An Efficient Systolic Algorithm for the Longest Common Subsequence Problem

A longest common subsequence (LCS) of two strings is a common subsequence of the two strings of maximal length. The LCS problem is to find an LCS of two given strings and the length of the LCS (LLCS). In this paper, a fast linear systolic algorithm that improves on previous systolic algorithms for solving the LCS problem is presented. For two given strings of length m and n, where m n, the LLCS and an LCS can be found in m + 2n – 1 time steps. This algorithm achieves the tight lower bound of the time complexity under the situation where symbols are input sequentially to a linear array of n processors. The systolic algorithm can be modified to take only m + n steps on multicomputers by using the scatter operation.     

二维任意形状寄生电阻电容的边界元计算

由于集成电路技术高速发展,精确提取任意形状寄生电阻电容变得十分重要,本文以直接边界元素法为基础,利用圆弧样条插值近似任意曲线边界,使插值曲线具有整体一阶连续性,并克服了大挠度与多值的困扰。在直线边界使用线性连续元,在曲线边界使用二次连续无。对两邻国为直线的角点,我们曾提出处理角点处存在多重法的导数的一种方法。这里,它被推广到角点邻边含曲线段的情形。数值结果表明模拟器是可行的。     

A fully differential transimpedance amplifier with integrated differential photodetector in standard CMOS process for optical communications and interconnects

A fully differential transimpedance amplifier (TIA) with integrated differential photodetector in standard CMOS technologies has been realized for optical receivers in optical communications and optical interconnects. And a novel, fully differential photodetector aiming to convert the incident light into a pair of fully differential photo-generated currents and ensure the differential symmetry on circuit configuration and model has also been proposed for the differential TIA to achieve the fully differentia...     

Enhancing encoding capacity of combinational test stimulus decompressors

While scan-based compression is widely utilized in order to alleviate the test time and data volume problems,the overall compression level is dictated not only by the chain to channel ratio but also the ratio of encodable patterns.Aggressively increasing the number of scan chains in an effort to raise the compression levels may reduce the ratio of encodable patterns,degrading the overall compression level.In this paper,we present various methods to improve the ratio of encodable patterns.These methods are b...     

A fully integrated 1‐in. AMOLED display using current feedback based on a five‐mask LTPS CMOS process

Abstract— In the past, a five‐mask LTPS CMOS process requiring only one single ion‐doping step was used. Based on that process, all necessary components for the realization of a fully integrated AMOLED display using a 3T1C current‐feedback pixel circuit has recently been developed. The integrated data driver is based on a newly developed LTPS operational amplifier, which does not require any compensation for Vth or mobility variations. Only one operational amplifier per column is used to perform digital‐to‐analog conversion as well as current control. In order to achieve high‐precision analog behavior, the operational amplifier is embedded in a switched capacitor network. In addition to circuit verification by simulation and analytic analysis, a 1‐in. fully integrated AMOLED demonstrator was successfully built. To the best of the authors' knowledge, this is the first implementation of a fully integrated AMOLED display with current feedback.     

A comparative study of two techniques for improving power‐handling capability of CMOS T/R switches

This article proposes an asymmetric topology for transmit/receive (T/R) switches and more importantly presents a comparative study of both LC‐tuned and resistive body‐floating techniques for improving the power‐handling capability of the T/R switches in the same 0.18‐μm triple‐well CMOS. It is shown from simulations and measurements that the switches adopting either technique achieve comparable performances. For instance, the switch employing the LC‐tuned body‐floating technique exhibits insertion loss of 1.5 dB, isolation of 23.5 dB, and power‐handling capability of 22.5 dBm at 5.2 GHz, whereas the switch using the resistive body‐floating technique exhibits insertion loss of 1.3 dB, isolation of 24 dB, and power‐handling capability of 22.2 dBm, respectively. Therefore, one can conclude that the asymmetric topology with the resistive body‐floating technique is more suitable for designing T/R switches for wireless local area network applications as it consumes smaller silicon area. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010.     

Combining temporal partitioning and temporal placement techniques for communication cost improvement

In this paper, we present a typical temporal partitioning methodology that temporally partitions a data flow graph on reconfigurable system. Our approach optimizes the communication cost of the design. This aim can be reached by minimizing the transfer of data required between design partitions and the routing cost between FPGA modules. Consequently, our algorithm is composed by two main steps. The first step aims to find a temporal partitioning of the graph. This step gives the optimal solution in term of communication cost. Next, our approach builds the best architecture, on a partially reconfigurable FPGA, that gives the lowest routing cost between modules. The proposed methodology was tested on several examples on the Xilinx Virtex-II pro. The results show significant reduction in the communication cost compared with others famous approaches used in this field.     

高速可配置RS纠删解码器的VLSI设计

目前对可配置纠错与删除(纠删)解码器研究较少。为此,采用性能优异的RS编码方法,提出一种高速可配置RS纠删解码器的超大规模集成电路(VLSI)架构,并详述可配置纠删BM模块的构成。该架构通过折叠技术,使解码器在保证高速的前提下降低硬件复杂度。通过0.18 μm工艺和Design Complier工具综合测试结果表明,与同类解码器研究相比,该解码器在硬件复杂度吞吐率和可配置性方面,均具有较大优势。     

A CMOS optical detection system for point-of-use luminescent oxygen sensing

This work describes a stable and sensitive optical oxygen sensor based on a consumer CMOS image sensor array and polarization signal isolation. The consumer CMOS image sensor is inherently color discriminating, while the polarization is a wavelength-independent scheme for filtering excitation light. Combination of these two components generates a compact, multi-color detection system applicable to luminescence-based sensing. The optical system is applied to point-of-use oxygen sensing based on quenching of platinum octaethylporphine (PtOEP) luminophore. Sensitivity of the demonstrated portable oxygen sensor is comparable to that of benchtop spectroscopy-based systems. Taking advantage of the spatial resolution of the CMOS image sensor, an oxygen insensitive reference can be integrated to improve the reliability when powered by a battery. The low-cost and high sensitivity of the demonstrated optical sensing approach make it promising for point-of-use applications.     

应用于开关电源的CMOS电流控制振荡器

提出了一种结构简单的CMOS电流控制模式振荡器。该电路利用系统内部参考电压和外接电阻产生的电流信号对电容进行充放电,通过调节外接电阻大小,振荡器输出频率在660 kHz～4.15 MHz内可调。