指纹识别专用IC中ZBT SRAM控制器设计

本文针对指纹识别专用IC设计的特点,设计采用了片外ZBT SRAM.文中提出指纹识别系统中ZBT SRAM总线仲裁策略并设计了ZBT SRAM的控制器,实现了数据流的无缝处理,为指纹识别系统的算法模块提供了符合流水线算法要求的数据存储.本文设计的ZBT SRAM控制器及总线仲裁策略已在Xilinx公司Virtex4系列FPGA-xc4vsx35上通过验证,满足指纹识别系统专用IC对其功能和时序的要求.     

基于VLIW体系结构的椭圆曲线密码专用指令处理器

The requirement of the flexible and effective implementation of the Elliptic Curve Cryptography (ECC) has become more and more exigent since its dominant position in the public-key cryptography application. Based on analyzing the basic structure features of Elliptic Curve Cryptography (ECC) algorithms, the parallel schedule algorithm of point addition and doubling is presented. And based on parallel schedule algorithm, the Application Specific Instruction-Set Co-Processor of ECC that adopting VLIW architecture is also proposed in this paper. The coprocessor for ECC is implemented and validated using Altera’s FPGA. The experimental result shows that our proposed coprocessor has advantage in high performance and flexibility.     

HRM: H-tree based reconfiguration mechanism in reconfigurable homogeneous PE array

In order to accommodate the variety of algorithms with different performance in specific application and improve power efficiency,reconfigurable architecture has become an effective methodology in academia and industry.However,existing architectures suffer from performance bottleneck due to slow updating of contexts and inadequate flexibility.This paper presents an H-tree based reconfiguration mechanism(HRM)with Huffman-coding-like and mask addressing method in a homogeneous processing element(PE)array,which supports both programmable and data-driven modes.The proposed HRM can transfer reconfiguration instructions/contexts to a particular PE or associated PEs simultaneously in one clock cycle in unicast,multicast and broadcast mode,and shut down the unnecessary PE/PEs according to the current configuration.To verify the correctness and efficiency,we implement it in RTL synthesis and FPGA prototype.Compared to prior works,the experiment results show that the HRM has improved the work frequency by an average of 23.4%,increased the updating speed by 2×,and reduced the area by 36.9%;HRM can also power off the unnecessary PEs which reduced 51%of dynamic power dissipation in certain application configuration.Furthermore,in the data-driven mode,the system frequency can reach 214 MHz,which is 1.68×higher compared with the programmable mode.     

Applications and improvement of H.264 in medical video compression

This paper aims at applying H.264 in medical video compression applications and improving the H.264 rate control algorithm with better perceptual quality. First, H.264 is briefly reviewed and introduced to the area of medical video compression. Second, a new motion complexity (MC) measure is defined to express the complexity of motion contents in a video frame, and a new H.264 rate control scheme with the MC measure and perceptual bit allocation is proposed for medical video compression. Third, two sets of experiments are conducted: the comparison between MPEG-4 and H.264, and the comparison between JVT-H014 , which is the H.264 adopted rate control algorithm, and our proposed rate control scheme. The first set of experiments shows that compared with MPEG-4, H.264 can achieve a significant average peak signal-to-noise ratio (PSNR) gain of up to 4.35 dB for the test medical video sequences, and thus is much more effective when applied in medical video compression. The second set of experiments shows that compared with H014, the proposed rate control scheme can achieve better perceptual video quality, with an average PSNR gain of up to 0.19 dB for the test medical video sequences.     

Design of an Embedded Arabic Optical Character Recognition

This work presents an embedded Arabic OCR system. The proposed system is compact and portable which make it useful for many applications such as blind assistance and language translation. OCR system consists of the sub-systems: image acquisition, pre-processing, segmentation, feature extraction, classification, and post- processing. For each sub-system there are several of algorithms and techniques to be implemented. Working with PCs gives the designer freedom to select the algorithms and techniques according to the required performance, reliability and reusability. However with the embedded systems we are facing many problems and challenges. Such challenges are associated with memory, speed, and computational power. FPGA is selected as the hardware platform for realizing that recognition task. An OCR system is designed and implemented on PC. Then this system is transferred to FPGA after a set of optimization procedures. Utilizing the features of FPGA technology, Hardware / Software co-design is accomplished on an FPGA board. In that design the systems is partitioned into software modules and hardware components to get the advantages of software flexibility and hardware speed. A database of 3000 Arabic characters is used to train and test the performance of the system. The effects of changing the number of features and classification parameters on accuracy, memory and speed are measured. Design points are selected in order to improve the memory required, speed and computation power without affecting the accuracy.     

FPGA and ASIC implementation of robust invisible binary image watermarking algorithm using connectivity preserving criteria

Digital watermarking is the process of hiding information into a digital signal to authenticate the contents of digital data. There are number of watermarking algorithm implemented in software and few in hardware. This paper discusses the implementation of robust invisible binary image watermarking algorithm in Field Programmable Gate Array (FPGA) and Application Specific Integrated Circuits (ASIC) using connectivity preserving criteria. The algorithm is processed in spatial domain. The algorithm is prototyped in (i) XILINX FPGA (ii) 130 nm ASIC. The algorithm is tested in Virtex-E (xcv50e-8-cs144) FPGA and implemented in an ASIC.     

一种改善H.263图像质量的方法

提出了一种保护图像中最重要的边缘信息的量化策略.仿真结果表明,与普通量化方法(如TMN系列代码)相比,新方法以较小的运算量为代价使边缘信息得到有效保护,从而在降低码率的同时更好地保持了图像的质量.     

基于与非锥的新型FPGA逻辑簇互连结构研究

该文针对新型FPGA可编程逻辑单元与非锥(And-Inverter Cone, AIC)的结构特性,提出一系列方案以得到优化的逻辑簇互连结构,包括:移除输出级交叉矩阵,单级反相交叉矩阵,低负载电路优化,将反馈和输出选择功能分开,限制AIC输出级数的基础上移除中间级交叉矩阵,与LUT架构进行混合等。通过大量的实验,得出针对面积延时积最优的AIC簇互连结构,与Altera公司的FPGA芯片Stratix-IV结构相比,该结构逻辑功能簇本身面积减小9.06%, MCNC应用电路集在基于优化的AIC FPGA架构上实现的平均面积延时积减小40.82%, VTR应用电路集平均面积延时积减小17.38%;与原有的AIC结构相比,簇面积减小23.16%, MCNC应用电路集平均面积延时减小27.15%, VTR应用电路集平均面积延时积减小15.26%。     

H.264解码器的ASIC解决方案及其FPGA验证平台

论述了H.264解码器的ASIC(专用芯片)解决方案及其FPGA验证平台.该方案比常见DSP解决方案有更快的解码速度和更低的能耗,解决了H.264解码器由于算法复杂性增大带来的速度和能耗问题.鉴于大规模SoC芯片验证的复杂性,还比较详细地介绍了该芯片基于FPGA的验证平台.     

Flexibility of interconnection structures for field-programmablegate arrays

The relationship between the routability of a field-programmable gate array (FPGA) and the flexibility of its interconnection structures is examined. The flexibility of an FPGA is determined by the number and distribution of switches used in the interconnection. While good routability can be obtained with a high flexibility, a large number of switches will result in poor performance and logical density because each switch has significant delay and area. The minimum number of switches required to achieve good routability is determined by implementing several industrial circuits in a variety of interconnection architectures. These experiments indicate that high flexibility is essential for the connection block that joins the logic blocks to the routing channel, but a relative low flexibility is sufficient for switch blocks at the junction of horizontal and vertical channels. Furthermore, it is necessary to use only a few more routing tracks than the absolute minimum possible with structures of surprisingly low flexibility     

High speed interconnect through device optimization for subthreshold FPGA

Field programmable gate array (FPGA) consumes a significant amount of static and dynamic power due to the presence of additional logic for providing more flexibility as compared to application specific integrated circuits (ASICs). The fabrication cost of ASICs is rising exponentially in deep submicron and hence it is important to investigate different techniques for reducing FPGA power consumption so that they can also be employed in place of ASICs in portable energy constrained applications. It is also important to investigate the possibility of extending the use of FPGA even to subthreshold region for ultra low power (ULP) applications. Interconnect resources of an FPGA consumes most of the chip power, area and also determines the overall circuit delay. Subthreshold circuits show orders of magnitude power saving over superthreshold circuits. Improving the performance of subthreshold circuits is a main design challenge at the circuit and device levels to spread their application area. This paper proposes to improve the performance of subthreshold FPGA in terms of delay and switching energy by optimizing and operating interconnect drivers in the near threshold operating region. The possibility of inserting repeaters and the suitability of CNT as an interconnect in the subthreshold region are also explored. The simulation of FPGA interconnect resources using the proposed technique shows 67%, 73.33% and 61.8% increase in speed and 35.72%, 39% and 35.44% reduction in switching energy for Double, Hex and Long interconnect segments, respectively, over the conventional one.     

FPGA-based Physical Unclonable Functions: A comprehensive overview of theory and architectures

Physically Unclonable Functions (PUFs) are a promising technology and have been proposed as central building blocks in many cryptographic protocols and security architectures. Among other uses, PUFs enable chip identifier/authentication, secret key generation/storage, seed for a random number generator and Intellectual Property (IP) protection. Field Programmable Gate Arrays (FPGAs) are re-configurable hardware systems which have emerged as an interesting trade-off between the versatility of standard microprocessors and the efficiency of Application Specific Integrated Circuits (ASICs). In FPGA devices, PUFs may be instantiated directly from FPGA fabric components in order to exploit the propagation delay differences of signals caused by manufacturing process variations. PUF technology can protect the individual FPGA IP cores with less overhead. In this article, we first provide an extensive survey on the current state-of-the-art of FPGA based PUFs. Then, we provide a detailed performance evaluation result for several FPGA based PUF designs and their comparisons. Subsequently, we briefly report on some of the known attacks on FPGA based PUFs and the corresponding countermeasures. Finally, we conclude with a brief overview of the FPGA based PUF application scenarios and future research directions.     

基于可重构核的FPGA电路设计

电路系统的自适应性、紧凑性和低成本 ,促进了在嵌入式系统中软硬件的协同设计。在线可重构FPGA不仅可以满足这一要求 ,而且在可编程专用电路系统设计的验证及可靠性等方面有着良好的应用 ,文中介绍了可重构 FPGA的实现结构及评估方法 ,提出以线性矢量表征可重构 FPGA及其可重构核的研究模型 ,以及基于可重构核的模块化设计 ,认为面向分类的专用类可重构 FPGA应当是现阶段可重构 FPGA的研究主题。     

Stateful-NOR based reconfigurable architecture for logic implementation

Most commercial Field Programmable Gate Arrays (FPGAs) have limitations in terms of density, speed, configuration overhead and power consumption mostly due to the use of SRAM cells in Look-Up Tables (LUTs), configuration memory and programmable interconnects. Also, hardwired Application Specific Integrated Circuit (ASIC) blocks designed for high performance arithmetic circuits in FPGA reduce the area available for reconfiguration. In this paper, we propose a novel generalized hybrid CMOS-memristor based architecture using stateful-NOR gates as basic building blocks for implementation of logic functions. These logic functions are implemented on memristor nanocrossbar layers, while the CMOS layer is used for selection and connection of memristors. The proposed pipelined architecture combines the features of ASIC, FPGA and microprocessor based designs. It has high density due to the use of nanocrossbar layer and high throughput especially for arithmetic circuits. The proposed architecture for three input one output logic block is compared with conventional LUT based Configurable Logic Block (CLB) having the same number of inputs and outputs; which shows 1.82×area saving, 1.57×speedup and 3.63×less power consumption. The automation algorithm to implement any logic function using proposed architecture is also presented.     

Highly efficient, limited range multipliers for LUT-based FPGA architectures

A novel design technique for deriving highly efficient multipliers that operate on a limited range of multiplier values is presented. Using the technique, Xilinx Virtex field programmable gate array (FPGA) implementations for a discrete cosine transform and poly-phase filter were derived with area reductions of 31%-70% and speed increases of 5%-35% when compared to designs using general-purpose multipliers. The technique gives superior results over other fixed coefficient methods and is applicable to a range of FPGA technologies.     

岛式FPGA全局信号网络的优化设计

针对使用拼接单元块设计方法的岛式FPGA,介绍了一种交叉连接的方法,可以为其全局信号网络的缓冲器插入提供可变性. 对于采用此方法设计的全局信号网络,文中的穷举算法定量分析了其面积和性能之间相互影响的关系,并提出了量化的标准,用于选择设计参数使面积和性能达到均衡. 通过对比常用方法和文中方法所得到的全局信号网络的性能,证明文中方法在较大的FPGA芯片中能够得到更优的结果.     

岛式FPGA全局信号网络的优化设计

针对使用拼接单元块设计方法的岛式FPGA,介绍了一种交叉连接的方法,可以为其全局信号网络的缓冲器插入提供可变性.对于采用此方法设计的全局信号网络,文中的穷举算法定量分析了其面积和性能之间相互影响的关系,并提出了景化的标准,用于选择设计参数使面积和性能达到均衡.通过对比常用方法和文中方法所得到的全局信号网络的性能,证明文中方法在较大的FPGA芯片中能够得到更优的结果.     

A bi-criteria minimum spanning tree routing model for MPLS/overlay networks

The MPLS platform enables the implementation of advanced multipath and multicast routing schemes. This work develops and analyses the performance of a new bi-criteria minimum spanning tree model intended for routing broadcast messages in MPLS networks or constructing tree-based overlay networks. The aim of the model is to obtain spanning trees which are compromise solutions with respect to two important traffic engineering metrics: load balancing cost and average delay bound. An exact solution to the formulated bi-criteria optimization problem is presented, which is based on an algorithm that enables the computation of the set of supported non-dominated spanning trees. An application model and a set of experiments on randomly generated Internet type topologies will also be presented. Finally a network performance analysis of the model considering three network performance metrics will be shown.     

面向AIC结构的FPGA映射工具

探索新的现场可编程门阵列(FPGA)逻辑单元结构一直是FPGA结构研究的重点方向,与非逻辑锥(AIC)作为一种新的逻辑结构成为FPGA新结构的希望。然而实现高效且灵活的映射工具同样是研究FPGA新结构中的重点环节。该文实现了一个面向AIC结构的FPGA映射工具,与当前映射工具相比,具有更高的灵活性,能够支持AIC结构参数的调节,辅助支持进行AIC单元结构的探索改进。同时,该文提出的AIC映射工具与原工具相比,面积指标提高了33%~36%。     

Application Domain Specific Embedded FPGAs for Flexible ISA-Extension of ASIPs

This paper presents a novel architecture combining an application specific instruction set processor (ASIP) core and an application domain specific embedded FPGAs (eFPGAs) used as flexible accelerator for the ASIP. The eFPGA is based on a parametrisable architecture template optimised for arithmetic oriented applications. It was designed as a physically optimised VLSI-macro using a flexible design methodology also sketched in this paper. Quantitative comparisons of the eFPGA with a commercial standard FPGA show significant improvements in energy, area and timing delays. Simulations of the new ASIP-eFPGA architecture have been conducted using a model based approach to evaluate its efficiency. The results show that power- and area-efficiencies similar to an FPGA can be achieved for the flexible ASIP-eFPGA while preserving the flexibility of a software programmable processor.