基于PCI-Express的高速数据交换设计及应用

提出了利用PCIE总线技术实现数据高速传输的方案,结合共享内存、DMA等技术设计了基于PCI—Express总线的高速数据传输卡．实现了将采集的数据实时传送到PC的共享内存缓冲区,数据传输采用DMA方式。采用接口器件PEX8111实现PCI—Express总线到PCI总线的桥接。使用FPGA编写PCI总线的接口逻辑,最后进行测试。     

基于PCI-Express的高速数据交换设计及应用

提出了利用PCIE总线技术实现教据高速传输的方案,结合共享内存、DMA等技术设计了基于PCI-Express总线的高速数据传输卡,实现了将采集的数据实时传送到PC的共享内存缓冲区,数据传输采用DMA方式.采用接口器件PEX8111实现PCI-Express总线到PCI总线的桥接.使用FPGA编写PCI总线的接口逻辑,最后进行测试.     

GaAs binary frequency dividers for high speed applications up to 10 GHz

Very high speed GaAs frequency dividers with a maximum operating frequency of 10 GHz are proposed. The dividers are based on a two-phase dynamic logic concept. Breadboard and simulation results are presented and discussed.     

汽车与工业应用催生DSP+MCU合成控制器

DSP与MCU产品在应用之初,可谓是泾渭分明--DSP由于其出色的运行各种高密度算法的能力,被施用于需要大量数据处理的领域;而MCU则扮演着电子设备控制核心的角色,协调各系统和显示、键盘、传感器、电机等周边器件的操作.但时至今日,电子系统对其控制核心的要求越来越高,特别是在汽车电子和工业控制领域,在完成日益复杂的控制功能的同时,微控制器往往还要承担越来越多的数据计算、信号处理的工作,因此需要一种能够同时具备传统DSP与MCU双重功能的新型的控制器件.     

Lasers speed up board production

A technology for writing conductor patterns directly on photoresist simplifies the manufacture of printed-circuit boards and also multiplies yields. If a laser beam is switched on and off as it scans, it can be made to trace a pattern on a light-sensitive material directly, without intervening steps. There is no need to prepare a photonegative, or phototool, to block light from background regions, as is done at present in "printing" circuit boards. The laser can scan conductors directly on photoresist covering an embryonic copper-clad nonconductive circuit board; subsequent board processing remains conventional-developing the resist, exposing and etching part of the copper surface, and removing the rest of the resist. In this way, the up-and-coming laser direct imaging (LDI) systems eliminate the need for a phototool and thereby slash production time of circuit board prototypes by at least one half. So far, several manufacturers of prototypes and medium volumes of printed-circuit boards (about 100 m² per day) have adopted LDI. In contrast with older technologies, LDI can produce even large panels (up to 750 mm by 600 mm) with fine features (conductor lines and spaces, for example) at high yields     

Energy-Efficient Considerations on a Variable-Bitrate PCI-Express Device

Dynamic power management has been adopted in many systems to reduce the power/energy consumption by changing the system state dynamically. This paper explores energy efficiency for systems equipped with PCI-Express devices, which are designed for low power consumption and high performance, compared to corresponding PCI devices. We propose dynamic power management mechanism and a management policy for energy-efficient considerations. A case study for a variable-bit-rate local-area-network device under the PCI-Express specification is exploited to provide supports for dynamic packet transmission. Simulation results show that the proposed mechanism and policy would reduce the system energy consumption substantially.     

一种改进的快速鲁棒性特征匹配算法

针对光照变化、噪声、局部遮挡等在图像配准技术中对配准精度有重要影响,提出了一种在多尺度空间下点预测快速鲁棒性不变特征的匹配算法。针对在探测对图像的尺度、旋转,仿射具有不变性的斑状特征极值点过程中计算复杂度较高的问题,提出一种特征点预测方法降低了描述子提取的复杂度,增强了对外部环境光照变化、噪声以及局部遮挡的适应能力;并在KD(KD Tree)树基础上,提出了一种动态平衡KD树(DBKD-Tree)快速搜索匹配算法,有效克服了KD树可能存在的病态划分,采用条件约束最邻近搜索,提升匹配效率,实现特征点高精度匹配。通过对在不同光照条件、噪声环境的仿射变换图像特征匹配测试,在加入20%的高斯噪声后,均能100%地完成重复特征检测,达到亚像素定位精度,误配率降低为零。     

通过LabVIEW FPGA加速嵌入式系统原型化的过程

嵌入式系统的发展趋势 嵌入式系统一般是指一个独立且具有专门用途的系统，随着半导体技术的飞速发展，嵌入式系统正在渗入现代社会的各个方面，被广泛应用于航空航天、通信设备、消费电子、工业控制、汽车、船舶等领域。巨大的市场需求推动了嵌入式系统向更高的技术水平发展。