Part3 UNIT5 A A First Look at Embedded Systems

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 初识嵌入式系统 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”.嵌入式这个术语在世界上变得越来越流行已经有些日子了。我们在每个地方似乎都被嵌入式系统包围。现在的问题是基本的嵌入式系统究竟是什么。我们可以把嵌

4、入式系统定义成“基于看起来不像计算机的系统的微处理器”。或者我们可以说它是“一个计算机硬件和软件、还可能加上机械或其他设计用来执行指定功能部分的组合。在一些情况下，嵌入式系统是一个更大系统或产品的一部分，就像轿车中防抱死刹车系统一样”。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.嵌入式系统包括不同的硬件和软件部分，在主系统中执行特定的功能，例如，在卫星、洗衣机、机器人、手持电话和汽车中。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.调制解调器、硬盘驱动器、软盘驱动器和声卡每一个都是嵌入式系统。这些设备每一个都包含一个处理器设计用来执行一个特定的功能。例如，调制解调器设计用来通过一根模拟信号电话线发送和接收数字数据。其他所有的设备也都能用一个简单的句子概括。如果一个嵌入式系统设计精良，设备用户可以完全忽

8、略处理器和软件的存在。就像对于一个微波炉、VCR或闹钟的情况。在一些情况下，甚至可以制造一个不包含处理器和软件的同等设备。 Attributes of an Embedded System嵌入式系统的属性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:随着嵌入式系统开始发展，它们变得越来越复杂。另外，加入到这些系统的新属性是聪明和智能的。嵌入式设备不仅能完成它们的工作而且能聪明地完成。它们的属性可以被定义为：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.计算功能 这些设备有一定的计算功能。一个非常简单的8位控制器或一个高端64位微处理器能提供这种计算功能。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.存储器 接下来的要求是存储器。这

11、些设备拥有一些存储容量，能被处理器使用，也有一些用来记忆用户数据和参数。Realtime All the devices have to respond to user/environmental inputs within a specified period of time.实时性 所有的设备在一个特定时间期限内必须对用户或环境输入作出反应。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.通讯能力 设备必须能接收周围环境中其他设备给定的输入，并进行处理和提供一些可靠输出给其他设备或用户。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.动态决定 系统能基于传感器输入或周围环境输入的变化改变它接下来的行动过程。Applications of Embedded

13、Systems嵌入式系统的应用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.”在我们的日常生活中，嵌入式系统是一些微处理器的动力，发挥着隐蔽却很重要的应用。它们是小巧、迅捷、智能的微处理器，存在于打印机、电话答录机、电梯、汽车、点钞机、电冰箱、自动调温器、腕表甚至烤箱中。嵌入式系统是消费电子中最前沿的技术，它们的“智能化

15、”将彻底改变各种技术。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:嵌入式系统应用描述了嵌入式系统设计在不同应用中的最新技术。这也包括了

16、一些嵌入式系统设计的最新软件工具。嵌入式系统的一些实例如下：1) Automatic teller machines; 自动柜员机2) Computer printers; 计算机用打印机3) Disk drives; 磁盘驱动器4) Cellular telephones and telephone switches;移动电话和电话交换机5) Inertial guidance systems for aircraft and missiles;飞行器和导弹惯性导航系统6) Medical equipments; 医学设备7) Video game consoles; 电子游戏机控制台8)

17、Industrial machinery use programmable logic controllers to handle automation and monitoring;工业机械用可编程逻辑控制器去处理自动化和监测；9) Engine control computers and antilock brake controllers for automobiles;汽车用发动机控制计算机和防抱死控制器；10) Wristwatches; 手表11) Household appliances, including microwave ovens, air conditioners,

18、iron, washing machines, and television sets;家用电器，包括微波炉、空调、熨斗、洗衣机和电视机；12) Home automation products, like thermostats, sprinkler, and security monitoring systems;家用自动化产品，如自动调温器、喷洒器和安全监视系统；13) Network equipment, including trouters and firewalls;网络设备，包括路由器和防火墙；14) Traffic control (e.g. intelligent traff

19、ic lights);交通控制（比如智能交通灯）；15) Music Systems; 音乐系统；16) Card Reader. 读卡器。 Benefits of Embedded Systems 嵌入式系统的好处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.以上面的例子为参考，我们能很容易想象有多少此类的系统在为人类服务。不管这些好处是涉及到安全目的还是人类的舒适性，实际上在生活的每一方面这些智能系统都在帮助人们。它们帮助人们开发新技术。嵌入式微处理器使得公司在产品和服务创新上竞争，通过增加产品和服务特点为用户创造价值，如果没有这种技术，用户价值是不可能实现的。根据市场研究人员的分析，

23、消费者喜欢做事“机灵”的电子设备，比如通过红外信号向其他设备发送指令；通过编程自动运行；能与诸如卫星等超级技术连接，把远处的能量带到身边。这样的系统使得生活安逸舒适。Future Prospects展望未来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.计算机将继续变得更加便宜，外形更小巧，功能更强大，这在将来是不可避免的，它们最终将更加廉价，几乎在每件产品中都能看到它们的身影。此外，几乎所有配备电脑的产品都能访问局域网或互联网。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