一种高度并行无乘法器结构的二维IDCT协处理器设计

介绍了一种适用于MPEG-4视频简单层解压缩应用的二维IDCT协处理器。该处理器采用Loeffler架构的IDCT快速算法,并使用加法和移位运算代替IDCT快速算法中的浮点乘法运算单元,用高度并行流水VLSI结构加快数据处理速度,采用一维的IDCT单元的复用的方式来实现二维的IDCT运算。在满足处理速度和精度要求的基础上,利用较少的晶体管数目实现了一种高性能的二维IDCT处理器。该方案已经应用于一款SOC芯片中的硬件MMA(多媒体加速单元)中,IDCT的运算精度也得到了验证。     

JPEG解码器IP核的设计与实现

介绍了基于静止图像压缩标准JPEG解码器IP核的设计与实现.设计采用适于硬件实现的IDCT算法结构,通过增加运算并行度和流水线技术相结合的方法以提高处理速度.根据Huffman码流特点,采用新的Huffman并行解码硬件实现结构,用简单的算术运算代替复杂的配对模式,解码速度快,硬件成本低.该IP核可方便地集成到诸如数码...     

嵌入式系统中MPEG-4解码IDCT的硬件实现和验证

离散余弦反变换(IDCT)广泛应用于MPEG-4等视频压缩、解压缩应用中。在嵌入式系统中,IDCT运算的效率将直接影响MPEG-4实时解码性能。文中根据嵌入式系统的特点,提出了一种新的IDCT硬件实现方法,并采用了一种新的验证手段对该硬件实现进行了全方位的验证。该方案已经应用于一款SoC芯片中的硬件MMA(多媒体加速单元)中。     

基于流水的HEVC IDCT/IDST模块VLSI设计

2013年1月HEVC(High Efficient Video Coding)被ITU-T和ISO/IEC正式确立为新一代视频编码国际标准.为了实现更高的压缩效率,HEVC使用了多项新技术.在空间域变换方面,HEVC支持从4×4到32×32的可变尺寸的IDCT变换,同时根据模式进行4×4IDCT和IDST变换的选择.由此提出了一种HEVC IDCT/IDST变换架构.采用基于流水的数据流调度策略和系数矩阵优化方案,提升了硬件效率和接口带宽利用率.采用65nm工艺库综合后,一维IDCT/IDST单元的等效门数约为40K,最高工作频率为500MHz,与现有设计相比可以实现30%以上的硬件资源减少和60%以上的吞吐率效率提升.仿真结果显示该结构可以实现对4k×2k@30f/s视频的IDCT/IDST处理.     

运动估计协处理器的设计

设计了一个运动估计协处理器,用来从硬件的角度解决图像匹配的实时性问题.首先介绍图像处理中的运动估计技术,然后介绍运动估计技术中常用的块匹配算法及判据的选择,最后详细介绍了运动估计协处理器的设计及其实现.     

一种新型2-DCT/IDCT结构的设计与实现

本文根据MPEG-2视频编码的特点,设计了仅由一个1-DCT核完成的2-DCT/IDCT结构,该结构的转换矩阵通过SRAM实现,具备双端口的输入输出,数据吞吐率较高,能够有效节省芯片面积.1-DCT核由7个乘法器组成,乘法器可以根据计算速度的快慢灵活设计.为了解决双端口无冲突的存储访问,提出了一个数据排列方案.由于乘法器的乘数之一为常数,我们设计了一种常数修改方案能够有效的降低成法器的硬件开销.该2-DCT/IDCT结构通过了FPGA验证,具有较强的工程实用价值.     

用于无线传感器网络的MAC控制加速器的设计

提出了一种基于协处理器的MAC控制加速器体系结构,其特点是兼容于IEEE802.15.4协议,还能支持S-MAC、T-MAC等其它无线传感器网络MAC协议,增强了硬件的可扩展性;阐述了协处理器实现CSMA-CA算法、S-MAC和T-MAC协议的方法,并在此基础上分析了协处理器实现的CSMA-CA算法的软件时延;在FPGA上实现了整个MAC控制加速器的设计.测试结果表明:该MAC支持20~250kbps数据传输速率,支持多协议,适应IEEE802.15.4协议要求,面积仅为30567个等效门.     

基于DA的高性能2-D IDCT处理器设计

为提高2-D IDCT的解码速度,文中设计了一种基于DA的2-D IDCT处理器.该处理器在算法上用1-D IDCT实现2-D IDCT,用Chen算法实现1-D IDCT,用DA实现乘加结构.通过将输入数据分成高6位和低6位两组加快了处理器的速度,通过查找表的共用及将输入数据投影到(-1,1)的编码减少了查找表的数量及大小.通过在Q0上预存四舍五入值省去了四舍五入所需的加法运算.使用Altera的EP2C20F484C7对该处理器进行综合,时钟最高频率可达165.37MHz.     

一种基于高度并行结构的二维DCT/IDCT处理器设计

本文介绍一种适用于MPEG-4视频简单层(Simple Profile Layer1-3)压缩编码的二维88 DCT/IDCT处理器设计,该处理器设计充分利用DCT与IDCT的相似性及算法对称性,用高度的并行结构来加快处理速度,采用一维DCT/IDCT单元复用的方式来实现二维DCT/IDCT运算和简化的乘法器设计,在满足处理速度和精度要求的基础上,利用较少的晶体管数目实现了一种高性能二维DCT/IDCT处理器。     

一种新的算法可编程的运动估计协处理器

本文针对块匹配运动估计快速搜索算法的要求,设计了一种算法可编程的运动估计及运动补偿协处理器。该协处理器设计采用软硬件协同处理结构。灵活的指令集和高效的硬件并行执行单元相结合,使得该协处理器具备可编程处理器结构及树形结构运动估计VLSI结构的优点,可以兼顾运动估计算法高处理效率和灵活性的要求。设计的协处理器不拘泥于某种快速搜索算法,通过改变内部程序代码,可以实现多种快速运动估计算法,包括TSS、DS、HEXBS、MVFAST、EPZS等,同时具备很强的可扩展性。与同类设计相比,本设计具有高效、灵活、算法可配置的特点,同时设计消耗的硬件资源也大幅减小。     

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.