机电专业英语第2版19unit 19

1、LOGO单单 片片 机机 介介 绍绍 徐存善主编 徐存善主编 徐存善主编 Microcontrollers are hidden inside a surprising number of products these days (Fig.19.1). About 55% of all CPUs sold in the world are 8-bit microcontrollers. If your microwave oven has an LED or LCD screen and a keypad, it contains a microcontroller. All modem au

2、tomobiles contain at least one microcontroller, and can have as many as six or seven: The engine is controlled by a microcontroller, as are the anti-lock brakes and so on 1 . Any device that has a remote control almost certainly contains a microcontroller: TVs, VCRs and high-end stereo systems all f

3、all into this category 2 . Digital cameras, cell phones, camcorders, answering machines, laser printers, telephones (the ones with caller ID, 20-number memory, etc.), pagers, and refrigerators, dishwashers, washers and dryers (the ones with displays and keypads) You get the idea. Basically, any prod

4、uct or device that interacts with its user has a microcontroller buried inside 3 . 徐存善主编Fig.19-1 Products containing a microcontroller 徐存善主编 What is Microcontroller A microcontroller (also MCU or C) is a computer system-on-a-chip, containing a processor, memory, and input/output functions. It is a m

5、icroprocessor emphasizing high integration, in contrast to a general-purpose microprocessor (the kind used in a PC) 4 . In addition to the usual arithmetic and logic elements of a general purpose microprocessor, the microcontroller integrates additional elements such as read-write memory for data st

6、orage, read-only memory for program storage, EEPROM for permanent data storage, peripheral devices, and input/output interfaces. At clock speeds of as little as a few MHz or even lower, microcontrollers often operate at very low speed compared to modern day microprocessors, but this is adequate for

7、typical applications. They consume relatively little power (milliwatts), and will generally have the ability to sleep while waiting for a peripheral event such as a button press to wake them up again to do something. Power consumption while sleeping may be just nanowatts, making them ideal for low p

8、ower and long lasting battery applications 5 . 徐存善主编Intel 8051The Intel 8051 is a Harvard architecture, single chip microcontroller (C) which was developed by Intel in 1980 for use in embedded systems.Intels original 8051 family was developed using NMOS technology, but later versions, identified by

9、a letter “C” in their name, e.g. 80C51, used CMOS technology and were less power-hungry than their NMOS predecessors 6 - this made them eminently more suitable for battery-powered devices. 徐存善主编The 8051 families have following important features (Fig.19.2):(1) 8-bit data bus - It can access 8 bits o

10、f data in one operation (hence it is an 8-bit microcontroller).(2) 16-bit address bus - It can access 216 memory locations - 64KB each of RAM and ROM.(3) On-chip RAM - 128 bytes (“Data Memory”).(4) On-chip ROM - 4KB (“Program Memory”).(5) Four byte bi-directional inputoutput port. (6) UART (serial p

11、ort).(7) Two 16-bit Counter/timers.(8) Two-level interrupt priority.(9) Power saving mode. 徐存善主编Fig.19-2 Important features in 8501 families 徐存善主编 A particularly useful feature of the 8051 core is the inclusion of a Boolean processing engine which allows bit-level Boolean logic operations to be carr

12、ied out directly and efficiently on internal registers and RAM. This feature helped to cement the 805ls popularity in industrial control applications. Another valued feature is that it has four separate register sets, which can be used to greatly reduce interrupt latency compared to the more common

13、method of storing interrupt context on a stack. The original 8051 core ran at 12 clock cycles per machine cycle, with most instructions executing in one or two machine cycles. With a 12 MHz clock frequency, the 8051 could thus execute 1 million one-cycle instructions per second or 500 000 two-cycle

14、instructions per second. Enhanced 8051 cores are now commonly used which run at six, four, two, or even one clock per machine cycle, and have clock frequencies of up to 100 MHz, and are thus capable of an even greater number of instructions per second. 徐存善主编 Common features included in modern 8051 b

15、ased microcontroller includebuilt-in reset timers with brown-out detection, on-chip oscillators, self programmable Flash ROM program memory, boot loader code in ROM, EEPROM non-volatile data storage, IC, SPI, and USB host interfaces, PWMgenerators, analog comparators, A/D and D/A converters, extra c

16、ounters andtimers, in-circuit debugging facilities, more interrupt sources,and extra powersaving modes. 徐存善主编microcontroller ,maikrukntrul n. 微控制器，微控器，单片机camcorder kmk:d n. 摄录像机；便携式摄像机display ,displei n. 显示器，指示器；陈列，展览vt. 展示；显示integration ,intirein n. 集成；综合；集中arithmetic rimtik n. 算术，算法；运算permanent p:

17、mnnt adj. 永久的，永恒的；不变的peripheral prifrl adj. 外围的；外设的；次要的n. 外围设备eminently eminntli adv. 突出地；显著地access kses vt. 使用；存取，访问；接近 n. 进入；使用权 徐存善主编cement siment vt. 巩固，加强；(用水泥等)粘合 n. 水泥latency leitnsi n. 等待时间，延迟，潜伏期stack stk n. 堆；堆叠；存储栈，堆栈non-volatile nn,vltail adj. 非易失的；不挥发的debug di:b vt. 调试；排除故障 n. 调试器，排错器fa

18、ll into 落入；分成，归入，属于；开始（某事）interacts with 与相互影响或作用in contrast to 与对比(或对照)；与相反 徐存善主编 1. The engine is controlled by a microcontroller, as are the anti-lock brakes and so on. 译文：发动机、防抱死制动系统等等都是用单片机控制的。 说明：句中anti-lock brake 表示防抱死制动系统或防锁死煞车系统，可安装在任何带液压刹车的汽车上，能避免在紧急刹车时方向失控及车轮侧滑。“as” is a substitute for a

19、clause，and it can be replaced by “so” (也一样)，e.g. 1) She is a doctor, as/so is her husband. 她和她丈夫都是医生。 2) Business confidence has picked up, as/so has the Paris Bourse. 商业信心有所提升，巴黎证券交易所的交易情况也有好转。Language points 徐存善主编 2. Any device that has a remote control almost certainly contains a microcontroller:

20、 TVs, VCRs and high-end stereo systems all fall into this category. 译文：任何具有远程遥控的设备都几乎肯定包含一部单片机：电视机、录像机、高端立体声音响系统都属于这一类。 说明：“that” is a relative pronoun used to introduce an attributive clause modifying “device”. “fall into” means “be included in or classified as, belong to” (归入，属于，分成；陷入), e.g. 1) Go

21、ing forward, these cases will fall into five distinct categories. 接下来，这些案件将被归入五大类别。 2) Old civilization may fall into decay. 古老的文化可能会渐渐衰落下去。Language points 徐存善主编 3. Basically, any product or device that interacts with its userhas a microcontroller buried inside. 译文：任何与用户进行互动的产品或设备内部都嵌有单片机。 说明：“that”

22、 is a relative pronoun used to introduce anattributive clause. “buried inside” is a past participle phrasemodifying “microcontroller”. “interact with” means “act togetherwith others” (与互动或相互作用), e.g. But because these particles are electrically charged, they alsointeract with the Earths magnetic fie

23、ld. 但是因为这些粒子是带电的，所以它们会受地球磁场的影响。Language points 徐存善主编 4. It is a microprocessor emphasizing high integration, in contrast to ageneral-purpose microprocessor (the kind used in a PC). 译文：与应用在个人电脑中的通用型微处理器相比，它是高度集成的微处理器。 说明: “emphasizing high integration” is a present participle phrase used asan attribu

24、te modifying “microprocessor”. “in contrast to” means “与对比(或对照)；与相反” 1) The gaiety and lightness of his work were in contrast to his own sad nature. 他的作品的欢乐与轻快与他哀伤的性格形成鲜明的对照。 2) In contrast to her elder brother, she was always considerate in her treatment of others. 和她哥哥完全不一样，她对别人总是很体贴。Language poin

25、ts 徐存善主编5. Power consumption while sleeping may be just nanowatts, making them ideal for low power and long lasting battery applications.译文：睡眠时消耗功率可能只有纳瓦级(109 W)，所以很适宜应用在低功耗且长期用电池供电的场合。说明：句中连词while表示“当的时候”。现在分词sleeping作时间状语，相当于一个时间状语从句。making them ideal for low power and long lasting battery applica

26、tions是现在分词短语，作结果状语。be ideal for表示“对很理想，适用于” e.g.1) The cable system is ideal for spanning natural barriers of wide rivers, deep valleys, or ravines.这种钢索体系是跨越宽河道、深丘谷或深山谷天然障碍物的理想体系。2) Unlike incandescent or fluorescent lamps, which spew light in all directions, LEDs generate directional light, making

27、them ideal for selectively illuminating areas. 不像白炽灯或者荧光灯那样灯光四射，LED产生的是定向光，定点照明的理想之选。 Language points 徐存善主编 6. Intels original 8051 family was developed using NMOS technology, but laterversions, identified by a letter “C” in their name, e.g. 80C51, used CMOS technologyand were less power-hungry than

28、 their NMOS predecessors. 译文：英特尔最早的805l系列是用NMOS技术开发的，但后来的标以“C”字母如80C51的版本是用CMOS技术开发的芯片。 说明：句中现在分词短语using NMOS technology作方式状语。过去分词短语identified by a letter “C” in their name作定语修饰later versions，相当于一个定语从句。power-hungry表示“高耗电的” e.g. The new lines will be used to carry electricity from coal-rich inland pr

29、ovinces to the power-hungry coast. 新输电线路将用于连接中国煤炭资源丰富的内陆省份和电力短缺的沿海地区。 Language points 徐存善主编 I. Answer the following questions.1. How many kinds of products or devices embedded with a microcontroller are listed in the first paragraph? What are they？2. What is referred to as a microcontroller? Sixteen

30、 kinds of products or devices are listed. They are microwave ovens, modem automobiles, TVs, VCRs, high-end stereo systems, digital cameras, cell phones, camcorders, answering machines, laser printers, telephones (the ones with caller ID, 20-number memory, etc.), pagers, and refrigerators, dishwasher

31、s, washers and dryers (the ones with displays and keypads).A microcontroller is a computer system-on-a-chip, containing a processor, memory, and input/output functions.Exercises 徐存善主编 I. Answer the following questions.3. What are the major differences between the microcontroller and the general-purp

32、ose microprocessor used in a PC?4. What are the two particularly useful features of the 8051 core? In contrast to a general-purpose microprocessor, the microcontroller integrates additional elements such as read-write memory for data storage, read-only memory for program storage, EEPROM for permanen

33、t data storage, peripheral devices, and input/output interfaces.The two particularly useful features of the 8051 core are the inclusion of a Boolean processing engine and four separate register sets.Exercises 徐存善主编II. Mark the following statements with T (true) or F (false) according to the text.1.

34、The majority of microcontrollers in use today are embedded in other machinery, which are called embedded systems.2. The high integration of the microcontroller drastically reduces the number of chips and the amount of wiring and circuit board space.3. By reducing the size and cost compared to a desi

35、gn that uses separate elements, microcontrollers make it economical to digitally control even more devices and processes.TTTExercises 徐存善主编II. Mark the following statements with T (true) or F (false) according to the text.4. Microcontrollers operate at very low speed, so their applications are very

36、limited.5. The Intel 80C51 family consumes less power than the original 8051 family.6. Because the 8051 core contains four separate register sets, it is widely used in industrial control.FTFExercises 徐存善主编1.防抱死制动系统 2.可储存数据的读写存储器 3.通用微处理机 4.两级中断优先权 III. Translate the following phrases and sentences i

37、nto English. anti-lock brakes read-write memory for data storage general-purpose microprocessor two-level interrupt priorityExercises 徐存善主编 III. Translate the following phrases and sentences into English.5. 微控制器是指一个集成在一块芯片上的计算机系统，它有 处理器、存储器和输入输出功能。A microcontroller is a computer system-on-a-chip, co

38、ntaining a processor，memory, and input/output functions. 徐存善主编 1结合具体语言环境了解全句大意。 2剖析全句，分清主要成分和次要成分，主句和从句。 3紧缩主干，确定句子的主、谓语，找出句子的基本构架，及其所属句型。 4疏通脉络，清理枝蔓，分清主次关系，注意上下层次，前后引衬及其逻辑关系。 5按汉语造句的规律，进行选词和语序的调整。 6反复研究译文，进行词句锤炼的润饰工夫，最后定稿。 Sample: For a family of four, for example, it is more convenient as well as

39、cheaper to sit comfortably at home, with almost unlimited entertainment available, than to go out in search of amusement elsewhere 分析：该句的骨干结构为“it is moreto do sth than to do sth else”是一个比较结构，而且是在两个不定式之间进行比较；该句中共有三个谓语结构，它们之间的关系为：it is more convenient as well as cheaper to为主体结构，但it是形式主语，真正的主语为第二个谓语结构：

40、to sit comfortably at home，并与第三个谓语结构to go out in search of amusement elsewhere作比较。 综合上述翻译方法，这个句子我们可以翻译为：譬如，对于一个四口之家来说，舒舒服服地在家中看电视，就能看到几乎数不清的娱乐节目，这比到外面别的地方去消遣又便宜又方便。 徐存善主编1顺译法顺译法 顺译法就是按照原文时间、方位、逻辑等顺序将长句的内容再现，例如： Even when we turn off the beside lamp and are fast asleep, electricity is working for us,

41、 driving our refrigerators, heating our water, or keeping our rooms air-conditioned. 分析：该句子由一个主句、三个作伴随状语的现在分词以及位于句首的时间状语从旬组成，共有五层意思：A即使在我们关掉了床头灯深深地进入梦乡时；B电仍在为我们工作；C帮我们开动电冰箱；D加热水；E或是室内空调机继续运转。上述五层意思的逻辑关系以及表达的顺序与汉语完全一致，因此，我们可以通过顺序法，译为： 即使在我们关掉了床头灯深深地进入梦乡时，电仍在为我们工作；帮我们开动电冰加热，或使室内空调机继续运转。 徐存善主编2倒译法倒译法 在

42、翻译有些长句时，要想使译文通顺、符合汉语表达习惯，翻译时必须从后往前译，这就是倒译法。譬如： It therefore becomes more and more important that, if students are not to waste their opportunities, there will have to be much more detailed information about courses and more advice. 因此，如果要使学生充分利用他们（上大学）的机会，就得为他们提供大量关于课程的更为详尽的信息，作更多的指导。这个问题显得越来越重要。 徐存

43、善主编3分译法分译法 分译法是将长句拆开来，将其中从句或短语译成短句，分开来叙述，如: Television, it is often said, keeps one informed about current events, allows one to follow the latest developments in science and politics, and offers an endless series of programs which are both instructive and entertaining. 分析：在此长句中，有一个插入语“it is often s

44、aid”，三个并列的谓语结构，还有一个定语从句，这三个并列的谓语结构尽管在结构上同属于同一个句子，但都有独立的意义，因此在翻译时，可以采用分句法，按照汉语的习惯把整个句子分解成几个独立的分句，此句可译为：人们常说，通过电视可以了解时事，掌握科学和政治的最新动态。从电视里还可以看到层出不穷、既有教育意义又有娱乐性的新节目。 徐存善主编4综合法综合法 要求我们把各种方法综合使用，先仔细分析，或按照时间的先后，或按照逻辑顺序，顺逆结合，主次分明地对全句进行综合处理，以便把英语原文翻译成通顺的汉语句子。例如： People were afraid to leave their houses, for

45、although the police had been ordered to stand by in case of emergency, they were just as confused and helpless as anybody else. 尽管警察已接到命令，要作好准备以应付紧急情况，但人们不敢出门，因为警察也和其他人一样不知所措和无能为力。力。 徐存善主编An assembler is a software tool designed to simplify the task of writing computer programs.1 It translates symbo

46、lic code into executable object code. This object code may then be programmed into a microcontroller and executed. Assembly language programs translate directly into CPU instructions which instruct the processor what operations to perform. Therefore, to effectively write assembly programs, you shoul

47、d be familiar with both the microcomputer architecture and the assembly language.汇编程序是什么？汇编程序是什么？ 汇编程序是一种用来简化计算机编写程序的软件工具。汇编程序把符号化的代码（汇编指令）编译成可执行的目标代码（机器指令），然后把该目标代码编入单片机（的程序存储器）中并加以执行。汇编语言程序可直接译成CPU指令，命令处理器完成相应的运算。所以，要有效地编写汇编语言程序，就需要对微型计算机的结构和汇编语言都很熟悉。 徐存善主编 Assembly language operation codes are ea

48、sily remembered (MOV for moveinstructions, ADD for addition, and so on). You can also symbolically expressaddresses and values referenced in the operand field of instructions. Since you assign these names, you can make them as meaningful as themnemonics for the instructions. For example, if your pro

49、gram must manipulatea date as data, you can assign it the symbolic name DATE. If your programcontains a set of instructions used as a timing loop (a set of instructions executedrepeatedly until a specific amount of time has passed), you can name theinstruction group TIMERLOOP. 汇编语言操作代码很容易记（MOV就是移动指令

50、，ADD就是加法指令等等。还可以用符号表示（存储器）地址和指令的操作字段值。 因为指定了这些名字，指令就有了意义，比较容易记忆。比如，如果你在程序中要多次用到一个日期作为数据，你可以给这个日期指定一个符号化的名字DATE（日期）。如果你程序中含有用作延时循环的一组指令 (在指定的时间内反复执行的一组指令)，你可以给这段指令起名TIMERLOOP。 徐存善主编An assembly program has three constituent parts:(1) Machine instructions.(2) Assembler directives.(3) Assembler controls

51、.A machine instruction is a machine code that can be executed by the machine. Detailed discussion of the machine instructions can be found in the hardware manuals of the 8051 family or other microcontrollers.Assembler directives are used to define the program structure and symbols, and generate non-

52、executable code (data, messages, etc.).Assembler controls set the assembly modes and direct the assembly flow. 汇编程序有3个组成要素：（1）机器指令。（2）汇编指令。（3）汇编控制。 机器指令就是可以由CPU执行的机器代码。对机器指令的详细讨论可以参看8051系列或其他单片机的硬件手册。 汇编指令用于定义程序的结构和符号，生成非执行代码（数据、信息等）。 汇编控制设置汇编程序的模式和流向。 徐存善主编assembler sembl n. 汇编程序；汇编机；装配工simplify si

53、mplifai vt. 简化；使单纯；使简易symbolic simblik adj. 象征的；符号的executable eksikju:tbl adj. 可执行的；可实行的instruct instrkt vt. 指导；通知；命令；教授architecture :kitekt n. 建筑学；建筑风格；计算机构造，架构assembly sembli n. 装配；集会；汇编，编译symbolically simblikli adv. 象征性地；用符号表示operand prnd n. 操作数；运算对象mnemonics ni:mniks n. 记忆术manipulate mnipjuleit

54、vt. 操纵；操作；巧妙地处理New words and phrasesExercises 徐存善主编 I. Answer the following questions.1. What is an assembler?2. What areas of knowledge should a person understand in order to effectively write assembly programs? An assembler is a software tool designed to simplify the task of writing computer progr

55、ams.To effectively write assembly programs, a person should understand both the microcomputer architecture and the assembly language.Exercises 徐存善主编 I. Answer the following questions.3. What are the three constituent parts of an assembly program?4. Where can we find detailed discussion of the machine instructions?An