Programming real-time applications with SIGNAL

The authors present the main features of the SIGNAL language and its compiler. Designed to provide safe real time system programming, the SIGNAL language is based on synchronous principles. Its semantics are defined via a mathematical model of multiple-clocked flows of data and events. SIGNAL programs describe relations on such objects, so that it is possible to program a real time application via constraints. The compiler calculates the solutions of the system and thus can be used as a proof system. The equational approach is a natural way to derive multiprocessor executions of a program. This approach uses a graphical interface of a block-diagram style, and the system is illustrated on a speech recognition application     

Specification and Validation of Embedded Systems using LUSTRE and ARGOS. Case Study: The Automatic Headlight Leveling System

In thisarticle, the design, modeling and validation of embedded systemsis examined. There exist commercial tools for the developmentof control- or data-flow dominated systems, e.g.STATEMATE for control dominated systems and MATLAB for data-flowdominated systems, but there are problems to describe mixed systems.The system is split in a control and a transformation part. Thecontrol part is described with the graphical language ARGOS,the transformation part with the data-flow language LUSTRE. Integrationis done based on their common synchronous architecture. The designprocess is shown in a case study on an industrial application,the automatic headlight leveling system. A validation strategyaccording to the separation of the system is shown. Safety propertiesof the control part are proved with model checking, functionalcorrectness is shown in two steps by simulation and hardwarein the loop simulation.     

Extended Synchronous Dataflow for Efficient DSP System Prototyping

Though synchronous dataflow (SDF) graph has been a successful input specification language for digital signal processing (DSP) applications, lack of support for global states makes it unsuitable for multimedia signal processing applications that need global states for efficient implementation. In this paper, we propose synchronous piggybacked dataflow (SPDF), an extension of SDF model to accommodate global states without side effects. Global states are accessed by a special block that piggybacks the global state update request on data samples. Such an extension enlarges the domain of application where dataflow representation can be used for rapid system prototyping. The only penalty it incurs is scheduling complexity since the scheduler now considers control dependency as well as data dependency. We present the static analysis of the SPDF model and an implementation technique for memory efficient code synthesis. Finally, we show experimental results with a real life example, MPEG-audio decoder, to present the novelty and usefulness of our approach.     

城市电视台非线性网络编辑及硬盘播出系统的研究

社会地不断发展,使得很多新的科学技术层出不穷,网络技术改变了很多领域的发展方式,对于城市电视台来说,网络技术的出现给城市电台的发展带来了机遇,使得视频的剪辑更加方便,并且有利于电视台节目的编辑与制作。同时,数字电视的发展给城市电视台的非线性网络编辑提供了更加便利的条件,使得电视台可以集节目的采访、制作、播出为一体,提高了电视台职工的工作效率,但是在具体的发展过程中,电视台的节目播出与制作技术还有待提升,因此应该对于电视台的非线性网络编辑以及硬盘播出系统进行深入的研究。     

采用CY7C68013A的USB系统固件程序设计

在USB系统设计的过程中，编写固件程序是非常重要的一个环节，它直接影响到开发产品的数据传输速度。文章以CYPRESS公司的USB外设接口芯片FX2为例，介绍了在设计开发USB外设中，固件的作用以及固件程序的编写流程，并给出了相应的VHDL语言程序。     

A new driving scheme for synchronous rectifiers: single windingself-driven synchronous rectification

Single winding self-driven synchronous rectification (SWSDSR) approach is a new driving circuit that overcomes the limitations of the traditional driving schemes, becoming an interesting alternative to supply new electronic loads such as microprocessors. Traditional self-driven synchronous rectification (SDSR) technique has shown very good performance to improve efficiency and thermal management in low-voltage low-power DC/DC converters, however it can not be extended to the new fast dynamic, very low voltage applications. SWSDSR scheme is based on an additional winding in the power transformer (auxiliary winding). It allows for maintaining the synchronous rectifiers (SRs,) on even when the voltage in the transformer is zero, which is impossible to do in traditional self-driven approaches. It also makes it possible to drive properly the SRs even in very low voltage applications, 1.5 V or less. Coupling of the windings strongly affects the performance of the SWSDSR technique. The influence of the coupling between the different windings is analyzed through simulations of different transformers designed for the same application. Models of transformers are generated with a finite element analysis (FEA) tool. Goodness of the SWSDSR scheme is validated through experimental results     

Automated chemistry laboratory: Application of a novel time-shared computer system

A promising strategy for providing a hospital information system is the gradual development and subsequent integration of well-defined information processing modules. A computer system which is suitable and economical to serve one or more of these modules has been developed. Its unique feature is that it uses an interpretive language for all the application programs both in the developmental and service modes of operation. The interpretive language, which has been designed specifically for data management applications, facilitates the creation and debugging of programs; in addition, it allows the time-sharing of a relatively small computer with a negligible overhead for switching control from one program to the next. The multiterminal, real-time remote-access computer system has been in service operation at the Clinical Chemistry Laboratory of the Massachusetts General Hospital since the early Fall of 1968. Presently, the system accepts typed-in requisition information, creates patient files, and generates schedules for centrifuging blood samples and for the performing of all tests; the system also accepts test results and provides reports on individual patients. In the near future all test results will be manually entered into the machine, which will then generate cumulative test reports each day. The on-line connection of automated laboratory equipment (AutoAnalyzers) will soon follow. Analysis of the system performance shows that the use of an interpretive language is suitable for this application, and it also indicates that the system has sufficient capacity for serving additional information processing needs.     

凌阳16位单片机与上位机串行通信实现

基于单片机SPCE061A与PC机进行数据交换而设计了一个串行通信系统,通信方式采用异步串行通信方式。给出了SPCE061A与PC机两者间串行通信时的电平转换的分析说明和串行通信程序设计。通信协议部分给出了通信数据格式和波特率设置,程序设计的关键问题中具体介绍了中断控制单元的设置,最后给出通用异步串行口发送中断程序的设计流程和数据发送接收的部分程序。单片机程序采用汇编语言编写,上位机程序采用VB 6.0语言编写。该串行通信系统已经调试成功并运行良好。     

基于数据流的软件测试序列自动生成技术研究

测试用例自动生成技术是软件测试的一个重要研究领域，而如何从待测试程序中选取适当的测试序列集合是其中的一个关键问题。文章提出一种构造结构性测试序列集合的方法，此方法首先对待测试程序进行静态分析，然后根据程序的语句间关系生成程序图，最后基于数据流测试准则，根据程序图以及变量的定义和使用信息构造结构性测试序列集合。在Linux平台上使用这种方法对若干条程序进行分析处理，得到的测试序列集合可以使待测试程序得到充分测试。本文提出的方法具有比较高的测试覆盖，同时，在计算过程中避免了无用路径的生成，节省了算法空间和执行时间。     

Packet processing and data plane program verification: A survey with tools,techniques, and challenges

In today's era of fast-growing network-enabled devices combined, it increases the complexity of the network. This leads to the massive data packet transfer on the network via the data plane in a software-defined networking environment. The programmable packet processing in a data plane may introduce indirect bugs that are hard to catch manually. To avoid catastrophic after-effects, such programs need to be formally verified. Researchers have proposed various tools and techniques to verify the data plane program using the P4 language. Most of the researchers have used the concept of assertion and symbolic execution to provide P4 verification approaches. As symbolic execution does not scale up well, researchers have proposed different techniques, which include the use of constraints, slicing of the program, parallelization, data plane verification, program verification, and so on. The tools have experimented with different choices for compiler optimization. In this article, we perform a pervasive survey on various verification tools and techniques based on data plane programming using domain-specific language like P4 from the inception of the concept. We have compared the packet processing tools developed as per the requirement of time with their ideology and the impact of change.     

Microprogramming—Another look at internal computer control

The internal control of a computer is directed by the instruction. The instruction causes a sequence of steps (or microinstructions) to occur which interpret the instruction. This interpretation of an instruction can be implemented by a storage media called a control store. The programs written for this media are called microprograms. The recent availability of fast READ-WRITE bipolar storage media now makes possible the rapid changing of content of this storage and hence makes possible computer organizations which can interpret a wide variety of different types of instructions. These computer organizatios are called soft machine architectures. It is also possible to conceive of new "machine languages" or directly executable languages which are specially developed as an intermediate level between a specific higher level language and the microprogrammable machine.     

A High-Level Approach to Analyze the Effects of Soft Errors on Lossless Compression Algorithms

In space applications, the data logging sub-system often requires compression to cope with large amounts of data as well as with limited storage and communication capabilities. The usage of Commercial off-the-Shelf (COTS) hardware components is becoming more common, since they are particularly suitable to meet high performance requirements and also to cut the cost with respect to space qualified ones. On the other side, given the characteristics of the space environment, the usage of COTS components makes radiation-induced soft errors highly probable. The purpose of this work is to analyze a set of lossless compression algorithms in order to compare their robustness against soft errors. The proposed approach works on the unhardened version of the programs, aiming to estimate their intrinsic robustness. The main contribution of the work lies in the investigation of the possibility of performing an early comparison between different compression algorithms at a high level, by only considering their data structures (corresponding to program variables). This approach is virtually agnostic of the downstream implementation details. This means that the proposed approach aims to perform a comparison (in terms of robustness against soft errors) between the considered programs before the final computing platform is defined. The results of the high-level analysis can also be used to collect useful information to optimize the hardening phase. Experimental results based on the OpenRISC processor are reported. They suggest that when properly adopted, the proposed approach makes it possible to perform a comparison between a set of compression algorithms, even with a very limited knowledge of the target computing system.     

An integrated services token-controlled ring network

A ring protocol is proposed that allows voice and data traffic to coexist within the ring. This ring has the following distinct features: (1) it allows synchronous traffic such as voice and video to have a definite access to the channel within each packetization period (or frame); (2) it allows data messages to have a higher channel access priority provided that the synchronous traffic is not delayed by more than one frame; (3) it supports variable rate data circuits. Simulation results show that the data-message delay is much smaller than for other integrated services schemes. Urgent messages can be transmitted with a higher priority over voice. Since the voice packet delay is bounded within one packetization period, no time-stamping is needed and the voice loss can be completely avoided by reserving a sufficient number of slots. Continual speech reception is possible by synchronizing the speech regeneration process to the end of each frame. Since the ring is synchronized, gateway switching to external circuit-switched and packet-switched networks is very simple     

VHDL元件的Simulink／Modelsim功能测试方法

由于VHDL语言注重硬件行为描述,VHDL程序的测试方法与传统高级设计语言程序和汇编语言程序的测试方法不同。VHDL程序测试向量的自动生成方法和覆盖率测试是其功能测试中的难点。基于Matlab／Simulink的方法,将VHDL程序作为整个模型系统中的一个元件来考察,就其硬件环境进行建模,和Modelsim进行协同仿真。该方法简化了测试流程,无需采用复杂的testbench编写方法,提高了测试的完整性。     

ANEMONA: a programming language for network monitoring applications

This work presents ANEMONA: A language for programming NEtwork MONitoring Applications. The compilation of an ANEMONA program generates code for configuring a policy repository and the corresponding policy deployment and event monitoring. The language allows the definition of expressions of managed objects that are monitored, as well as triggers that when fired may indicate the occurrence of associated events, which are also defined by the language. A translator for the language was implemented that generates code for configuring both the policy repository and deployment. The current implementation of the language employs the Expression MIB and Event MIB. Experimental results are presented, including an ANEMONA program that detects TCP Syn Flooding attacks, and a program for detecting steep variations in the utilization of monitored links. Copyright © 2007 John Wiley & Sons, Ltd.     

基于Windows平台的自动化设备软件发布方法

介绍了一种基于Windows操作系统的自动化测试设备软件的发布方法,用Visual C＋＋开发了配置ODBC（开放的数据库互连）数据源和卸载ODBC数据源的程序。EasySetup是一种制作安装程序的工具软件,高效易用。用它制作的安装程序在安装开始前、安装完成后或卸载前可以自动执行相关文件（．bat、．exe、．reg）并进行授权管理、修改注册表或配置ODBC数据源等工作。     

TD-LTE终端协议一致性测试自主开发测试例的设计与实现

基于TICN语言的一致性测试原理和测试方法,针对TD-LTE终端协议一致性测试系统中无法实现个性化流程测试的问题,提出用户自主开发测试倒的方案。介绍了。TD-LTE终端一致性测试系统的软件结构。在此基础上重点研究了基于IBMRational Systems Tester、其他1rrCN工具、非TYCN语言和GUI的四种开发方案。通过仿真平台测试表明,个性化流程方案设计合理。