro</p><p>　　（1）In the application of Intelligent Instruments SCM has a small size, low power consumption, controlling function, expansion flexibility, t

65、he advantages of miniaturization and ease of use, widely used instrument, combining different types of sensors can be realized Zhuru voltage, power, frequency, humidity, temperature, flow, speed, thickness, angle, length

66、, hardness, elemental, physical pressure measurement. SCM makes use of digital instruments, intelligence, miniaturization, and functiona</p><p>　?。?）In the industrial control application With the MCU ca

67、n constitute a variety of control systems, data acquisition system. Such as factory assembly line of intelligent control,all kinds of alarm systems,and computer networks constitute a secondary control system.</p>

68、<p>　?。?）In the Appliance of Household appliances It can be said that the appliances are basically using SCM, praise from the electric rice, washing machines, refrigerators, air conditioners, color TV, and oth

69、er audio video equipment, to the electronic weighing equipment, varied, and omnipresent.（4）In the field of computer networks and communications applications MCU general with modern communication interface, can be e

70、asy with the computer data communication, networking and communications</p><p>　?。?）Microcomputer in the field of medical device applications MCU in the use of medical devices is also quite extensive, su

71、ch as medical respirator, the various analyzers, monitors, ultrasound diagnostic equipment and hospital beds, etc. call system. （6）In a variety of major appliances in the modular applications Designed to achieve so

72、me special single specific function to be modular in a variety of circuit applications, without requiring the use of personnel to understand its internal </p><p>　　5.AT89C52 chip explains</p><p>

73、;　　The AT89C52 is a low-power,high-performance CMOS 8-bit microcomputer with 8 K bytes of Flash programmable and erasable read only memory(PEROM).The device is manufactured using Atmel's high density nonvolatile memo

74、ry technology and is compatible with the industry standard 80C51 and 80C52 instruction set and pinot.The on-chip Flash allows the program memory to be reprogrammed in-system or by a conbventional onwolatile memory progra

75、mmer.By combining a versatile 8-bit CPU with Flash on a monolithic </p><p><b>　　Eatures:</b></p><p>　　8 K bytes of In-system Reprogrammable Flash Memory;Endurance:1000 Write/Erase Cy

76、cles</p><p>　　256×8 bit Internal RAM</p><p>　　32 Programmable I/O Lines</p><p>　　Three 16-Bit Timer/Counters</p><p>　　Eight Interrupt Sources</p><p>　

77、　Programmable Serial Channel</p><p>　　Low Power Idle and Power Down Modes</p><p>　　Three-Level Program Memory Lock </p><p>　　Fully Static Operation:0 Hz to 24 MHz</p><p&g

78、t;　　Description</p><p>　　The AT89C52 is a low-power,high-performance COMS 8-bit microcomputer</p><p>　　with 8K bytes of Flash programmable and erasable read only memory(PEROM).The device is manu

79、factured using Atmel's high density nonvolatile memory technology and is compatible with the industry standard 80C51 and 80C52 instruction set and pinot.The on-chip Flash allows the program memory to be reprogrammed

80、in-system or by a conventional onvolatile memory programmer.By combining a versatile 8-bit CPU with Flash on a monolithic chip,the Atmel AT89C52 is a powerful microcomputer,which provides a hig</p><p>　　The

81、AT89C52 provides the following standard features:</p><p>　　8k bytes of Flash ,256 bytes of RAM,32 I/O lines,three 16-bit timer/counters,a six-vector two-level interrupt architecture , a full duplex serial po

82、rt,on-chip oscillator,and clock circuitry . In addition, the AT89C52 is designed with static logic of operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU

83、while allowing the RAM,timer/counter,serial port,and interrupt system to continue functioning. The Power Down Mode saves the RAM con</p><p>　　AT89C52 40 pins, 32 external bi-directional input/output(I/O)port

84、s, and includes two external interrupt ports, three 16-bit programmable timer counters, two full duplex serial port, 2 a read-write port line,AT89C52 can be programmed according to conventional method, also available onl