嵌入式系统概论英文.ppt
嵌入式系统PPT优秀课件
设备驱动层是嵌入式系统中必不可少的重要部分；使 用任何外部设备都需要有相应的驱动程序的支持，它 为上层软件提供了设备的操作接口。上层软件不用理 会设备的具体内部操作，只须调用驱动层程序提供的 接口即可。驱动层一般包括：
硬件抽象层(HAL)
板级支持包(BSP)
相关统计表明，2012 年我国电子制造规模达 5.45 万 亿元，位居世界第二；电视、程控交换机、笔记本电 脑、显示器和智能手机等主要电子信息产品的产量居 全球首位。
我国嵌入式系统的应用主要分布在电信、医疗、汽车、 安全和消费类等行业。来自 2010-2011 年度的行业调 查数据显示，目前嵌入式产品应用最多的三大领域：
硬件层，是整个嵌入式系统的根本，如果现在单片机 及接口这块很熟悉，并且能用C和汇编语言来编程的 话，从嵌入式系统的硬件层走起来相对容易，硬件层
也是驱动层的基础，一个优秀的驱动工程师是要能够 看懂硬件的电路图和自行完成CPLD的逻辑设计的， 同时还要对操作系统内核及其调度性相当的熟悉的。
嵌入式系统的软件体系是面向嵌入式系统特定的硬件体系和用 户要求而设计的，是嵌入式系统的重要组成部分，是实现嵌入 式系统功能的关键。嵌入式系统软件系统和通用计算机软件体 系类似，分成驱动层、操作系统层、中间件层和应用软件层等
中间件是用于帮助和支持应用软件开发的软件，通常 包括数据库、网络协议、图形支持及相应开发工具等。 例如，MySQL、TCP/IP、GUI等都属于这一类软件。
MySQL[1] 是一个关系型数据库管理系统， 是一个数 据库
TPC/IP 是通信协议 GUI： （Graphical User Interface）图形用户界面
三大领域所占比例之和接近60%
(完整)嵌入式系统精品PPT资料精品PPT资料
应用范例介绍二
iPhone® Went on sale in June 2007
One Samsung ARM1176
application processor core Memory capacity: 8 – 16 GB Display: 3.5 inch widescreen multi-
And the list goes 全on a自nd 动on 操作循环
Televisions
24 MB of int嵌erna入l m式ain m系em统ory为一种计算机软件与硬件的综合体，特别强调「量身定做」 LDEisGkOdrTivEeCs H的NIC原El则eme，nts基于某一种特殊用途上，针对这项用途开发出截然不同的系 Anti-lock bra统kes，是所谓的客制化(Customized)系统。
32-bit ARM7 microprocessor 256 Kbytes FLASH, 64 Kbytes RAM
Bluetooth wireless communication using NXT software only.
USB 2.0 port 4 input ports, 6 wire digital platform 3 output ports, 6 wire digital platform 100 x 64 pixel LCD graphical display Sound channel with 8-bit resolution Stores multiple programs
Take advantage of application characteristics to optimize the design: Do not need all the general-purpose bells and whistles
第1章嵌入式系统概论
第1章 嵌入式系统概论
如何选择操作系统：
商用的如VxWorks，emBos等价格高，采用不易。 WinCE操作系统 由于WinCE开发都是大家熟悉的VC++环境，所以学过 Windows程序设计课程不会有多大难度，这也是WinCE容易 被人们接受的原因，开发环境方便快速，微软的强大技术支 持。 目前，嵌入式ARM+linux是一个发展很热的方向。
第1章 嵌入式系统概论
1.5嵌入式系统的开发模式
宿主机
目标机 串口线
网线
第1章 嵌入式系统概论
• 嵌入式系统的软件使用交叉开发平台进行开发。 – 系统软件和应用软件在主机开发平台上开发 – 系统软件和应用软件在嵌入式硬件平台上运 行。 • 宿主机（Host）是用来开发嵌入式软件的系统。 • 目标机（Target）是被开发的目的嵌入式系统。 • 交叉编译器（Cross-compiler）是进行交叉平台 开发的主要软件工具。它是运行在一种处理器体 系结构上，但是可以生成在另一种不同的处理器 体系结构上运行的目标代码的编译器。
第1章 嵌入式系统概论
1.6嵌入式系统的测试
• 测试目的:
– – – – 找到软硬件设计中的错误 减少风险 节约成本 提高性能
测试什么: • 功能调试(黑盒测试)
– 压力测试,边界测试,异常测试 – 错误测试,随机测试,性能测试������
• 覆盖测试(白盒测试)
– 语句测试,判定和分支测试,条件覆盖
第1章 嵌入式系统概论
第1章 嵌入式系统概论
第1章 嵌入式系统概论
第1章 嵌入式系统概论
(3) 支持32位ARM指令集和16位Thumb指令集。
(4) 支持32位的高速AMBA总线接口。
嵌入式系统--课件
7
外围设备
第1章 嵌入式系统基础
外围设备是指在一个嵌入式系统中，除了嵌入式处理器以外 的完成存储、通信、调试、显示等辅助功能的其他部件。
根据外围设备的功能可分为以下3类：
存储器：静态易失型存储器(RAM，SRAM)、动态存储器 (DRAM)和非易失型存储器(Flash)。其中，Flash以可擦写 次数多、存储速度快、容量大及价格低等优点在嵌入式领域 得到了广泛的应用。
嵌入式操作系统常常有实时要求，所以嵌入 式操作系统往往又是“实时操作系统”。
9
应用软件
第1章 嵌入式系统基础
嵌入式系统的应用软件是针对特定的实际专业领域的，基于相 应的嵌入式硬件平台，并能完成用户预期任务的计算机软件。
嵌入式软件的特点如下： (1)软件要求固态化存储。 (2)软件代码要求高质量、高可靠性。 (3)系统软件的高实时性是基本要求。 (4)多任务实时操作系统成为嵌入式应用软件的必需。
目前主要的嵌入式处理器类型有ARM 、MIPS、 Am186/88、386EX、PowerPC、68000系列等。
18
微控制器
第1章 嵌入式系统基础
又称单片机，这种８位的电子器件目前在嵌入式设 备中仍然有着极其广泛的应用。
单片机芯片内部集成Flash、RAM、总线逻辑、定 时器/计数器、WatchDog、I/O，串行口、脉宽 调制输出、A/D，D/A等各种必要的功能模块和外 围部件。
10
第1章 嵌入式系统基础
1.1.3 嵌入式系统的特点
软硬件一体化，集计算机技术、微电子技术、行 业技术为一体； 需要操作系统支持，代码小、执行速度快； 专用紧凑，用途固定，成本敏感； 可靠性要求高； 多样性，应用广泛、种类繁多。
嵌入式系统(英文版)
Embedded systems with limited power resourcesThis paper deals with the design approach for embedded systems with limited power re-sources. The focus is on embedded systems powered purely by energy harvested from the surroundings. Realtime operation and power consumption are critical design aspects of these systems. A number of design problems are discussed and solutions are presented. Selected products are looked at as examples of successful implementation of the solutions.Attila Strba, Research & Development, EnOcean GmbH1. INTRODUCTIONSignificant advances in microelectronics technology made the increasing miniaturization of embedded systems possible. This trend to miniaturization began in the late 1960s and, as stated by Moore’s Law [3] that the power of microprocessors doubles about every 18 months, has held true with astonishing accuracy and consistency until the beginning of the 21st century. An announcement like that by IBM concerning the use of 29.9 nm technology to print circuits [7] indicates that this trend will continue for a number of chip generations.The trend is leading to and will result in the development of tiny embedded systems, integrated into more and more everyday objects. And will create a world of smart devices surrounding us. For exam-ple, parents will no longer lose track of their children, even in the busiest crowds, when location sen-sors and communication modules are sewn into their clothes. Similar devices attached to timetables and signposts could guide blind or foreign people in unknown environments by talking to them [6]. Another interesting possibility offered by such technology would be the creation of intelligent homes where a refrigerator can detect old food, a washing machine can query the instructions for dirty clothes, or window and door handles indicate whether they are open or closed. This concept called ambient intelligence, where humans have computing and networking technology embedded in their surroundings, was developed by the ISTAG advisory group [4], [5], [6].While this vision may sound utopian when you first hear about it, current technology is already at a stage where it is possible to realize it. Ambient intelligence requires that there be thousands of tiny embedded devices in the environment. Each of these devices require some source of power for it to function. While power can be sent to them through cables or batteries, neither of these possibilities offers an effective and longterm solution. The large number of these devices makes it highly desirable that they be fully self-sustaining and service-free. This can be achieved by harvesting energy from the environment.Energy harvesting is a way of using the omnipresent sources of energy in our surroundings, like from moving objects, vibrating machine parts, temperature changes, electromagnetic waves such as light, radio or infrared [8], [9]. The idea is not new, but successful and low-cost realization in embedded systems calls for the right expertise. A specific design approach is needed for embedded systems fulfilling the concept of ambient intelligence.EMBEDDED SYSTEMS WITH LIMITED POWER RESOURCES2. EMBEDDED SYSTEM DESIGN WITH LIMITED POWER RESOURCESEach system design has to begin with a specification. Focusing on devices for an ambient intelligence application, we will look at the design problems of embedded systems expected to satisfy the following requirements:self-sustaining and service-freeenergy harvesting from the environmentseamless wireless communication interfaceinteraction with realtime eventsunobtrusive hardwareThe first step to take when designing an embedded system is to build its architecture. An architecture model of an embedded system with limited power resources is shown in Figure 1. To understand the design problems of such systems, you must first understand their functional concept.The energy harvested from the environment – which can be a single pulse or a continuous flow from a solar cell, thermoelectric or electrodynamic energy converter – is temporarily stored and then used to power a microcontroller for a short period of about several milliseconds. During this time the con-troller receives data from associated sensors and transmits the data wirelessly together with an iden-tification code. After transmission the circuit turns off completely and can be started again when en-ergy is available. Or if there is a continuous flow of energy (for example from a solar cell or thermo energy converter) the circuit enters a sleep mode with low energy consumption [8].There are three critical design constraints with such systems:energy managementcomputing resourcesprice aspectAll these parameters are tied together and for a successful design they must be properly balanced. Changing one of them could influence another. They are looked at below and possible solutions are pointed out.Figure 1 Architecture model of embedded system with limited power resourcesEMBEDDED SYSTEMS WITH LIMITED POWER RESOURCES2.1Energy managementOnce the requirements and architecture of the power limited system are defined, the next important part of the design process is to determine how much energy is available. This can be done through an energy budget analysis that determines energy availability and consumption during the period of time. It is essential to validate energy budget calculations with simulations, although building up a simulation model of the system is not a trivial task. There are several software tools available on the market that can help here, for example Matlab Simulink or P-Spice. All following system design steps must be based on the energy budget calculations.Energy converters deliver a certain amount of energy in the form of voltage and current that is stored in capacitors. From the time delivery aspect you can characterize energy converters as follows: converters delivering energy periodicallyconverters delivering short energy burstsThe first group of converters can power a system seamlessly and continuously by storing the energy when available for a longer time. In such a scenario the time for completing the tasks does not play a critical role. Examples of converters belonging to this group are solar panels, thermo converter based on a Peltier element, windmills and dynamos. The concept of efficient energy management in such systems is to switch on the circuit for as short a time and as infrequently as the application allows, and for the rest of the time the circuit should idle with very low power consumption.With the second group of energy converters the time aspect is critical. An example of such a con-verter is a piezo or an electrodynamical element. The greatest energy savings in such systems can be achieved by starting a system and completing the required processing tasks within the shortest pos-sible time.An important requirement for a successful design is to minimize the power consumption factors. Based on the embedded system architecture shown in Figure 1, the following are domains where you can apply power saving strategies. It is important to understand that most of the optimization factors spoken of here can interact, and wrong combination can cancel the energy saving benefit.2.1.1 Microcontroller power saving strategiesSupply voltageIn the case of a microcontroller, power consumption is proportional to the square of the supply volt-age. So the lower the supply voltage of the microcontroller, the better are the power perspectives [10]. There are three types of power consumption relevant to microcontrollers and digital circuits: Internal power, switching power and leakage. Internal power and switching power are referred to as dynamic power and leakage as static power [18]. When choosing the microcontroller for a system it is important to consider these values.Startup timeThe startup time of a microcontroller also plays also a very important role. It is usually influenced by oscillator delay. Mechanical resonant devices such as crystals and ceramic resonators can take several milliseconds to stabilize. RC oscillators, by contrast, provide fast startup but generally suffer from poor accuracy over temperature and supply voltage [19]. To save time it is advisable to use a micro-controller that can start with an RC oscillator and subsequently switch to a crystal oscillator.EMBEDDED SYSTEMS WITH LIMITED POWER RESOURCESPower featuresMicrocontrollers offer several power saving features like adjustable clock frequency, voltage scaling, different sleep modes. Many embedded processors now include features such as run-time power modes that are used to scale power consumption:Static power management: this approach does not depend on CPU activity. An example of this style is user-activated power-down modes.Dynamic power management: this approach is based on CPU activity. An example of this ap-proach is disabling functional units.It is important to consider how much energy saving can be achieved by which features in the de-signed system.Software power saving strategiesOne of the ways to reduce system power consumption by software is with energy-efficient source code transformation. There are several high-level software optimization techniques of performance such as loop unrolling, procedure in-lining [20]. Better software performance reduces execution time, therefore energy is saved.Another way of saving energy is to use operating systems that support energy-constrained RT sched-uling [10] or dynamic power management (DPM) [21]. DPM strategies are strategies that attempt to make power-mode-related decisions based on information available at runtime.Besides sophisticated software methods, much energy can be saved by sticking to few simple rules: More CPU activity means more power.The software should put the microcontroller to sleep when waiting for an event.One thing to consider when waking a CPU is the oscillator startup time.There are also power down costs. Power down costs include factors such as the time to enter and exit the mode and the energy consumed by doing this.Avoiding flash, EEPROM and other memory writes.Simplicity of software means efficiency, resulting in energy saving.2.1.2 RF transmission power saving strategiesMost energy in an embedded system defined by the architecture shown in Figure 1 is consumed by radio communication. It is caused by the power consumption of each RF block like LNA, down-converter, synthesizer, etc. This leads to the conclusion that power limited embedded systems should use RF transmitters with a minimal number of active components. Another important fact of minimiz-ing power drained by the RF block is to minimize the time the transmitter is turned on [22].Saving energy during RF transmission is also possible by using an energy optimized transmission protocol with small data overhead and strategies such as not transmitting empty data (e.g. leading zeros). An important consideration during energy optimized RF design is the transmission rate and modulation type.2.2 Computing resourcesEmbedded systems with limited power resources have limited functionality time given by the circum-stance that all tasks must be executed during the time period while energy is available. Therefore the correctness of the computations depends not only on the logical correctness of a computation but alsoEMBEDDED SYSTEMS WITH LIMITED POWER RESOURCESon the time in which the result is produced. Based on this fact all embedded systems with limited power resources are considered to be realtime.To ensure that all required tasks are completed in time, there must be enough computing resources available. This requirement could be fulfilled by using a powerful microcontroller. On the other hand the more powerful and complex the microcontroller, the more energy is required for its functionality. What makes the design of the system even more difficult is that the time period during which enough operational energy is available varies. This is caused by the fact that the amount of energy delivered by the energy converter is not constant. It is important to calculate with the worst case time period when the least energy is available in the system.To determine what computing resources are needed for correct functionality of the system, it must be classified from the perspective of the application. According to the timeline aspect you can classify realtime embedded systems in the following way [23], [24]:Hard: a late response is incorrect and implies a system failure. An example of such a system is medical equipment monitoring vital functions of a human body, where a late response would be considered a failure.Soft: timelines requirements are defined by using an average response time. If a single com-putation is late, it is not usually significant, although repeated late computation can result in system failures.Weakly hard: this is a combination of both hard and soft timelines requirements. A weakly hard system is one in which few late responses will not lead to a total failure, but missing more than a few may lead to complete and catastrophic failure. For example, if a smoke de-tector after detecting smoke starts the alarm few seconds later or earlier it is not functionally critical. But delaying the alarm by several minutes can lead to serious damage.The second classification criteria is to determine whether the system is fail-safe or fail-operational. For example, if a temperature sensor powered by a thermo converter skips several measurement data caused by lack of energy, it is not critical. In the case of the smoke detector powered by a solar cell, such a situation is not allowed to happen.Another important design step is to list and analyze each task that the system must perform during its function. The typical tasks of the system based on the architecture shown in Figure 1 are: self-test (memory, program check)power management (sleep mode/wake-up timing, available energy measurements)data processing (data acquisition from sensors and evaluation, radio protocol preparation, CRC calculation, encryption)data transmission (transmission timing, listen before talk, repetitive transmission, frequency hopping to assure failure safe transmission)2.3 Price aspectThe total cost of ownership for embedded systems powered by ambient energy must compete with battery powered solutions or even with wired solutions. Ambient energy powered systems become economically feasible if the cost of the devices together with energy converters will be comparable to battery costs – for similar performance of the whole system. In this case service-free systems will ensure wide acceptance [8].EMBEDDED SYSTEMS WITH LIMITED POWER RESOURCESTable 1 Energy converters overview from the price and delivered energy aspectThe price of the energy converters is not the limiting factor. Currently electrodynamic converters and solar cells are already products in mass production, for an acceptable price. For an overview of the amount of energy a list of energy converters and their amount of delivered energy is shown in Table 1. The only possible way to achieve low-cost embedded systems is to reduce the number of compo-nents the system is composed of and to set the aim to a high level of integration [22].Light energy Piezoelectric ele-mentElectrodynamic ele-mentThermocouplesPhotovoltaic solar cell 20x6x1 mm 33x22x10 mm5x5x2 mm10x20x2 mme.g. button push 3mm x 5 Ne.g. button push 2 mm x 5 NTemp. differenceof 5 KLight 400 lux200 µWs per opera-tion – efficiency 1%230 µWs per operation – efficiency 60%20 µW permanently20 µW perma-nentlyEMBEDDED SYSTEMS WITH LIMITED POWER RESOURCES3. APPLICATION EXAMPLEOver the past decades several experiments tried to make the vision of ambient intelligence an every-day reality. Several projects and prototypes were realized but there is still a lack of such embedded systems on the market. Today, thanks to a few breakthrough companies, ambient intelligence is gradually becoming a reality. What follows is a successful implementation of an embedded system with limited power resources that is already available on the market.Figure 2 Electrodynamically powered radio transmitter device; the top picture shows the module con-struction, and in the bottom pictures two applications implemented with this module are illustratedThe product shown in Figure 2 is a transmitter device called PTM 200 from the company EnOcean that enables the implementation of wireless remote controls without batteries. Power is provided by a built-in electrodynamic energy converter. When the energy bow is pushed down, electrical energy is created that powers up a microcontroller and the RF transmitter. The microcontroller reads the status of the contact nipples and after that a radio telegram is transmitted to the air at 868 MHz in Europe or at 315 MHz in North America. The transmission range is approximately 300 meters in a free field. Key applications of this device are wall-mounted flat rocker switches as well as handheld remote con-trols [25].4. CONCLUSIONThere are a large number of design requirements with power limited embedded systems, making the design process a complicated procedure. The most efficient way to handle all the design problems is to develop an integrated system on chip solution in the form of an ASIC. At present there is an ongo-ing ASIC development that should offer an effective cost optimized solution to most of the design problems mentioned in this paper.EMBEDDED SYSTEMS WITH LIMITED POWER RESOURCESReferences[1] Sam Siewert: Real-Time Embedded Components and Systems[2] Last access 3.2.2007/[3] The Origin, Nature and Implications of “Moore’s Law”Last access 18.2.2007/~gray/Moore_Law.html[4] Ubiquitous Computing: An Interesting New ParadigmLast access 18.2.2007/classes/cs6751_97_fall/projects/say-cheese/marcia/mfinal.htmlIntelligence[5] AmbientLast access 18.2.2007/definition[6] J. Bohn, V. Coroama, M. Langheinrich, F.Mattern, M. Rohs: Social, Economic and Ethical Im-plications of Ambient Intelligence and Ubiquitous Computing, published in:W. Weber, J.M. Rabaey, E. Aarts: Ambient Intelligence, Netherlands: Springer, 2005čip vyrobený 29,9nm technologiía[7] IBMLast access 3.2.2007http://www.svethardware.cz/art_doc-46D82534D2E94655C125711C0045AF52.html[8] F. Schmidt, M. Heiden: Wireless Sensors Enabled by Smart Energy – Concepts and Solutions[9] Energy-harvesting chips: The quest for everlasting lifeLast access 18.2.2007/ART_8800378146_765245_1fe14900_no.HTM[10] Energy-Constrained Scheduling for Weakly-Hard Real-Time Systems[11] Thomas A. Henzinger, Joseph Sifakis: The Embedded Systems Design Challange[12] Language Design: LustreLast access 18.2.2007, http://www-verimag.imag.fr/~synchron/index.php?page=lang-design[13] EstrelLast access 18.2.2007,http://www-sop.inria.fr//[14] SystemCLast access 4.2.2007/EMBEDDED SYSTEMS WITH LIMITED POWER RESOURCES[15] AADLLast access 4.2.2007/[16] Daniel Gajski, Frank Vahid, Sanjiv Narayan, and Jie Gong: Specification and Design of Em-bedded Systems, Prentice Hall, 1994[17] F. Schmidt, Wolfgang Heller: Radio sensors powered by ambient energy: from strange ideas to mass market products[18] Ronald J. Landry: Low-power microcontroller design techniques for mixed-signal applications Last access 24.2.2007/articles/article9822.html[19] Microcontroller Clock - Crystal, Resonator, RC Oscillator or Silicon Oscillator?[20] Eui-Young Chung, Luca Benini, Giovanni De Micheli: Energy Efficient Source Code Transforma-tion Based on Value Profiling[21] S. Irani, S. Shukla and R. Gupta: Online Strategies for Dynamic Power Management in Sys-tems with Multiple Power Saving States[22] J. Ammer, F. Burghardt, E. Lin, B. Otis, R. Shah, M. Sheets, J.M. Rabaey: Ultra-Low Power Integrated Wireless Nodes for Sensor and Actuator Networkspublished in: W. Weber, J.M. Rabaey, E. Aarts: Ambient Intelligence, Netherlands: Springer, 2005 [23] Real time and embedded systemsLast access 3.2.2007/company/realtime_perspective/embedded_systems.aspx[24] Dave Stewart: Introduction to real timeLast access 3.2.2007/showArticle.jhtml?articleID=9900353[25] User manual: Pushbutton Transmitter Device PTM200Last access 25.2.2007/php/upload/pdf/MAN_ENG2.pdf。
1嵌入式系统概述.ppt
系统同时运行多个实时性任务，系统必须同时控制这些动作，这些动 作有些速度慢，有些速度快。
环境相关性
嵌入式系统不是独立的，而是与其被嵌入的设备紧密相关联。
25
嵌入式系统特点
系统内核小
由于嵌入式系统一般是应用于小型电子装置的，系统资源相对有限，所以 内核较之传统的操作系统要小得多。
如：FreeRTOS，内核只有几K，而Windows的内核则要大得多。
专用性强
嵌入式系统的个性化很强，其中的软件系统和硬件的结合非常紧密，一般 要针对硬件进行系统的移植。
针对不同的任务，往往需要对系统进行较大更改，程序的编译下载要和系 统相结合，这种修改和通用软件的“升级”是完全不同的概念。
不可垄断性
PC有WinTel垄断。 嵌入式系统工业的基础是以应用为中心的芯片设计和面向应用的软件产品
以往计算机分类：
大型计算机、中型机、小型机和微计算机
目前计算机分类：
超级计算机，大型计算机、工作站、微计算机、 亚微计算机
亚微计算机(嵌入式计算机) 是以嵌入式系统 的形式隐藏在各种装置、产品和系统中。
17
嵌入式系统定义
一般定义
以应用为中心、以计算机技术为基础，软硬件可裁剪, 应用系统对功能、可靠性、成本、体积、功耗和应用 环境有特殊要求的专用计算机系统。是将应用程序、 操作系统和计算机硬件集成在一起的系统（技术角度）
狭义上讲，我们更加强调那些使用嵌入式微处理器构成独 立系统，具有自己操作系统，具有特定功能，用于特定场 合的嵌入式系统。本课程中的嵌入式系统是指狭义上的嵌 入式系统。
22
嵌入式系统硬件源起
发展历史
嵌入式系统本身是一个相对模糊的定义。一个手持的 MP3和一个PC104的微型工业控制计算机都可以认为是嵌 入式系统。
嵌入式系统简介0.ppt
动程式设计、应用软件设计、嵌入式系統应用设计。 • 在很多方面，嵌入式系统软件开发与一般电脑系統有著
很多不同之处，尤其从事嵌入式系统软件开发者，需要 对硬件有一定程度了解，才能对嵌入式系统进行开发。 (入门门槛较高) • 目前的嵌入式系统软硬件设计人才十分缺乏，故熟悉嵌 入式系统(软硬件设计)将有助于未來的发展。
• 嵌入式系統为一种软件与硬件的综合体，特別强调“量 身定做”的原則，基于某一种特殊用途上，针对這項用 途开发出截然不同的一項系統出來，這就是所谓的客制 化(Customized)系統。
1-4 / 44
何谓嵌入式系統 ?
• 嵌入式系統具备了下列四個特性 :
。用來执行特定功能 。以微CPU与周边构成核心 。需要严格的時序与稳定度 。全自动循环操作
。 一部目标装置里头，可能會有数十個甚至数百、数千個嵌入式 系統，每個「系統」均负责执行一項专责的功能。
。 因此，「嵌入式作业系統」成為嵌入式系統不可或缺的要素。
• WinCE (Microsoft) • Embedded Linux
1-6 / 44
1 何谓嵌入式系統 ?
• 嵌入式系統是「功能导向」的系統 :
1-13 / 44
3 嵌入式系統的应用
• 嵌入式系統的应用領域
。 家用市場
• 机上盒、掌上電腦、DVD、MP3、数码相机、数码電視、WebTV、网 络冰箱、网络空調、家庭闸道、智慧家用電器、車上导航器系統 等
。 通信市場
• 電話交换系統、电缆系統、卫星和全球定位系統（L3D）、資料交 换设备、移动式電話等
第一顆4-bit微处理器Intel 4004
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
1.3 The characteristics of embedded system
2. Real time response Most real-time systems are embedded systems, system relies on the hardware and real-time operating system RTOS closely, can in the limited time to make rapid response to external events; Secondly, in the embedded application, most systems has a good real-time performance, and embedded systems mostly with fast start-up characteristics.
5
Hale Waihona Puke 1.2.1 Embedded system overview
Two important features of embedded system: 1. to the application as the center: embedded systems
should not be independent of the application. 2. is based on computer technology: computer system is
4
1.2.1 Embedded system overview
From the application point of view to define, embedded system is a combination of software and hardware, and performs a specific function.
Other
Medical care
Consumer electronics
Telecom
Signal communication
7
1.3 The characteristics of embedded system
1. Diversity Application of the embedded system is varied, have been widely applied to various fields of society. Embedded type of equipment has become increasingly diverse, there are a variety of processors and peripheral equipment support.
2
1.1 Introduction
Embedded system is widely used, it becomes the one of the fastest developing fields. The study of embedded system has a very important practical significance
9
1.3 The characteristics of embedded system
3. Robust and reliable At present, there are mainly two kinds of mechanisms to ensure the reliability of the system, one is the hardware mechanism, such as a hardware watchdog timer, it can be in the software of losing control of the system to normal operation; two is a software system, such as memory protection and reset mechanism. In order to improve the reliability of the system, embedded systems often use solid state storage, software is solidified in the memory chip, rather than stored in disk carrier in.
2. IEEE ( International Institute of electrical and Electronics Engineers ) for embedded system is defined by: embedded system is" used for control, monitor or assist the operation of equipment".
composed of software and hardware, the embedded system is no exception.
6
1.2.2 Application of embedded system in the mainstream
Embedded product market share are as follows:
Embedded system overview
1
Embedded system overview
1.1 Introduction 1.2 Embedded system overview 1.3 The characteristics of embedded system 1.4 Embedded systems architecture 1.5 Embedded development trend
This chapter introduces the definition of embedded system and system structure analysis of embedded system, status, prospects the development trend of the field.
3
1.2 Embedded system overview
Definition 1. The computer is embedded into a larger, more special
object, form" embedded computer system", referred to as " embedded system ".
From a technical point of definition, it is take the application as the center, take the computer technology as the foundation, the software and hardware can be cut.