原理图输入方法设计32位超前进位加法器

本文介绍了用原理图输入方法设计一款图象处理ASIC芯片中乘加单元的核心运算部件——32位超前进位加法器，出于速度(时延)和面积折衷优化考虑，它以四位超前进位加法器和四位超前进位产生器为基本设计单元级联而成，因此该电路具有速度和面积的折衷优势。选择原理图输入方法，是考虑到本电路复杂度不高，而原理图输入可控性好，效率高，可靠性强且直观，可以熟悉较底层的结构。文章先给出电路的设计实现，并且是先设计四位超前进位加法器，再提出32位超前进位加法器的设计思想和设计原理，然后再通过测试文件的逻辑验证正确。本设计的所有内容，都将在SUN工作站上Cadence工具Schematic Composer中完成。     

一种多功能阵列乘法器的设计方法

为了实现不同数制的乘法共享硬件资源，提出了一种可以实现基于IEEE754标准的64位双精度浮点与32位单精度浮点、32位整数和16位定点的多功能阵列乘法器的设计方法。采用超前进位加法和流水线技术实现乘法器性能的提高。设计了与TMS320C6701乘法指令兼容的乘法单元，仿真结果验证了设计方案的正确性。     

预处理进位选择加法器

本文所介绍的加法器,吸取了先行进位加法器与条件和加法器的特点,在逻辑构思上和设计方法上有别于传统的加法器,速度达到和超过目前最快的先行进位加法器,其中检测信号的形成更快。文中讨论了加法器的原理、特点以及检测方法,对加法器的和与进位公式以及检测公式作了系统的推导。最后用本文提出的设计思想,用109D系列集成电路为某机设计了一个24位长的加法器,实际运行证明,原理正确,速度满足设计要求。     

VLIW数字信号处理器64位可重构加法器的设计

描述了一款适用于超长指令字数字信号处理器的64位加法器的设计。该加法器高度可重构，可以支持2个64位数据的加法运算、4个32位数据的加法运算、8个16位数据的加法运算以及16个8位数据的加法运算。它结合了Brent-Kung对数超前进位加法器和进位选择加法器的优点，使得加法器的面积和连线减少了50%，而延时与加法器的长度的对数成正比。仿真结果表明，在典型工作条件下，采用0.18μm工艺库标准单元，其关键路径的延时为0.83ns，面积为0.149mm2，功耗仅为0.315mW。     

高性能数字信号处理器的设计

本文完成了16位的数字信号处理器的设计，该数字信号处理器设计了针对信号处理的指令与体系结构，指令数为88条，综合后数字信号处理器的内核单元数为12799。十六位定点数字信号处理器为单发射系统，采用了多数据和地址总线设计，使四级流水在流水线的四个周期保持正常的数据流动，分散的寄存器形式结构，使多数指令在一周期内得到完成。数字信号处理器包含了中央算术逻辑单元、乘法器单元、移位器单元、排序器单元、辅助寄存器单元、中断单元的设计。在中央算术逻辑单元中，完成加／减运算以及逻辑运算，在进位链中采用了选择进位链，对数据溢出采用了饱和处理的方法；在乘法器单元中采用BOOTH算法和先进进位加法器相结合的单元设计；在排序器设计中，按照中断、指令第二指令字、累加器、堆栈等不同的程序排序源设计不同的通路，并按照ZLVC的条件，设计了条件转移指令；在辅助寄存器单元选择一条与正向进位相反方向的进位来实现FFT算法位反序要求；在中断单元中，采用二级中断，大堆栈保存地址，流水“冲刷”技术。     

惠普 新至强选配PCI-E

惠普已经在美国发布了多款双路服务器,包括ProLiant DL380G4、ProLiant DL360G4、ProLiant ML370G4、ProLiant ML350G4以及ProLiant BL20p G3等。据悉,这几款产品都采用了新至强处理器,可以支持32位/64位应用。其中,Proliant DL380G4是一款2U机架式服务器,处理器主频从3.4GHz～3.6GHz,其最大内存数为12GB,最多可配置6个内置硬盘。传统PCI、PCI-X插槽是该产品的标准配置,用户可以选择PCI Express扩展部件。ProLiant DL360G4是一款1U机架式服务器,处理器主频从3.0GHz～3.4GHz,最大内存数为8GB。据悉,该产品分为应用S…     

基于CSD编码的16位并行乘法器的设计

文中介绍了二进制数的CSD(Canonic Signed-Digit)编码技术;针对目前CSD编码大都是用软件预先求得或基于查找表实现,本文设计了一种有/无符号二进制数的CSD码快速转换的电路结构,其速度快、占用资源少.该编码电路用于乘法器中可以减少一半的部分积数目,文中设计了一种16位有/无符号的乘法器,其采用了Wallace加法树和超前进位加法器,整个设计用Verilog HDL语言实现了RTL描述,并在Altera公司的FPGA上进行了实验验证,结果表明该乘法器是可行性的.     

11个冷子管的全加器

图1是一个采用11个冷子管构成的全加器。这个线路总共用了11个冷子管,它的进位传送时间可达到最小。进位传送时间主要决定于从 C_(i-1)到 C_i 位的传输线特性,而不决定于冷子管的开关时间。每一级装配了3个控制进位传送的冷子管,控制时间为开关2个级联冷子管的时间。两数相加所用的时间(不包括进位传送)等于开关一个冷子管的时间。     

子字并行加法器的研究与实现

子字并行加法器能够有效提高多媒体应用程序的处理性能。基于门延迟模型对加法器原理及性能进行了分析,设计了进位截断和进位消除两种子字并行控制机制。在这两种机制的指导下,实现了多种子字并行加法器,并对它们的性能进行了比较和分析。结果表明进位消除机制相对于进位截断机制需要较短的延时,较少的逻辑门数以及较低的功耗。在各种子字并行加法器中,Kogge-Stone加法器具有最少的延迟时间,RCA加法器具有最少的逻辑门数和最低的功耗。研究结果可以用于指导子字并行加法器的设计与选择。     

无进位传送的高速计数器

需要进行超高速计数时,即使有时采用高速线路也很难达到目的,这是由于需要进位传送时间的缘故。下面描述的计数器用一个单独并行计数系统来消除进位的传送。理论现将试验成功的无进位传送的计数方法介绍于下:设寄存器中存有任一个数,首先找出     

一种基于快速比较的分支处理技术

首先分析了分支指令对系统性能的影响,重点描述了超标量流水线微处理器IP核BSR03(Breeze Superscalar RISC 03)中的新型分支处理方法-快速比较的分支处理技术.在快速比较的分支处理技术中把分支的处理融入到译码分派部分,以空间换取时间,使分支的处理得到提前,从而提高系统的性能.     

On time bounds, the work-time scheduling principle, and optimalityfor BSR

Constant time solutions for many applications have been obtained on BSR, but some theoretical problems on BSR (broadcasting with selective reduction) that raised when BSR was proposed have not been solved. Three of them are: 1) No lower bound for any problem on BSR is known except trivial constant time, 2) is there any improvement with nonconstant BSR time but still better than the lower bound for CRCW?, and 3) how to characterize problems for which BSR achieves constant time performance. In this paper, we have solved these three problems. For Problem 1, a lower bound on BSR is shown for any computational problem with an optimal sequential solution. An efficient sorting algorithm answers the second problem. A necessary condition is given for the third problem. The work-time (WT) scheduling principle and optimality for BSR are also introduced for investigating the BSR performance when the number of processors available, p, is different from the input size, n, of problems     

Time-optimal domain-specific querying on enhanced meshes

Query processing is a crucial component of various application domains including information retrieval, database design and management, pattern recognition, robotics, and VLSI. Many of these applications involve data stored in a matrix satisfying a number of properties. One property that occurs time and again specifies that the rows and the columns of the matrix are independently sorted. It is customary to refer to such a matrix as sorted. An instance of the batched searching and ranking problem (BSR) involves a sorted matrix A of items from a totally ordered universe, along with a collection Q of queries. Q is an arbitrary mix of the following query types: for a search query q_j , one is interested in an item of A that is closest to q_j ; for a rank query q_j one is interested in the number of items of A that are strictly smaller than q_j. The BSR problem asks for solving all queries in Q. The authors consider the BSR problem in the following context: the matrix A is pretiled, one item per processor, onto an enhanced mesh of size √n×√n; the m queries are stored, one per processor, in the first m/√n¯ columns of the platform. Their main contribution is twofold. First, they show that any algorithm that solves the BSR problem must take at least Ω(max{logn, √m}) time in the worst case. Second, they show that this time lower bound is tight on meshes of size √n×√n enhanced with multiple broadcasting, by exhibiting an algorithm solving the BSR problem in Θ(max{logn, √m}) time on such a platform     

Random Forest classification model of basal stem rot disease caused by Ganoderma boninense in oil palm plantations

Ganoderma boninense is a fungus that causes basal stem rot (BSR) disease in oil palm plantations. BSR is a major disease in oil palm plantations in both Indonesia and Malaysia. There is no effective treatment for curing BSR; current treatments only prolong the life of oil palms. One strategy to control BSR is early detection of G. boninense infection. Based on the infection symptoms, many researchers have applied remote-sensing techniques for early detection and mapping of BSR disease in oil palms. The main objectives of this article were to evaluate the potential of machine-learning models for predicting BSR disease in oil palm plantations and to produce maps of the distribution of BSR disease. QuickBird imagery archived on 4 August 2008 was applied in three classifier models: Support Vector Machine, Random Forest (RF), and classification and regression tree models The RF model was best at predicting, classifying, and mapping oil palm BSR in terms of overall accuracy (OA), producer accuracy, user accuracy, and kappa value. Using 75% of the data for training and 25% for testing, the RF classifier model achieved 91% OA. In addition, this model separated the healthy and unhealthy oil palms in the study sites into 37,617 (75%) and 12,320 (25%) individuals, respectively.     

仿射运动模型下的图像盲超分辨率重建算法

研究利用帧间存在仿射运动的低分辨率图像序列重建出更高光学分辨率图像的盲超分辨率(BSR)问题。首先给出一种基于特征向量的模糊核零空间矩阵构造方法。将模糊的零子空间约束作为一项规整化泛函,提出一种非参数化模糊辨识、运动估计和图像重建三重耦合问题的联合迭代算法。该算法采用一个二层优化策略:先将三重耦合的BSR问题分解为关于模糊的二次型和关于运动参数与图像的非线性最小二乘(NLS)问题,再采用Gauss-Newton方法求解该NLS问题。仿真实验结果表明,文中提出的仿射变换下的BSR算法能对图像空间移变退化过程进行更为精确的建模,比纯平移BSR算法有更强的局部纹理恢复能力。最后通过真实车牌图像序列展示该算法的适用性。     

Improving source routing reliability in mobile ad hoc networks

In this paper, we propose a novel on-demand routing protocol called backup source routing (BSR) to establish and maintain backup routes that can be utilized after the primary path breaks. The key advantage of BSR is the reduction of the frequency of route discovery flooding, which is recognized as a major overhead in on-demand protocols. We define a new routing metric, called the route reliability, and use it to provide the basis for the backup path selection. We use a heuristic cost function to develop an analytical model and an approximation method to measure this metric. Various algorithms for our BSR protocol in the route discovery phase and route maintenance phase have been designed based on this cost function. Extensive simulations demonstrated that our routing strategy has two interesting features: 1) in less stressful situations of lower mobility, BSR has similar performance to DSR, 2) in more challenging situations of high mobility, BSR can improve the performance significantly.     

An optimal implementation of broadcasting with selective reduction

A model of parallel computation called broadcasting with selective reduction (BSR) can be viewed as a concurrent-read concurrent-write (CRCW) parallel random access machine (PRAM) with one extension. An additional type of concurrent memory access is permitted in BSR, namely the BROADCAST instruction by means of which all N processors may gain access to all M memory locations simultaneously for the purpose of writing. At each memory location, a subset of the incoming broadcast data is selected and reduced to one value finally stored in that location. For several problems, BSR algorithms are known which require fewer steps than the corresponding best-known PRAM algorithms, using the same number of processors. A circuit is introduced to implement the BSR model, and it is shown that, in size and depth, the circuit presented is of the same order as an optimal circuit implementing the PRAM. Thus, if it is reasonable to assume that CRCW PRAM instructions execute in constant time, the assumption of a constant time BROADCAST instruction is no less reasonable     

Restoration of brick and stone relief from single rubbing images

We present a two-level approach for height map estimation from single images, aiming at restoring brick and stone relief(BSR) from their rubbing images in a visually plausible manner. In our approach, the base relief of the low frequency component is estimated automatically with a partial differential equation (PDE)-based mesh deformation scheme. A few vertices near the central area of the object region are selected and assigned with heights estimated by an erosion-based contour map. These vertices together with object boundary vertices, boundary normals as well as the partial differential properties of the mesh are taken as constraints to deform the mesh by minimizing a least-squares error functional. The high frequency detail is estimated directly from rubbing images automatically or optionally with minimal interactive processing. The final height map for a restored BSR is obtained by blending height maps of the base relief and high frequency detail. We demonstrate that our method can not only successfully restore several BSR maps from their rubbing images, but also restore some relief-like surfaces from photographic images.     

A transformation approach to stochastic model reduction

A new and direct approach to stochastic model reduction is developed. The order reduction algorithm is obtained by establishing an equivalence between canonical correlation analysis and solutions to algebraic Riccati equations. Also the concept of balanced stochastic realization (BSR) plays a fundamental role. Asymptotic stability of the reduced-order realization is established, and spectral domain interpretations for the BSR are given.     

Constant time BSR solutions to L1 metric and digital geometry problems

In this paper we solve several geometric and image problems using the BSR (broadcasting with selective reduction) model of parallel computation. All of the solutions presented are constant time algorithms. The computational geometry problems are based on city block distance metrics: all nearest neighbors and furthest pairs ofm points in a plane are computed on a two criteria BSR withm processors, the all nearest foreign neighbors and the all furthest foreign pairs ofm points in the plane problems are solved on three criteria BSR withm processors while the area and perimeter ofm isooriented rectangles are found on a one criterion BSR withm ² processors. The problems on ann ×n binary image which are solved here all use BSR withn ² processors and include: histogramming (one criterion), distance transform (one criterion), medial axis transform (three criteria) and discrete Voronoi diagram of labeled images (two criteria).