【精品】嵌入式系统概述.ppt

嵌入式系统概述 宋健建 南京大学软件学院 2004/12/21 内容 什么是嵌入式系统 嵌入式系统的历史和发展 嵌入式系统的组成 嵌入式系统的特点 嵌入式系统软件开发 1. What are embedded systems? Definition: Embedded system: any device that includes a programmable computer but is not itself a general-purpose computer. Take advantage of application characteristics to optimize the design: don’t need all the general-purpose bells and whistles. A More Detailed Definition 国内一般定义 嵌入式系统是以应用为中心，以计算机技术为基础，并且软硬件可裁剪，适用于应用系统对功能、可靠性、成本、体积、功耗有严格要求的专用计算机系统。 一般由嵌入式微处理器、外围硬件设备、嵌入式操作系统以及用户应用程序等四个部分组成，用于实现对其他设备的控制、监视或管理等功能。 Embedding a computer Examples Personal digital assistant (PDA). Printer. Cell phone. Automobile: engine, brakes, dash, etc. Television. Household appliances. PC keyboard (scans keys). Reference Interpretation (1) An embedded system is any computer system or computing device that performs a dedicated function or is designed for use with a specific embedded software application. Embedded systems may use a ROM-based operating system or they may use a disk-based system, like a PC. But an embedded system is not usable as a commercially viable substitute for general purpose computers or devices. Reference Interpretation (2) A specialized computer system that is part of a larger system or machine. Typically, an embedded system is housed on a single microprocessor board with the programs stored in ROM. Virtually all appliances that have a digital interface -- watches, microwaves, VCRs, cars -- utilize embedded systems. Some embedded systems include an operating system, but many are so specialized that the entire logic can be implemented as a single program. Reference Interpretation(3) 中国微机学会的定义： 嵌入式系统是以嵌入式应用为目的的计算机系统，可以分为片级、板级、系统级。 芯片级嵌入－ 含程序或算法的处理器 模块级嵌入－ 系统中的某个核心模块板 系统级嵌入－ 主计算机系统 1.2 嵌入式系统历史和发展 1971年代单片微处理器问世，它标志着嵌入式系统的开端。 从4个方面了解嵌入式系统历史 硬件 软件 代表产品 系统结构 嵌入式硬件的历史 1971年Intel 4004, 4位微处理器 TI, TMS1000, 4位微控制器 ROM, RAM, CPU + I/O port 1980年Intel MCS-51, 8位微控制器 16位, 32位微处理器… 1990’s, DSP TMS320C30 嵌入式处理器的分类和术语(1) 微控制器(MCU：Micro-Controller Unit) 即单片机。早期比较