嵌入式系統(Embedded system)也稱嵌入式計算機系統。顧名思義,嵌入式系統是計算機的一種特殊形式,所以在理解嵌入式系統概念前,必須先明確計算機的基本概念。計算機是能按照指令對各種數據進行自動加工處理的電子設備,一套完整的計算機系統包括硬件和軟件兩個部分。軟件是指令與數據的集合,而硬件則是執行指令和處理數據的環境平臺,是那些看得見、摸得著的部件。計算機的硬件系統主要由中央處理器(CPU)、存儲器、外部設備以及連接各個部分的計算機總線組成。
上傳時間: 2013-11-23
上傳用戶: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
上傳時間: 2013-10-29
上傳用戶:康郎
在研究傳統家用燃氣報警器的基礎上,以ZigBee協議為平臺,構建mesh網狀網絡實現網絡化的智能語音報警系統。由于傳感器本身的溫度和實際環境溫度的影響,傳感器標定后采用軟件補償方法。為了減少系統費用,前端節點采用半功能節點設備,路由器和協調器采用全功能節點設備,構建mesh網絡所形成的家庭內部報警系統,通過通用的電話接口連接到外部的公用電話網絡,啟動語音模塊進行報警。實驗結果表明,在2.4 GHz頻率下傳輸,有墻等障礙物的情況下,節點的傳輸距離大約為35 m,能夠滿足家庭需要,且系統工作穩定,但在功耗方面仍需進一步改善。 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.
上傳時間: 2013-10-30
上傳用戶:swaylong
為了能夠滿足基站易于選址、優質快速的建站要求和易維護、低成本、高可靠的運行要求,本文對以方艙來實現一體化結構基站做出一番探討。從系統設計的觀點闡述了移動通信高性能基站天線設計的幾個關鍵問題,介紹了智能天線技術在基站中的應用,并且用HFSS軟件仿真了一種新型的對稱陣子天線,該天線駐波比小于2的帶寬可以達到60%,具有良好的寬頻帶特性。 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.
上傳時間: 2013-11-20
上傳用戶:linlin
通過以太網遠程配置Nios II 處理器 應用筆記 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.
上傳時間: 2013-11-22
上傳用戶: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.
上傳時間: 2013-10-22
上傳用戶: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.
標簽: application describe elements purpose
上傳時間: 2013-12-29
上傳用戶:sxdtlqqjl
我們做微機硬件綜合實驗做的一個交通信號燈實時控制系統設計,很好哦!還附有實驗報告.-A traffic lights real-time control system design of the micro computer hardware experiment.PS:contain the experiment report
上傳時間: 2015-11-17
上傳用戶: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.
標簽: authenticated TinyLogin utilities handling
上傳時間: 2016-01-30
上傳用戶:253189838
be文件系統實現的源碼,其配套資料為Practical File System Design
上傳時間: 2013-12-30
上傳用戶:woshini123456