42V电气系统在汽车中的应用研究

对汽车电气系统的发展趋势进行了分析,介绍了42V电气系统的分类及其对能量存储系统的要求,给出了42V电气系统结构的四种可能方案并对其差异进行了简略分析,最后介绍了42V电气系统的核心装置一体化动发电机系统及其研发现状.     

基带通信中常见噪声的产生方法研究

通常的实验环境中,对数字基带信号的研究是要加入一定的模拟噪声来测量各种参数的。实际中的噪声多种多样,有最简单的均匀白噪声,高斯白噪声,突发随机脉冲噪声以及其他各种分布的随机噪声。通过吸纳或改进传统的产生方法,本文从理论和工程上都给出了产生这些类型噪声的方法,并进一步结合ISA总线设计了基于双RAM的噪声动态产生系统     

Single-Cycle Bit Permutations with MOMR Execution

Secure computing paradigms impose new architectural challenges for general-purpose processors. Cryptographic processing is needed for secure communications, storage, and computations. We identify two categories of operations in symmetric-key and public-key cryptographic algorithms that are not common in previous general-purpose workloads： advanced bit operations within a word and multi-word operations. We define MOMR （Multiple Operands Multiple Results） execution or datarich execution as a unified solution to both challenges. It allows arbitrary n-bit permutations to be achieved in one or two cycles, rather than O（n） cycles as in existing RISC processors. It also enables significant acceleration of multiword multiplications needed by public-key ciphers. We propose two implementations of MOMR： one employs only hardware changes while the other uses Instruction Set Architecture （ISA） support. We show that MOMR execution leverages available resources in typical multi-issue processors with minimal additional cost. Multi-issue processors enhanced with MOMR units provide additional speedup over standard multi-issue processors with the same datapath. MOMR is a general architectural solution for word-oriented processor architectures to incorporate datarich operations.     

高速数据采集系统的设计

本文介绍了一种包括数据采集硬件及数据处理软件的高速数据采集系统。硬件部分为高速单片机DSC875 2 0控制的高速数据采集卡 ,通过ISA总线与工控机连结 ,主要采用了ISA总线技术、I/O接口技术和中断技术。用DELPHI语言编写的软件系统对数据进行分析和处理。本系统的特点在于该系统在单片机的控制下实现高速数据采集 ,采样频率可达 1～ 2MHz。该系统可靠性高 ,抗干扰能力强 ,造价低廉     

A multiple access protocol with explicit and implicit reservation

A new version of a MAC‐level protocol is introduced and investigated, operating in a cellular environment, where a base station co‐ordinates mobile users within each cell. The channel multiplexing structure is based on time division, and the slots in each frame are dynamically assigned to the users and their service classes by the cell base station. Decisions are taken on the basis of binary channel feedback information (collision/no collision), by assuming independence in the presence of packets at the mobile stations, and aim at maximizing the one‐step throughput in the current frame. The frame is divided into two periods: the first (short) one contains a number of minislots, equal to the number of ‘real’ slots (i.e. those capable of containing a fixed size packet) of the second part. At the beginning of the frame, the access rights are computed and broadcast to the users; the enabled stations that have a packet to transmit respond, by sending a short burst that contains their ID in a minislot. This most recent feedback is used at the base station to update the parameters of the decision algorithm, which is then re‐applied to yield the final access rights for the second part of the frame. The performance of the scheme is analysed by simulation in the presence of mixed voice and data traffic, and compared with those of a reservation random access protocol using the same algorithm in a single‐phase fashion (RRA‐ISA) and PRMA. Copyright © 2001 John Wiley & Sons, Ltd.     

ISA板卡的即插即用技术

本文介绍了即插即用BIOS识别和配置ISA板卡的一般过程,并对ISA即插即用规范中的初始化和隔离算法等内容进行了详细讨论.     

基于PC机的果菜保鲜库温度巡回检测系统的研制

为使水果和蔬菜保鲜库冷藏库内的温度保持在要求范围内，采用微机对库温进行多路动态巡回检测有重要意义，文章介绍一个微机多路温度自动监测系统的工作原理、硬件构成及软件设计。该系统已投入使用，运行稳定，达到了预期设计要求。     

基于柔度法的裂纹扩展动态数据采集系统的研究

在柔度法测量裂纹扩展系统研究中根据要求，以PC机为核心，为其设计了专用的数据采集卡，采集实验数据达到了满意的效果。文中较为详细的介绍了利用AD7874模数转换器，在ISA接口规范的基础上，设计该采集系统的过程及整个系统的工作情况。     

一种灵活的信道特性仿真ISA卡实现

一种灵活多样的信道特性仿真系统，在通信平台的研制与测试中，是非常必需的。本文详细地介绍了一种灵活的信道特性仿真ISA卡的原理与实现，并就误码产生系统给出了程序流图。