單片機(jī)外文翻譯兩篇

1、<p><b>　　目錄</b></p><p><b>　　第一章 單片機(jī)</b></p><p>　　外文文獻(xiàn)原文………………………………………………1</p><p>　　中文文獻(xiàn)譯文………………………………………………8</p><p>　　第二章 DS18B20資料</p

2、><p>　　外文文獻(xiàn)原文……………………………………………14</p><p>　　中文文獻(xiàn)譯文……………………………………………17</p><p><b>　　單片機(jī)</b></p><p><b>　　外文文獻(xiàn)原文：</b></p><p>　　MCU Descripti

3、onSCM is also known as micro-controller (Microcontroller Unit), commonly used letters of the acronym MCU MCU that it was first used in industrial control. Only a single chip by the CPU chip developed from a dedicated pro

4、cessor. The first design is by a large number of peripherals and CPU on a chip in the computer system, smaller, more easily integrated into a complex and demanding on the volume control device which. INTEL's Z80 is t

5、he first designed in accordance with this idea proc</p><p>　　Are 8-bit microcontroller early or 4 bits. One of the most successful is the INTEL 8031, for a simple, reliable and good performance was a lot of

6、praise. Then developed in 8031 out of MCS51 MCU Systems. SCM systems based on this system until now is still widely used. With the increased requirements of industrial control field, began a 16-bit microcontroller, becau

7、se the cost is not satisfactory but have not been very widely used. After 90 years with the great development of consumer electronics,</p><p>　　SCM is more suitable than the specific processor used in embedd

8、ed systems, so it was up to the application. In fact the number of SCM is the world's largest computer. Modern human life used in almost every piece of electronic and mechanical products will be integrated single chi

9、p. Phone, telephone, calculator, home appliances, electronic toys, handheld computers and computer accessories such as a mouse with a 1-2 in both the Department of SCM. Personal computer will have a large number of SCM i

10、n</p><p>　　Single chip, also known as single-chip microcontroller, 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

11、 just the lack of a microcontroller I / O devices. General talk: a chip becomes a computer. Its small size, light weight, cheap, for the study, application and development of facilities provided. At the same time, learni

12、ng to use the MCU is to understand the principle and structure of the computer the b</p><p>　　SCM and the computer functions internally with similar modules, such as CPU, memory, parallel bus, the same effec

13、t as well, and hard disk memory devices, and different is its performance of these components were relatively weak many of our home computer, but the price is low , usually not more than 10 yuan you can do with it ......

14、 some control for a class is not very complicated electrical work is enough of. We are using automatic drum washing machine, smoke hood, VCD and so on appliances which</p><p>　　It is an online real-time cont

15、rol computer, control-line is that the scene is needed is a stronger anti-jamming ability, low cost, and this is, and off-line computer (such as home PC), the main difference.</p><p>　　Single chipMCU is thro

16、ugh running, and can be modified. Through different procedures to achieve different functions, in particular special unique features, this is another device much effort needs to be done, some great efforts are very diffi

17、cult to do. A not very complex functions if the 50's with the United States 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 U

18、nited States if the 70's with a series of succ</p><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 addi

19、tion to more than binary machine code language, and as so low 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 s

20、ingle chip CPU, not as hard as a mass storage device. A visualization of small high-level language program which even if only one but</p><p>　　Can be said that the twentieth century across the three "po

21、wer" era, that is, the age of electricity, the electronic 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, keybo

22、ard, monitor and other components. Another type of computer, most 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, thi

23、s comp</p><p>　　SCM historySCM was born in the late 20th century, 70, experienced SCM, MCU, SoC three stages.First model1.SCM the single chip microcomputer (Single Chip Microcomputer) stage, mainly seeking t

24、he best of the best single form of embedded systems architecture. "Innovation model" success, laying the SCM and general computer completely different path of development. In the open road of independent develo

25、pment of embedded systems, Intel Corporation contributed.</p><p>　　2.MCU the micro-controller (Micro Controller Unit) stage, the main direction of technology development: expanding to meet the embedded appli

26、cations, the target system requirements 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 dev

27、elopment of MCU's responsibility inevitably falls on electrical, electronics manufacturers. From this point of view, Intel faded MCU develop</p><p>　　MCU applications SCM now permeate all areas of our li

28、ves, which is almost difficult to find traces of the field without SCM. Missile navigation equipment, aircraft, all types of instrument control, computer network communications and data transmission, industrial automatio

29、n, real-time process control and data processing, extensive use of various smart IC card, civilian luxury car security system, video recorder, camera, fully automatic washing machine control, and program-controlled toys,

30、 electr</p><p>　　1. In the application of Intelligent InstrumentsSCM has a small size, low power consumption, controlling function, expansion flexibility, the advantages of miniaturization and ease of use, w

31、idely used instrument, combining different types of sensors can be realized Zhuru voltage, power, frequency, humidity, temperature, flow, speed, thickness, angle, length, hardness, elemental, physical pressure measuremen

32、t. SCM makes use of digital instruments, intelligence, miniaturization, and functionality </p><p>　　2. In the industrial control applicationWith the MCU can constitute a variety of control systems, data acqu

33、isition system. Such as factory assembly line of intelligent control</p><p>　　3. In Household Appliances Can be said that the appliances are basically using SCM, praise from the electric rice, washing machin

34、es, refrigerators, air conditioners, color TV, and other audio video equipment, to the electronic weighing equipment, varied, and omnipresent. 4. In the field of computer networks and communications applications MCU

35、general with modern communication interface, can be easy with the computer data communication, networking and communications in computer applications b</p><p>　　5. Microcomputer in the field of medical devic

36、e applications SCM in the use of medical devices is also quite extensive, such as medical respirator, the various analyzers, monitors, ultrasound diagnostic equipment and hospital beds, etc. call system. 6. In a vari

37、ety of major appliances in the modular applications Designed to achieve some special single specific function to be modular in a variety of circuit applications, without requiring the use of personnel to understand its i

38、nternal struct</p><p>　　Application of six important part of learning MCU learning an important part of the six applications 1, Bus: We know that a circuit is always made by the devices connected by wires, i

39、n analog circuits, the connection does not become a problem because the device is a serial relationship between the general, the device is not much connection between the , but the computer is not the same circuit, it is

40、 a microprocessor core, the device must be connected with the microprocessor, the device must be </p><p>　　Second, data, address, command: The reason why these three together because of the nature of these t

41、hree are the same - the number, or are a string of '0 'and '1' form the sequence. In other words, addresses, instructions are also data. Instruction: from single chip designer provides a number of commonl

42、y used instructions with mnemonic we have a strict correspondence between the developer can not be changed by the MCU. Address: the search for MCU internal, external storage units, input and outpu</p><p>　　F

43、ourth, the program's implementation: Reduction in power after the 8051 microcontroller within the program counter (PC) in the value of 0000 ', the process is always from the 0000' units started, that is: the

44、system must exist in ROM 0000 'this unit , and in 0000 'unit must be stored in a single instruction. 5, the stack: Stack is a region, is used to store data, there is no special about the region itself is a pa

45、rt of internal RAM, special access to its data storage and the way that the so-</p><p><b>　　外文文獻(xiàn)翻譯：</b></p><p><b>　　單片機(jī)介紹</b></p><p>　　單片機(jī)也被稱為微控制器（Microcontr

46、oller Unit），常用英文字母的縮寫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的專用處理器發(fā)展而來。最早的設(shè)計理念是通過將大量外圍設(shè)備和CPU集成在一個芯片中，使計算機(jī)系統(tǒng)更小，更容易集成進(jìn)復(fù)雜的而對體積要求嚴(yán)格的控制設(shè)備當(dāng)中。INTEL的Z80是最早按照這種思想設(shè)計出的處理器，從此以后，單片機(jī)和專用處理器的發(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

47、中最成功的是INTEL的8031，因為簡單可靠而性能不錯獲得了很大的好評。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，開始出現(xiàn)了16位單片機(jī)，但因為性價比不理想并未得到很廣泛的應(yīng)用。90年代后隨著消費電子產(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

48、市場。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300MHz，性能直追90年代中期的專用處理器，而普通的型號出廠價格跌落至1美元，最高端[1]的型號也只有10美元。當(dāng)代單片機(jī)系統(tǒng)已經(jīng)不再只在裸機(jī)環(huán)境下開發(fā)和使用，大量專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用的Windows和Linux操作系統(tǒng)。 &

49、lt;/p><p>　　單片機(jī)比專用處理器更適合應(yīng)用于嵌入式系統(tǒng)，因此它得到了最多的應(yīng)用。事實上單片機(jī)是世界上數(shù)量最多的計算機(jī)。現(xiàn)代人類生活中所用的幾乎每件電子和機(jī)械產(chǎn)品中都會集成有單片機(jī)。手機(jī)、電話、計算器、家用電器、電子玩具、掌上電腦以及鼠標(biāo)等電腦配件中都配有1-2部單片機(jī)。而個人電腦中也會有為數(shù)不少的單片機(jī)在工作。汽車上一般配備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)百臺單片機(jī)在同時工作！單片機(jī)的數(shù)量不

50、僅遠(yuǎn)超過PC機(jī)和其他計算的總和，甚至比人類的數(shù)量還要多。 </p><p>　　單片機(jī)又稱單片微控制器,它不是完成某一個邏輯功能的芯片,而是把一個計算機(jī)系統(tǒng)集成到一個芯片上。相當(dāng)于一個微型的計算機(jī)，和計算機(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計算機(jī)。它的體積小、質(zhì)量輕、價格便宜、為學(xué)習(xí)、應(yīng)用和開發(fā)提供了便利條件。同時，學(xué)習(xí)使用單片機(jī)是了解計算機(jī)原理與結(jié)構(gòu)的最佳選擇。 </p>

51、<p>　　單片機(jī)內(nèi)部也用和電腦功能類似的模塊，比如CPU，內(nèi)存，并行總線，還有和硬盤作用相同的存儲器件，不同的是它的這些部件性能都相對我們的家用電腦弱很多，不過價錢也是低的，一般不超過10元即可......用它來做一些控制電器一類不是很復(fù)雜的工作足矣了。我們現(xiàn)在用的全自動滾筒洗衣機(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

52、是一種在線式實時控制計算機(jī)，在線式就是現(xiàn)場控制，需要的是有較強(qiáng)的抗干擾能力，較低的成本，這也是和離線式計算機(jī)的（比如家用PC）的主要區(qū)別。 </p><p><b>　　單片機(jī)芯片</b></p><p>　　單片機(jī)是靠程序運行的，并且可以修改。通過不同的程序?qū)崿F(xiàn)不同的功能，尤其是特殊的獨特的一些功能，這是別的器件需要費很大力氣才能做到的，有些則是花大力氣也很難做到

53、的。一個不是很復(fù)雜的功能要是用美國50年代開發(fā)的74系列，或者60年代的CD4000系列這些純硬件來搞定的話，電路一定是一塊大PCB板！但是如果要是用美國70年代成功投放市場的系列單片機(jī)，結(jié)果就會有天壤之別！只因為單片機(jī)的通過你編寫的程序可以實現(xiàn)高智能，高效率，以及高可靠性！ </p><p>　　由于單片機(jī)對成本是敏感的，所以目前占統(tǒng)治地位的軟件還是最低級匯編語言，它是除了二進(jìn)制機(jī)器碼以上最低級的語言了，既然這

54、么低級為什么還要用呢？很多高級的語言已經(jīng)達(dá)到了可視化編程的水平為什么不用呢？原因很簡單，就是單片機(jī)沒有家用計算機(jī)那樣的CPU，也沒有像硬盤那樣的海量存儲設(shè)備。一個可視化高級語言編寫的小程序里面即使只有一個按鈕，也會達(dá)到幾十K的尺寸！對于家用PC的硬盤來講沒什么，可是對于單片機(jī)來講是不能接受的。 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，如果把巨型計算機(jī)上的操作系統(tǒng)和應(yīng)用軟件拿到家用PC上來運

55、行，家用PC的也是承受不了的。 </p><p>　　可以說，二十世紀(jì)跨越了三個“電”的時代，即電氣時代、電子時代和現(xiàn)已進(jìn)入的電腦時代。不過，這種電腦，通常是指個人計算機(jī)，簡稱PC機(jī)。它由主機(jī)、鍵盤、顯示器等組成。還有一類計算機(jī)，大多數(shù)人卻不怎么熟悉。這種計算機(jī)就是把智能賦予各種機(jī)械的單片機(jī)（亦稱微控制器）。顧名思義，這種計算機(jī)的最小系統(tǒng)只用了一片集成電路，即可進(jìn)行簡單運算和控制。因為它體積小，通常都藏在被控機(jī)械

56、的“肚子”里。它在整個裝置中，起著有如人類頭腦的作用，它出了毛病，整個裝置就癱瘓了?，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、實時工控、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)品升級換代的功效，常在產(chǎn)品名稱前冠以形容詞——“智能型”，如智能型洗衣機(jī)等。現(xiàn)在有些工廠的技術(shù)人員或其它業(yè)余電子開發(fā)者搞出來的某些產(chǎn)品，不是電路太復(fù)雜，就是功能太簡單且極易被仿制。究其原因，可能就卡在產(chǎn)品未使用單片機(jī)或其它可編

57、程邏輯器件上。 </p><p><b>　　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><p><b>　　起初模型</b></p><p>　　1.SCM即單片微型計算機(jī)（Single Chip Microcomput

58、er）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)?！皠?chuàng)新模式”獲得成功，奠定了SCM與通用計算機(jī)完全不同的發(fā)展道路。在開創(chuàng)嵌入式系統(tǒng)獨立發(fā)展道路上，Intel公司功不可沒。 </p><p>　　2.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足嵌入式應(yīng)用時，對象系統(tǒng)要求的各種外圍電路與接口電路，突顯其對象的智能化控制能力。它所涉及的領(lǐng)域都與對象

59、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)廠家。從這一角度來看，Intel逐漸淡出MCU的發(fā)展也有其客觀因素。在發(fā)展MCU方面，最著名的廠家當(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，將MCS-51從單片微型計算機(jī)迅速發(fā)展到微控制器。因此，當(dāng)我們回顧嵌入式系統(tǒng)發(fā)展道路時，不要忘記Intel和Philips的歷史功績。 </p>

60、<p><b>　　嵌入式系統(tǒng)</b></p><p>　　單片機(jī)是嵌入式系統(tǒng)的獨立發(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，專用單片機(jī)的發(fā)展自然形成了SoC化趨勢。隨著微電子技術(shù)、IC設(shè)計、EDA工具的發(fā)展，基于SoC的單片機(jī)應(yīng)用系統(tǒng)設(shè)計會有較大的發(fā)展。因此，對單片機(jī)的理解可以從單片微型計算機(jī)、單片微控制器延伸到單片應(yīng)用系統(tǒng)。 </p

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

62、單片機(jī)。更不用說自動控制領(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)、開發(fā)與應(yīng)用將造就一批計算機(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、專用設(shè)備的智能化管理及過程控制等領(lǐng)域，大致可分如下幾個范疇： </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

63、小、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，廣泛應(yīng)用于儀器儀表中，結(jié)合不同類型的傳感器，可實現(xiàn)諸如電壓、功率、頻率、濕度、溫度、流量、速度、厚度、角度、長度、硬度、元素、壓力等物理量的測量。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。例如精密的測量設(shè)備（功率計，示波器，各種分析儀）。 </p><p>　　2.在工業(yè)控制中的應(yīng)用 </p>&

64、lt;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)。例如工廠流水線的智能化管 </p><p>　　3.在家用電器中的應(yīng)用 </p><p>　　可以這樣說，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，無所不在。 </p><p>　　4.在計算機(jī)網(wǎng)絡(luò)和通信領(lǐng)域中的

65、應(yīng)用 </p><p>　　現(xiàn)代的單片機(jī)普遍具備通信接口，可以很方便地與計算機(jī)進(jìn)行數(shù)據(jù)通信，為在計算機(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)備基本上都實現(xiàn)了單片機(jī)智能控制，從手機(jī)，電話機(jī)、小型程控交換機(jī)、樓宇自動通信呼叫系統(tǒng)、列車無線通信、再到日常工作中隨處可見的移動電話，集群移動通信，無線電對講機(jī)等。 </p><p>　　5.單片機(jī)在醫(yī)用設(shè)備領(lǐng)域中的應(yīng)用 </p

66、><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>　　某些專用單片機(jī)設(shè)計用于實現(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)。如音樂集成單片機(jī)，看似簡單的功能，微縮在純電子芯片中（有別于磁帶機(jī)的原理）

67、，就需要復(fù)雜的類似于計算機(jī)的原理。如：音樂信號以數(shù)字的形式存于存儲器中（類似于ROM），由微控制器讀出，轉(zhuǎn)化為模擬音樂電信號（類似于聲卡）。 </p><p>　　在大型電路中，這種模塊化應(yīng)用極大地縮小了體積，簡化了電路，降低了損壞、錯誤率，也方便于更換。 </p><p>　　7.單片機(jī)在汽車設(shè)備領(lǐng)域中的應(yīng)用 </p><p>　　單片機(jī)在汽車電子中的應(yīng)用非常廣泛

68、，例如汽車中的發(fā)動機(jī)控制器，基于CAN總線的汽車發(fā)動機(jī)智能電子控制器，GPS導(dǎo)航系統(tǒng)，abs防抱死系統(tǒng)，制動系統(tǒng)等等。 </p><p>　　此外，單片機(jī)在工商，金融，科研、教育，國防航空航天等領(lǐng)域都有著十分廣泛的用途。 </p><p>　　學(xué)習(xí)應(yīng)用六大重要部分</p><p>　　單片機(jī)學(xué)習(xí)應(yīng)用的六大重要部分 </p><p><b

69、>　　一、總線：</b></p><p>　　我們知道，一個電路總是由元器件通過電線連接而成的，在模擬電路中，連線并不成為一個問題，因為各器件間一般是串行關(guān)系，各器件之間的連線并不很多，但計算機(jī)電路卻不一樣，它是以微處理器為核心，各器件都要與微處理器相連，各器件之間的工作必須相互協(xié)調(diào)，所以需要的連線就很多了，如果仍如同模擬電路一樣，在各微處理器和各器件間單獨連線，則線的數(shù)量將多得驚人，所以在微處

70、理機(jī)中引入了總線的概念，各個器件共同享用連線，所有器件的8根數(shù)據(jù)線全部接到8根公用的線上，即相當(dāng)于各個器件并聯(lián)起來，但僅這樣還不行，如果有兩個器件同時送出數(shù)據(jù)，一個為0，一個為1，那么，接收方接收到的究竟是什么呢？這種情況是不允許的，所以要通過控制線進(jìn)行控制，使器件分時工作，任何時候只能有一個器件發(fā)送數(shù)據(jù)（可以有多個器件同時接收）。器件的數(shù)據(jù)線也就被稱為數(shù)據(jù)總線，器件所有的控制線被稱為控制總線。在單片機(jī)內(nèi)部或者外部存儲器及其它器件中有存

71、儲單元，這些存儲單元要被分配地址，才能使用，分配地址當(dāng)然也是以電信號的形式給出的，由于存儲單元比較多，所以，用于地址分配的線也較多，這些線被稱為地址總線。 </p><p>　　二、數(shù)據(jù)、地址、指令：</p><p>　　之所以將這三者放在一起，是因為這三者的本質(zhì)都是一樣的——數(shù)字，或者說都是一串‘0’和‘1’組成的序列。換言之，地址、指令也都是數(shù)據(jù)。指令：由單片機(jī)芯片的設(shè)計者規(guī)定的一種數(shù)

72、字，它與我們常用的指令助記符有著嚴(yán)格的一一對應(yīng)關(guān)系，不可以由單片機(jī)的開發(fā)者更改。地址：是尋找單片機(jī)內(nèi)部、外部的存儲單元、輸入輸出口的依據(jù)，內(nèi)部單元的地址值已由芯片設(shè)計者規(guī)定好，不可更改，外部的單元可以由單片機(jī)開發(fā)者自行決定，但有一些地址單元是一定要有的（詳見程序的執(zhí)行過程）。 </p><p>　　三、P0口、P2口和P3的第二功能用法：</p><p>　　初學(xué)時往往對P0口、P2口和P

73、3口的第二功能用法迷惑不解，認(rèn)為第二功能和原功能之間要有一個切換的過程，或者說要有一條指令，事實上，各端口的第二功能完全是自動的，不需要用指令來轉(zhuǎn)換。如P3.6、P3.7分別是WR、RD信號，當(dāng)微片理機(jī)外接RAM或有外部I/O口時，它們被用作第二功能，不能作為通用I/O口使用，只要一微處理機(jī)一執(zhí)行到MOVX指令，就會有相應(yīng)的信號從P3.6或P3.7送出，不需要事先用指令說明。事實上‘不能作為通用I/O口使用’也并不是‘不能’而是（使用者

74、）‘不會’將其作為通用I/O口使用。你完全可以在指令中按排一條SETB P3.7的指令，并且當(dāng)單片機(jī)執(zhí)行到這條指令時，也會使P3.7變?yōu)楦唠娖剑褂谜卟粫@么去做，因為這通常會導(dǎo)致系統(tǒng)的崩潰。</p><p>　　四、程序的執(zhí)行過程：</p><p>　　單片機(jī)在通電復(fù)位后8051內(nèi)的程序計數(shù)器（PC）中的值為‘0000’，所以程序總是從‘0000’單元開始執(zhí)行，也就是說：在系統(tǒng)的ROM

75、中一定要存在‘0000’這個單元，并且在‘0000’單元中存放的一定是一條指令。 </p><p><b>　　五、堆棧：</b></p><p>　　堆棧是一個區(qū)域，是用來存放數(shù)據(jù)的，這個區(qū)域本身沒有任何特殊之處，就是內(nèi)部RAM的一部份，特殊的是它存放和取用數(shù)據(jù)的方式，即所謂的‘先進(jìn)后出，后進(jìn)先出’，并且堆棧有特殊的數(shù)據(jù)傳輸指令，即‘PUSH’和‘POP’，有一個特

76、殊的專為其服務(wù)的單元，即堆棧指針SP，每當(dāng)執(zhí)一次PUSH指令時，SP就（在原來值的基礎(chǔ)上）自動加1，每當(dāng)執(zhí)行一次POP指令，SP就（在原來值的基礎(chǔ)上）自動減1。由于SP中的值可以用指令加以改變，所以只要在程序開始階段更改了SP的值，就可以把堆棧設(shè)置在規(guī)定的內(nèi)存單元中，如在程序開始時，用一條MOV SP，#5FH指令，就時把堆棧設(shè)置在從內(nèi)存單元60H開始的單元中。一般程序的開頭總有這么一條設(shè)置堆棧指針的指令，因為開機(jī)時，SP的初始值為07

77、H，這樣就使堆棧從08H單元開始往后，而08H到1FH這個區(qū)域正是8031的第二、三、四工作寄存器區(qū)，經(jīng)常要被使用，這會造成數(shù)據(jù)的混亂。不同作者編寫程序時，初始化堆棧指令也不完全相同，這是作者的習(xí)慣問題。當(dāng)設(shè)置好堆棧區(qū)后，并不意味著該區(qū)域成為一種專用內(nèi)存，它還是可以象普通內(nèi)存區(qū)域一樣使用，只是一般情況下編程者不會把它當(dāng)成普通內(nèi)存用了。</p><p><b>　　DS18B20資料</b>&

78、lt;/p><p><b>　　外文文獻(xiàn)原文：</b></p><p>　　DS18B20 Programmable Resolution 1-Wire</p><p>　　Digital Thermometer</p><p>　　1、DS18B20 FEATURES </p><p>　　Uniq

79、ue 1-Wire interface requires only one Port pin for communication, requires no external components </p><p>　　Each device has a unique 64-bit serial code stored in an onboard ROM </p><p>　　Can be

80、powered form data line .Power supply range is 3.0Vto 5.5V </p><p>　?。?）Measures temperatures form -55℃ to +125℃ , ±0.5℃ accuracy from -10℃ to +85℃ </p><p>　　（5）Thermometer resolution is use

81、r-selected from 9 to 12 bits </p><p>　?。?）Converts temperature to 12-bit digital word in 750ms (max) </p><p>　?。?）Alarm search command identifies and addresses devices whose temperature is outsi

82、de of programmed limits (temperature alarm condition) </p><p>　　（8） Available in 8-pin SOIC, and 3-bin TO -92 packages</p><p>　　2、DS18B20 BLOCK DIAFRAM 、</p><p>　　Figure 1 shows a b

83、lock diagram of the DS18B20, The 64-bite ROM stores the device’s serial code. The scratchpad memory contains the 2-byte temperature egister that stores the digital output from the temperature sensor. In addition, the scr

84、atchpad provides access to the 1-byte upper and lower alarm trigger register (TH and TL), and the 1-byte configuratuion register. The configuration register allows the user to set the resolution of the temperature-to-dig

85、ital conversion to 9, 10, 11 or 12 bits. T</p><p>　　Figure 1 block diagram of the DS18B20</p><p>　　3、DS18B20 ROM COMMANDS 、 </p><p>　　SEARCH ROM [0F0H] </p><p>　　When a

86、 system is initially powered up, the master must identify the ROM codes of all slave devices on the bus, which allows the master to determine the number of slaves and their device types. The master learns the ROM codes t

87、hrough a process of elimination that requires the master to perform a Search ROM cycle as many times as necessary to identify all of the slave’s 64-bit ROM devices. </p><p>　　READ ROM [55H] </p><p

88、>　　This command can only be used when there is one slave on the bus. It allows the bus master to read the slave`64-bit ROM code without using the Search ROM procedure. If this command is used when there is more than o

89、ne slave present on the bus, a data collision will occur when all the slaves attempt to respond at the same time.</p><p>　　(3)MATCH ROM [55H] </p><p>　　The match ROM command followed by a 64-bit

90、 ROM code sequence allows the bus master to address a specific DS18B20 on a multidrop or single-drop bus. Only the DS18B20 that exactly matches the 64-bitROM code sequence will respond to the function command issued by

91、the master; all other slaves on the bus will wait for a reset pulse. </p><p>　　SKIP ROM [0CCH] </p><p>　　The master can use this command to address all devices on the bus simultaneously without

92、sending out any ROM code information. Note that the Read Scratchpad command can follow the Skip ROM command only if there is a single slave device on the bus. In this case time is saved by allowing the master to read fro

93、m the slave without sending the device’s 64-bit ROM code. A Skip ROM command followed by a Read Scratchpad command will cause a data collision on the bus if there is more than one slave since</p><p>　　ALARM

94、SEARCH [0ECH] </p><p>　　The operation of this command is identical to the operation of the Search ROM command except that only slaves with a set alarm flag will respond .This command allows the master device

95、 to determine if anyDS18B20s experienced an alarm condition during the most recent temperature conversion .Refer to the OPERATION-ALARM SIGNAING section for an explanation of alarm flag operation. </p><p>　　

96、CONVERTT [44H] </p><p>　　This command initiates a single temperature conversion. Following the conversion, the resulting thermal data is stored in the 2-bute temperature register in the scratchpad memory and

97、 the DS18B20 returns to its low-power idle state. If the device is being used in parasite power mode, within 10us after this command is issued the master must enable a strong pullup on the 1-Wire bus for the duration of

98、the conversion as described in the POWERING THE DS18320 section. If the DS18B20 is powered by an e</p><p>　　WRITE SCRACHPAD [4EH] </p><p>　　This command allows the master to write 3 bytes of the

99、 data to the DS18B20’s scratchpad. The first data byte is writer into the TH register , the second byte is written into the TL register, and the third byte is written into the configuration register. Data must be transmi

100、tted least significant bit first. All three bytes must be written before the master issues a reset ,or the data may be corrupted. </p><p>　　READ SCRACHPAD [0BEH]</p><p>　　This command allows the

101、 master to read the contents of the scratchpad .The data transfer starts with the least significant bit of byte 0 and continues through the scratchpad until 9 byte(byte 8-CRC) is read.The master may issue a reset to term