嵌入式系统(Embedded system)也称嵌入式计算机系统。顾名思义,嵌入式系统是计算机的一种特殊形式,所以在理解嵌入式系统概念前,必须先明确计算机的基本概念。计算机是能按照指令对各种数据进行自动加工处理的电子设备,一套完整的计算机系统包括硬件和软件两个部分。软件是指令与数据的集合,而硬件则是执行指令和处理数据的环境平台,是那些看得见、摸得着的部件。计算机的硬件系统主要由中央处理器(CPU)、存储器、外部设备以及连接各个部分的计算机总线组成。
上传时间: 2013-11-23
上传用户:qwerasdf
Abstract: This article discusses the benefits of a G3-PLC-based automation system and presents a real-world example of a systemfor reducing energy usage and lowering maintenance costs in tunnels. The basic system design is explained and key performance
上传时间: 2013-10-29
上传用户:康郎
在研究传统家用燃气报警器的基础上,以ZigBee协议为平台,构建mesh网状网络实现网络化的智能语音报警系统。由于传感器本身的温度和实际环境温度的影响,传感器标定后采用软件补偿方法。为了减少系统费用,前端节点采用半功能节点设备,路由器和协调器采用全功能节点设备,构建mesh网络所形成的家庭内部报警系统,通过通用的电话接口连接到外部的公用电话网络,启动语音模块进行报警。实验结果表明,在2.4 GHz频率下传输,有墙等障碍物的情况下,节点的传输距离大约为35 m,能够满足家庭需要,且系统工作稳定,但在功耗方面仍需进一步改善。 Abstract: On the basis of studying traditional household gas alarm system, this paper proposed the platform for the ZigBee protocol,and constructed mesh network to achieve network-based intelligent voice alarm system. Because of the sensor temperature and the actual environment temperature, this system design used software compensation after calibrating sensor. In order to reduce system cost, semi-functional node devices were used as front-end node, however, full-function devices were used as routers and coordinator,constructed alarm system within the family by building mesh network,connected to the external public telephone network through the common telephone interface, started the voice alarm module. The results indicate that nodes transmit about 35m in the distance in case of walls and other obstacles by 2.4GHz frequency transmission, this is able to meet family needs and work steadily, but still needs further improvement in power consumption.
上传时间: 2013-10-30
上传用户:swaylong
为了能够满足基站易于选址、优质快速的建站要求和易维护、低成本、高可靠的运行要求,本文对以方舱来实现一体化结构基站做出一番探讨。从系统设计的观点阐述了移动通信高性能基站天线设计的几个关键问题,介绍了智能天线技术在基站中的应用,并且用HFSS软件仿真了一种新型的对称阵子天线,该天线驻波比小于2的带宽可以达到60%,具有良好的宽频带特性。 Abstract: In order to meet the station construction requirement of easy site selection and fast base station, and meet the operational requirement of easy maintenance, low cost and high reliability, this paper discussed the unified architecture base station using shelter. Several key problems of high performance mobile communication base station antenna were illustrated from the view of system design, the application of smart antenna in base station was also introduced. And a novel dipole antenna was simulated by using HFSS, the VSWR of the antenna is less than 2, and the bandwidth was reach to 60%. So it has good broadband properties.
上传时间: 2013-11-20
上传用户:linlin
通过以太网远程配置Nios II 处理器 应用笔记 Firmware in embedded hardware systems is frequently updated over the Ethernet. For embedded systems that comprise a discrete microprocessor and the devices it controls, the firmware is the software image run by the microprocessor. When the embedded system includes an FPGA, firmware updates include updates of the hardware image on the FPGA. If the FPGA includes a Nios® II soft processor, you can upgrade both the Nios II processor—as part of the FPGA image—and the software that the Nios II processor runs, in a single remote configuration session.
上传时间: 2013-11-22
上传用户:chaisz
Field Programmable Gate Arrays (FPGAs) are becoming a critical part of every system design. Many vendors offer many different architectures and processes. Which one is right for your design? How do you design one of these so that it works correctly and functions as you expect in your entire system? These are the questions that this paper sets out to answer.
上传时间: 2013-10-22
上传用户:lmq0059
The purpose of this application note is to describe the main elements of an RS-422 and RS-485 system. This application note attempts to cover enough technical details so that the system designer will have considered all the important aspects in his data system design. Since both RS-422 and RS- 485 are data transmission systems that use balanced differential signals, it is appropriate to discuss both systems in the same application note. Throughout this application note the generic terms of RS-422 and RS-485 will be used to represent the EIA/TIA-422 and EIA/TIA-485 Standards.
标签: application describe elements purpose
上传时间: 2013-12-29
上传用户:sxdtlqqjl
我们做微机硬件综合实验做的一个交通信号灯实时控制系统设计,很好哦!还附有实验报告.-A traffic lights real-time control system design of the micro computer hardware experiment.PS:contain the experiment report
上传时间: 2015-11-17
上传用户:924484786
TinyLogin is a suite of tiny Unix utilities for handling logging into, being authenticated by, changing one s password for, and otherwise maintaining users and groups on an embedded system. It also provides shadow password support to enhance system security. TinyLogin is, as the name implies, very small, and makes an excellent complement to BusyBox on an embedded System. It can be used without BusyBox, of course, but I envision them being used together most of the time.
标签: authenticated TinyLogin utilities handling
上传时间: 2016-01-30
上传用户:253189838
be文件系统实现的源码,其配套资料为Practical File System Design
上传时间: 2013-12-30
上传用户:woshini123456