Built-in redundancy analysis for memory yield improvement

With the advance of VLSI technology, the capacity and density of memories is rapidly growing. The yield improvement and testing issues have become the most critical challenges for memory manufacturing. Conventionally, redundancies are applied so that the faulty cells can be repairable. Redundancy analysis using external memory testers is becoming inefficient as the chip density continues to grow, especially for the system chip with large embedded memories. This paper presents three redundancy analysis algorithms which can be implemented on-chip. Among them, two are based on the local-bitmap idea: the local repair-most approach is efficient for a general spare architecture, and the local optimization approach has the best repair rate. The essential spare pivoting technique is proposed to reduce the control complexity. Furthermore, a simulator has been developed for evaluating the repair efficiency of different algorithms. It is also used for determining certain important parameters in redundancy design. The redundancy analysis circuit can easily be integrated with the built-in self-test circuit.     

透射电镜电子染色方法的改良

为提高透射电镜生物样品超薄切片的染色效率,在传统染色方法基础上进行改良,使用自制染色装置,在较短时间内完成大批生物样品超薄切片的电子染色。与传统方法相比较省时省药,减少污染机率,电镜观察的超微结构清晰,反差较好。     

Wind Velocity Measurement of Multi-Laser Beams Measurement System Based on Peak Delay Technique

Contactless measurement of wind flow has been utilized in many fields,such as weather forecasting,hurricane tracking,and aeronautic alarm.In this paper,a novel multi-laser beams measuring system(MLBM) for high precision detection of wind field based on optical scintillations and small perturbation theory was proposed and verified.According to the fluctuation intensity of laser backscatter received by two detectors,peak delay technique was adopted to determine the velocity of wind flow.Detailed procedure to ...     

MAC Protocols for Distributed Cooperative Communication Networks

Distributed cooperative networks use the cooperation among nodes to fulfill network resource sharing. However,designing an efficient Media Access Control (MAC) protocol is a key issue for the distributed cooperative network. Based on the principle of MAC-layer cooperation,this paper discusses problems and challenges for MAC protocol design in the distributed cooperative network. Through the analysis of typical cooperative MAC protocols and their performance,this paper concludes that only a reasonable MAC pr...     

基于Metasys系统车间空调机组自动化

为了实现我厂空调系统节能降耗、方便管理、达到工艺要求、提高经济效益等目标,我们选用Johnson Controls(美国江森自控)之Metasys系统对厂区车间的空调进行自控设计。     

集成电路测试系统软件的设计及实现

本文主要展示了集成电路测试系统软件的基本功能及其核心部分的实现方法。先介绍了集成电路测试系统硬件的建模方法,然后在硬件建模的基础上讲述了集成电路软件的结构及设计方法。着重介绍了流程图测试程序转化为文本测试程序的方法以及对文本测试程序的编译方法。用户只需要根据测试流程编写流程图即可以实现测试程序的编写,实现对IC的测试,提高了开发效率。该软件系统具有和硬件系统低耦合性,当向集成电路测试系统添加删改硬件时,不需要修改太多的软件内容即可以正常工作,通用性较好。     

低功耗低误码率的传感器网络节点芯片数字基带设计

本文针对无线传感器网络节点片上系统特点和需求,研究一种低功耗、高性能、低误码率的数字基带(Easibaseband),提出了一种复用加法器和乘法器的设计方法,实现了匹配滤波器,可节省硬件资源并提高系统性能;提出了一种自适应门限的自动增益控制方法,可配合软硬件协同的工作方式,节省接收机的功耗;提出了采用自适应门限的施密特触发器方式进行信号相位判决的方法,降低了解调误码率.本设计在Xilinx的Spartan-3E FPGA上验证并实现,测试结果表明,本收发机的数据传输率可达到111kb/s并支持ISM2.4GHz频段的射频芯片,比传统的并行滤波器节省了5/6的硬件资源,比不采用自动增益控制节省了10.8%的接收机功耗,在信噪比13dB时,误码率在10-4以下,远低于WiseNET的接收误码率.     

低功耗准线性CMOS光电耦合放大器

设计了一款CMOS光电耦合隔离放大器(简称光电耦合放大器),其中输入放大器采用"套筒式"共源一共栅CMOS运放A1,输出放大器选用两级共源一共源CMOS运放A2,A1的输出信号经过两个光电耦合器反馈到输入回路,且A1、A2分别引入负反馈.此外,还采取了其他的改进措施.实验结果表明,与BiCMOS光电耦合放大器相比,所设计的CMOS光电耦舍放大器的±3 dB带宽约增加14 kHz,功耗降低5.46 mW,增益线性度提高到5.9×10-5,因而特别适合于高线性度、低功耗的光电信号处理和智能检测系统中.     

An Ant-Based On-Demand Energy Route Protocol for IEEE 802.15.4 Mesh Network

In this paper, an improved ant-based on-demand energy route (AOER) protocol for IEEE 802.15.4 mesh networks is presented. The information of network status is obtained by Forward_Ant and stored in an inversed pheromone table which simplifies the data structures of route packets. The simplified structure can avoid wasting of storage memories and processing capabilities which are very important for low-power wireless personal area network devices. The average path energy, average network energy and minimum remaining node energy of the path are combined to evaluate paths and update the inversed pheromone table. The positive and negative reinforcement of ant colony optimization algorithm are used to enhance the routes with better fitness. The pseudo-random-proportional-selection strategy is used to determine routes with the transferring of Backward_Ant from the destination to the source. Nodes with higher pheromone trail values are selected as the next hop with higher probabilities, therefore the network loads are distributed and nodes energy consumptions are balanced. A proactive route maintenance mechanism is also used in AOER to trigger route maintenance and avoid over-use of node energy. Experimental results on NS-2 show that AOER performs better than AODVjr in different network traffics and dynamics.     

CNT-FED背光源中支撑体高度的优化研究

利用丝网印刷技术制备碳纳米管阴极并真空封装碳纳米管场发射(CNT-FED)背光源原型器件,研究了支撑体高度对碳纳米管背光源发射性能的影响,实验表明:支撑体高度增加,开启电压随之增加;达到同样的发射电流密度,支撑体越高,亮度也越高.支撑体高度为1 000 μm和2 000μm时,CNT-FED背光源发射性能较好,在电流密度为4 mA/cm~2情况下,支撑体高度为1 OOO μm时,亮度为1 800 cd/m~2;支撑体高度为2 OOO μm时,亮度为3 100 cd/m~2.选用支撑体高度为2 000 μm,制备出86.4 cm液晶平板显示器(LCD)用CNT-FED背光源,亮度最高可达8 000cd/m~2,发光均匀性为82%,稳定发射30 h,发射电流无明显衰减.