A case history development of a foolproofing interfacedocumentation system

The authors discuss information transmission errors occurring between design engineers involved in software development and describe an interface design documentation system that can prevent them. The equivalence of human errors in software design and hardware manufacturing activities is established. The characteristics that must be included in an interface documentation system to prevent communication errors in software design activities, based on foolproofing principles that were identified for hardware manufacturing, are discussed. Utilizing these characteristics, an example of an interface documentation system for software products which control measuring equipment is presented. Its effects on the resultant number of communication errors between hardware and software engineers is subsequently experimentally evaluated     

嵌入式系统协同验证环境的设计与实现

介绍了一个用来验证嵌入式系统硬件／软件,及其交互功能的硬件／软件协同验证环境,硬件／软件功能分别使用系统提供的ＥＨＤＬ语言及ＥＳＤＬ语言设计和描述,该协同验证环境由嵌入式软件调试器和嵌入式硬件模拟器组成,其采用了指令集结构的协同模拟模型,利用该集成环境,硬件／软件的设计错误可以在系统制造之前被发现并修改。     

嵌入式系统虚拟开发环境的设计与实现

在嵌入式系统虚拟开发环境中为软件与硬件分别设计了ＥＳＤＬ语言和ＥＨＤＬ语言．ＥＳＤＬ是ＡＮＳＩＣ的超集,它为嵌入式编程增加了一些数据类型．ＥＨＤＬ是一种硬件描述语言．开发人员可以利用由嵌入式软件调度器和嵌入式硬件模拟器组成的协同验证环境调试嵌入式系统．利用这个虚拟的集成环境,软件开发人员可以在设计初期发现与硬件相关的错误,硬件开发人员可以获得系统功能的真实描述．硬件、软件的设计错误可以在系统制造之     

基于VSl003解码器的MP3播放器设计

以MSP430F149作为核心控制器,结合VSl003音频解码器,设计了一种带SD卡的MP3播放器,给出了MP3播放系统的软硬件设计。在硬件设计上,解码器与存储器分离,增加了存储容量;在软件设计上,使用条项菜单方式进行管理,可以方便地进行硬件或软件的升级。经过测试,该MP3播放器播放效果较好。     

Hardware/software trade-offs for bitmap graphics on the blit

The Blit is an experimental bitmap graphics terminal built for research into interactive computer graphics on the UNIX time-sharing system. The hardware is inexpensive and the graphics functions are implemented entirely in software. Nevertheless, the graphics performance of the Blit is comparable or superior to some displays with special-purpose graphics hardware. This paper explains the paradox by referring to some principles of design: the hardware and software should be designed together to complement each other; carefully designed software can outperform infelicitous hardware; and simplicity of design leads to efficiency of execution. These principles are illustrated by examples from the Blit hardware and software and comparisons with other systems.     

嵌入式系统软硬件协同验证中软件验证方法

随着集成电路及计算机技术的发展,嵌入式系统设计变得越来越复杂．复杂的嵌入式系统设计,通常采用验证的手段检验系统设计的正确性,硬件验证通常是在硬件设计描述的基础上建立用于模拟硬件功能的硬件模拟器;软件验证常用的方法是建立处理器功能模型(指令集模拟器ISS),逐条解释嵌入式软件在目标机器上的执行过程,产生模拟输出,驱动外围电路(即硬件设计)．指令集模拟器从底层时序关系模拟嵌入式软件在目标CPU上运行过程．对于复杂嵌入式系统设计,ISS模拟速度通常成为协同模拟瓶颈．基于RTOS的嵌入式软件快速验证方法可以有效地提高软件模拟速度,扩展RTOS功能,适应协同模拟需要,建立硬件模拟驱动,实现软件和硬件模拟器通信连接和协同模拟同步控制．基于RTOS的嵌入式软件验证方法以编译代码模型为基础,从系统行为级验证嵌入式软件功能,验证速度快．在实际应用中,该方法和ISS验证相结合,能够实现更有效、更快速的嵌入式系统协同验证．最后以几个典型硬件设计为基础,编写相应的控制软件,进行软硬件协同验证实验,实验结果数据说明该验证方法实用、有效、快速．     

基于Python的sigmoid函数FPGA实现

sigmoid函数是人工神经网络中通常采用的传递函数,采用基于Python的软硬件协同设计方法,在FPGA上实现了定点sigmoid函数。实验结果表明采用基于Python的软硬件协同设计方法,可以利用Python上大量的包和模块从而大幅度提高系统设计、仿真和校验的效率,并且能将软件算法快速有效地转换为硬件实现,在整个软硬件设计过程中仅采用Python语言,解决了当前系统设计中软硬件设计者分别采用不同设计语言存在的沟通问题。     

An Integrated Hardware/Software Data Prefetching Scheme for Shared-Memory Multiprocessors1

Both hardware and software prefetching have been shown to be effective in tolerating the large memory latencies inherent in shared-memory multiprocessors; however, both types of prefetching have their shortcomings. While software schemes require less hardware support than hardware schemes, they must generate address calculation instructions and a prefetch instruction for each datum that needs to be prefetched. Hardware schemes, however, must become progressively more complex to be able to compute data access strides and to increase the prefetching lookahead. In this paper, we propose an integrated hardware/software prefetching method that uses simple hardware that can handle most data accesses and software prefetching for the few remaining accesses. A compile time algorithm analyzes the access streams formed by array references and determines sequences of consecutive memory accesses to an access stream that can be prefetched by the hardware mechanism. This analysis is based on the relative memory locations of consecutive accesses to an access stream and the number of intervening data references between consecutive accesses to an access stream. In addition, the prefetching lookahead can be set separately for each access stream. Our approach yields an effective scheme that minimizes both CPU overhead and hardware costs. Execution-driven simulations show our method to be very effective.     

基于Petri网的软硬件故障建模方法研究

针对计算机系统中软件和硬件相互作用而引发的故障分析问题,提出了基于Petri网的软硬件故障模型,用以表达软件故障和硬件故障相互作用的复杂过程,在此基础上给出了软件、硬件和软硬件故障模式的形式化定义。根据软硬件故障模式的特征,基于故障的传播过程提出了软硬件故障识别算法。实例结果表明模型和算法可以准确的分析和识别软硬件故障,从而为计算机系统的可靠性分析提供了新的途径。     

基于SOPC的液晶屏接口组件设计

本文介绍基于SOPC的液晶屏接口组件的设计方法。利用SOPCBuilder中的组件编辑器(ComponentEditor)实现液晶屏接口设计。文中系统介绍组件的硬件和软件的设计方法,该方法可将硬件抽象为软件,让开发者不必了解硬件结构就可以使用硬件,以标准C语言函数来操作组件,使用方便,具有灵活性、高效性和低成本的特点。     

On interfaces

The nature of interfaces is discussed. It is recommended that modern software approaches to interfaces (such as abstract data types) be extended to interfaces of all kinds. These interfaces can and should be developed at the level of abstraction appropriate to the interacting elements, rather than at the level of their lowest common denominator, which is frequently the case. It is proposed that for an interface to exist at any level of abstraction, there must be an operational framework that implements that level of abstraction and within which the interfacing elements interact. Four tasks required for the development of interfaces are described. The traditional classification of interfaces as hardware/software, software/software, and hardware/hardware is found wanting and a new partitioning is suggested—structural or interpretive interfaces, symbolic interfaces, and physical interfaces. Standards and scientific and engineering theories are shown to define levels of abstraction for general interfaces in much the same way that programming languages do for software interfaces. Implications for software engineering and concurrent engineering are explored.     

一个嵌入式Internet软件开发平台的研究与实现

设计并实现了，一个嵌入式Internet软件开发平台ElBuider该平台提供了一个包含实时内核和相关系统组件的嵌入式Internet架构,设计了相应的CGl程序库和JavaApplet类库，EIBuilddr使用户将业务逻辑集中在软件开发及测试上，主要的软件问题能在软／硬件集成之前被斛决，有效降低了软件开发难度，提高了开发效率。     

基于AT89S52单片机的热电偶无线测温装置设计

实现了基于k型热电偶的无线测温系统,并满足应用场合的技术指标,包括硬件电路设计、采样数据的存储、USB接口的设计和上位机软件的设计。在具体的设计中,根据测温系统的性能指标要求,列硬件和软件功能做了合理的分配。实验结果表明：软硬件平台运行稳定,系统整体功能能够实现。     

Risk Assessment of Computer Controlled Systems

Software is increasingly being used to control and monitor systems for which safety and reliability are critical. When comparing software designs for such systems, an evaluation of how each design can contribute to the risk of system failure is desirable. Unfortunately, the science of risk assessment of combined hardware and software systems is in its infancy. Risk assessment of combined hardware/software systems is often based on oversimplified assumptions about software behavior.     

Fault injection techniques and tools

Fault injection is important to evaluating the dependability of computer systems. Researchers and engineers have created many novel methods to inject faults, which can be implemented in both hardware and software. The contrast between the hardware and software methods lies mainly in the fault injection points they can access, the cost and the level of perturbation. Hardware methods can inject faults into chip pins and internal components, such as combinational circuits and registers that are not software-addressable. On the other hand, software methods are convenient for directly producing changes at the software-state level. Thus, we use hardware methods to evaluate low-level error detection and masking mechanisms, and software methods to test higher level mechanisms. Software methods are less expensive, but they also incur a higher perturbation overhead because they execute software on the target system     

基于DPI的流量识别系统的研究

随着网络应用的多样化,各种网络流量不断复杂化、多样化,各种网络安全事故频发.网络流量的分布不均匀以及网络安全状况的复杂使得互联网急需管理和维护,网络流量的监控问题变得尤为重要.流量识别作为一种能够自动、实时保障网络监控的技术,成为防火墙一类静态安全设备的必要补充,越来越受到人们的重视.深度包监测（DPI）技术以其识别的准确性成为应用越来越广泛的识别技术.然而单纯的软件实现系统监测速度较慢,不能满足网络高速数据包处理的吞吐量要求.单纯的硬件识别知识库会占用大量内存,一般的硬件内存达不到要求.单纯的软件识别效率又不能满足越来越大的网络吞吐量需求.这种情况下,文章研究了一种基于正则表达式的软硬件结合系统实现方法,该方法的主要思想是硬件识别网络常见协议,软件识别复杂的网络协议,且两者都支持正则表达式.这种方法兼具软件与硬件实现的优点,与传统的软件实现相比,在识别效率方面有明显提高.     

FPGA的验证平台及有效的SoC验证方法

设计了一种基于FPGA的验证平台及有效的SoC验证方法,介绍了此FPGA验证软硬件平台及软硬件协同验证架构,讨论和分析了利用FPGA软硬件协同系统验证SoC系统的过程和方法.利用此软硬件协同验证技术方法,验证了SoC系统、DSP指令、硬件IP等.实验证明,此FPGA验证平台能够验证SoC设计,提高了设计效率.     

Programming by contract

Why can't software be more like hardware? has been the software engineer's lament for nearly as long as there have been large software systems. In particular, why isn't there a software components industry to rival the existing hardware components industry? Hardware components come with the following attributes: an interface that hides detail that would only confuse or at least distract me; an unambiguous interface specification written in a language I can understand (in the case of the integrated circuit, this may be a fairly complex language, but it's one I expect to learn if I'm going to work with that hardware); a guarantee-the component has been tested and/or validated against its specification. All three items-especially the last one-are notably lacking for software components. Indeed, software tends to come with an antiguarantee, otherwise known as a disclaimer. All of the above points rely on a rigorous specification of the hardware component's interface. In a nutshell, programming by contract is about providing just such specifications for software components (that is, classes), and it provides the best hope of a basis for a true software component industry. The discussion focuses on object oriented software     

虚拟仪器系统误差的软件消除算法

为了提高测量精度,设计并实现了虚拟仪器系统误差的软件消除算法。以LabVIEW为开发软件,PCI输入/输出卡为信号采集和输出控制构建虚拟仪器系统;根据组成将误差分为：软件误差和硬件误差。软件误差来源于开发软件,消除方法具有多样性;硬件误差消除算法：采集一定量的数据值并按大小排序,删除序列中较大和较小的数据值,将剩下的数据值求平均得平均值,再将它加上表头检定值即为测试值。实验结果表明,算法能有效消除误差。     

A survey of cache coherence schemes for multiprocessors

Schemes for cache coherence that exhibit various degrees of hardware complexity, ranging from protocols that maintain coherence in hardware, to software policies that prevent the existence of copies of shared, writable data, are surveyed. Some examples of the use of shared data are examined. These examples help point out a number of performance issues. Hardware protocols are considered. It is seen that consistency can be maintained efficiently, although in some cases with considerable hardware complexity, especially for multiprocessors with many processors. Software schemes are investigated as an alternative capable of reducing the hardware cost