视音频延时器用大容量FIFO的设计

介绍视音频延时器用大容量FIFO的设计,大容量FIFO的设计采用了SDRAM代替双口RAM,并采用FPGA设计双口SDRAM控制器.该FIFO也可用作高速数据采集系统的数据缓冲.     

基于FPGA的视频采集显示系统

设计实现一种基于FPGA的视频采集显示系统,包括视频图像的采集、处理与显示3个部分。视频图像部分采用CCD摄像头OV7670作为视频数据的采集,利用在FPGA中构建FIFO并配合SDRAM高速读写实现视频图像数据的高速缓存处理,使用FPGA中构建的Nios II嵌入式内核,实现对SDRAM的控制以及视频数据的TFT液晶实时显示。整个系统获得了较好图像采集、显示效果。     

高分辨率视频图像处理中SDRAM控制器的设计

本文介绍了一种基于FPGA的用于高分辨率视频图像处理的SDRAM控制器的设计方法。通过设置SDRAM的工作状态,使其工作在猝发模式。在视频时序信号控制下,用多行连续的SDRAM存储空间,存取视频数据。并在数据接口部分增加FIFO,缓存一行视频,在像素时钟控制下,实现视频数据实时的存储和读取。通过改变相关参数,能对所有VESA分辨率视频流进行操作。具有通用性强、系统复杂度低、可靠性高、可扩展等特点。在某型号的机载大屏显示器系统中,用该SDRAM控制器实现了图像的翻转等功能,也验证了该控制器的实用性。     

高速大容量FIFO的设计

为了解决标清数字视频的帧同步器中的帧缓冲器设计问题,文中描述了一种可以支持实时数据流处理的高速大容量FIFO设计方法.该方法用SDRAM做为存储体,用FPGA设计双口SDRAM状态机控制SDRAM工作,并在FPGA内部实现数据接口同步,对数据流进行流水线式处理,完成数据的无缝缓冲,保证输入输出数据流的连续性.通过下载调试,该FIFO设计方法可用做视频帧同步器中的帧缓冲器.     

基于FPGA的高速大容量异步FIFO的实现

为了实现测试光纤陀螺仪的大量的数据采集,提出了一种基于FPGA的高速大容量异步FIFO控制器的实现方法,分析了所用SDRAM的特点和工作流程,设计出了实现这种控制器的方法。最后给出了SDRAM控制器的写数据仿真结果图。此设计基本满足了测试光纤陀螺仪数据采集和数据存储的要求。设计中采用SDRAM作为FIFO缓冲器,利用FPGA实现对SDRAM的控制。这种方法通用性好且成本低,可以应用在任何一种有大容量数据缓冲要求的系统中。     

FPGA和以太网的实时视频图像传输系统

<正>为了实现对高清视频图像的实时稳定的传输,基于当前成熟高速可靠稳定的以太网,结合具有强大并行处理能力的FPGA设计了一种基于FPGA和以太网的实时视频传输系统。该系统主要采用了Altera公司的Cyclone Ⅳ系列FPGA开发板,OV5640摄像头作为视频图像数据采集口,数据通过SDRAM读写FIFO,写入读出SDRAM,以太网数据通信模块读出数据后进行数据格式封装,经过RJ45以太网接口,最终视频图像在显示器上显示。     

多FIFO灵活定制SDRAM控制器设计

针对SDRAM控制器设计复杂且可复用性低的特点,基于VerilogHDL提出了一种简单且可灵活定制异步FIFO的SDRAM控制器实现。图像预处理时经常会用到SDRAM来作为缓存,SDRAM的工作频率很高,所以一般会用异步FIFO缓存数据匹配它的频率,但是每次都重新设计FIFO的控制显然太繁琐。本设计结合FPGA的特点一方面简化SDRAM的控制时序提高了系统性能,另一方面在控制器中嵌入多路异步FIFO,当面对不同的设计需要时只需给设计关心的异步FIFO加载上数据、时钟、深度以及地址则可。既节约了逻辑资源又实现了重复使用的目的为后续设计节省了时间。     

视频图像处理系统CPLD控制和EDMA数据搬移的实现

介绍一种视频图像的采集和处理系统.系统由CCD摄像头、视频解码芯片SAA7111、可编程逻辑芯片CPLD、先进先出FIFO存储器,以及数字信号处理器DSP等组成.详细讨论CPLD对图像采集速度和数量的控制及LEDMA图像数据搬移的实现方法.实践证明,该系统可以精确地控制图像大小,CPU可以专注于图像处理,而频繁的数据从FIFO到外部SDRAM、SDRAM到内部RAM的搬移工作完全交给EDMA在后台实现,提高了图像数据的传输效率,充分发挥DSP的高性能,使得系统设计简捷清晰,调试极为方便.     

基于FPGA的高速海量FIFO的设计

为了解决视频信号的大量存储及视频延时问题,研究了一种以DDR2 SDRAM为存储体的高速海量FIFO设计方法.该方法通过采用FPGA对DDR2 SDRAM进行控制,以状态机来描述其各种时序操作,来完成DDR2 SDRAM的命令和数据的接口,从而实现数据的正确有序的存取.另外,流水式处理的方式,也保证了输入输出数据的连续性.经过最终硬件的成型和下栽调试,验证了该方法的可行性和可靠性.该系统已经成功应用于视频的延时处理.     

嵌入式实时图像处理系统中SDRAM控制器的实现

介绍一种用于嵌入式实时图像处理系统的SDRAM控制器的实现方案.根据实时系统对数据传输速率及连续性的要求,将SDRAM配置为全页突发操作模式,并采用异步FIFO作为FPGA与SDRAM间的数据缓冲器.为配合SDRAM的全页操作模式,并充分利用其高速读写性能,将FIFO设计为基于乒乓操作的流水线结构,实现了数据的无缝缓存.将该方案用于实时红外热成像系统,经实验结果表明,该SDRAM控制器执行效率高,占用资源少,可移植性强.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.