1、Good is good, but better carries it.精益求精，善益求善。Part3 UNIT5 A A First Look at Embedded SystemsPart3 UNIT5 A A First Look at Embedded SystemsUNIT 5 A A First Look at Embedded Systems 初識嵌入式系統 IntroductionThese are the days when the term like embedded is increasingly becoming more and more popular in the

2、 world. We are flooded with embedded systems that seem to be everywhere . Now the question is what basically embedded systems are. We can define an embedded system as “A microprocessor based system that does not look like a computer”. Or we can say that it is “A combination of computer hardware and

3、software, and perhaps additional mechanical or other parts, designed to perform a dedicated function. In some cases, embedded systems are part of a larger system or product, as is the case of an antilock braking system in a car”.嵌入式這個術語在世界上變得越來越流行已經有些日子了。我們在每個地方似乎都被嵌入式系統包圍。現在的問題是基本的嵌入式系統究竟是什么。我們可以把嵌

4、入式系統定義成“基于看起來不像計算機的系統的微處理器”。或者我們可以說它是“一個計算機硬件和軟件、還可能加上機械或其他設計用來執行指定功能部分的組合。在一些情況下，嵌入式系統是一個更大系統或產品的一部分，就像轎車中防抱死剎車系統一樣”。Embedded systems include a variety of hardware and software components, which perform specific functions in host systems, for example, satellites, washing machines, robots, hand-held

5、 telephones and automobiles.嵌入式系統包括不同的硬件和軟件部分，在主系統中執行特定的功能，例如，在衛星、洗衣機、機器人、手持電話和汽車中。Modem, hard drive, floppy drive, and sound cardeach of which is an embedded system. Each of these devices contains a processor and is designed to perform a specific function. For example, the modem is designed to send

6、 and receive digital data over an analog telephone line. Thats it. And all of the other devices can be summarized in a single sentence as well. If an embedded system is designed well, the existence of the processor and software could be completely unnoticed by a user of the device. Such is the case

7、for a microwave oven, VCR, or alarm clock. In some cases, it would even be possible to build an equivalent device that does not contain the processor and software.調制解調器、硬盤驅動器、軟盤驅動器和聲卡每一個都是嵌入式系統。這些設備每一個都包含一個處理器設計用來執行一個特定的功能。例如，調制解調器設計用來通過一根模擬信號電話線發送和接收數字數據。其他所有的設備也都能用一個簡單的句子概括。如果一個嵌入式系統設計精良，設備用戶可以完全忽

8、略處理器和軟件的存在。就像對于一個微波爐、VCR或鬧鐘的情況。在一些情況下，甚至可以制造一個不包含處理器和軟件的同等設備。 Attributes of an Embedded System嵌入式系統的屬性As embedded systems started progressing, they started becoming more and more complex. Additionally, new attributes that got added to these systems were smart and intelligent. Not only were the embed

9、ded devices able to do their jobs but also were able to do them smartly. These attributes can be difined as:隨著嵌入式系統開始發展，它們變得越來越復雜。另外，加入到這些系統的新屬性是聰明和智能的。嵌入式設備不僅能完成它們的工作而且能聰明地完成。它們的屬性可以被定義為：Computational Power These devices have some amount of computing power. A very simple 8-bit controller or a high-

10、end 64-bit microprocessor could provide this computation power.計算功能 這些設備有一定的計算功能。一個非常簡單的8位控制器或一個高端64位微處理器能提供這種計算功能。Memory The next requirement is memory. These devices possess some amount of memory that can be used by the processor and also some to remember user data and preferences.存儲器 接下來的要求是存儲器。這

11、些設備擁有一些存儲容量，能被處理器使用，也有一些用來記憶用戶數據和參數。Realtime All the devices have to respond to user/environmental inputs within a specified period of time.實時性 所有的設備在一個特定時間期限內必須對用戶或環境輸入作出反應。Communication The device must be able to receive inputs given by other devices in the environment, process it and provide some

12、 solid output to the other devices or users.通訊能力 設備必須能接收周圍環境中其他設備給定的輸入，并進行處理和提供一些可靠輸出給其他設備或用戶。Dynamic decisions The system should be albe to change its next course of activity based on the change of input from its sensors or surroundings.動態決定 系統能基于傳感器輸入或周圍環境輸入的變化改變它接下來的行動過程。Applications of Embedded

13、Systems嵌入式系統的應用Embedded systems are the applications that fuel some of the microprocessors that play a hidden but crucial role in our everyday lives. These are the tiny, quick, and smart microprocessors that live inside printers, answering machines, elevators, cars, cash machines, refrigerators, the

14、rmostats, wristwatches, and even toasters. Embedded systems are on the cutting edge of consumer electronics, poised to revolutinize various technologies by making them “smarter.”在我們的日常生活中，嵌入式系統是一些微處理器的動力，發揮著隱蔽卻很重要的應用。它們是小巧、迅捷、智能的微處理器，存在于打印機、電話答錄機、電梯、汽車、點鈔機、電冰箱、自動調溫器、腕表甚至烤箱中。嵌入式系統是消費電子中最前沿的技術，它們的“智能化

15、”將徹底改變各種技術。Embedded System Applications describes the latest techniques for embedded system design in a variety of applications. This also includes some of the latest software tools for embedded system design. Some of the examples of embedded systems are as follows:嵌入式系統應用描述了嵌入式系統設計在不同應用中的最新技術。這也包括了

16、一些嵌入式系統設計的最新軟件工具。嵌入式系統的一些實例如下：1) Automatic teller machines; 自動柜員機2) Computer printers; 計算機用打印機3) Disk drives; 磁盤驅動器4) Cellular telephones and telephone switches;移動電話和電話交換機5) Inertial guidance systems for aircraft and missiles;飛行器和導彈慣性導航系統6) Medical equipments; 醫學設備7) Video game consoles; 電子游戲機控制臺8)

17、Industrial machinery use programmable logic controllers to handle automation and monitoring;工業機械用可編程邏輯控制器去處理自動化和監測；9) Engine control computers and antilock brake controllers for automobiles;汽車用發動機控制計算機和防抱死控制器；10) Wristwatches; 手表11) Household appliances, including microwave ovens, air conditioners,

18、iron, washing machines, and television sets;家用電器，包括微波爐、空調、熨斗、洗衣機和電視機；12) Home automation products, like thermostats, sprinkler, and security monitoring systems;家用自動化產品，如自動調溫器、噴灑器和安全監視系統；13) Network equipment, including trouters and firewalls;網絡設備，包括路由器和防火墻；14) Traffic control (e.g. intelligent traff

19、ic lights);交通控制（比如智能交通燈）；15) Music Systems; 音樂系統；16) Card Reader. 讀卡器。 Benefits of Embedded Systems 嵌入式系統的好處Taking reference of the above examples, we can well imagine how much such kinds of systems have served humanity. Whether these benefits are in concerned with security purposes or with humans c

20、omforts, in fact these intelligent systems helped humanity in every phase of life. They have helped man in their progress by developing the new technologies. Embedded microprocessors enable firms to compete on product and service innovation, by adding product and service features that customers valu

21、e, but which would be largely impossible without this technology. According to market researchers, consumers love electronic equipment that can do “smart” things like transmit instructions to other devices wirelessly via infrared signals; be programmed to operate automatically; and connect to super-

22、technologies, such as satellites, to bring remote power into their own hands. Such systems have made their life easy and comfortable.以上面的例子為參考，我們能很容易想象有多少此類的系統在為人類服務。不管這些好處是涉及到安全目的還是人類的舒適性，實際上在生活的每一方面這些智能系統都在幫助人們。它們幫助人們開發新技術。嵌入式微處理器使得公司在產品和服務創新上競爭，通過增加產品和服務特點為用戶創造價值，如果沒有這種技術，用戶價值是不可能實現的。根據市場研究人員的分析，

23、消費者喜歡做事“機靈”的電子設備，比如通過紅外信號向其他設備發送指令；通過編程自動運行；能與諸如衛星等超級技術連接，把遠處的能量帶到身邊。這樣的系統使得生活安逸舒適。Future Prospects展望未來It is unavoidable that computer will continue to become cheaper, smaller and more powerful, and that eventually they will be inexpensive enough to put in nearly every product. In addition, nearly a

24、ll computers equipped products will have some kind of access to either local networks, or the Internet.計算機將繼續變得更加便宜，外形更小巧，功能更強大，這在將來是不可避免的，它們最終將更加廉價，幾乎在每件產品中都能看到它們的身影。此外，幾乎所有配備電腦的產品都能訪問局域網或互聯網。Over the next decade, many common household items will be given embedded systems, reinventing them, and cha

25、nging them for forever. Like desktop publishing, and later the Internet, embedded systems is a technology that will fundamentally, and permanently, change the way advertising and marketing works. It will also permanently change the kind of products that are made, and how they are made. The development of intelligent products, and intelligent product marketing, made possible by embedded systems, where these machines exist fo