Online Self Testing for Real Time Systems

Online Self Testing for Real Time Systems A Survey on Different Architectures Used in Online Self Testing for Real Time Systems I.ABSTRACT On-line self-testing is the solution for detecting permanent and intermittent faults for non safety critical and real-time embedded multiprocessors. This paper basically describes the three scheduling and allocation policies for on-line self-testing. Keywords-components: MPSoC, On-line self-testing, DSM technology II.INTRODUCTION Real-time systems are very important parts of our life now a day to day. In the last few decades, we have been studied the time aspect of computations. But in recent years it has increase exponentially among the researchers and research school. There has been an eye catching growth in the count of real-time systems. Being used in domestic and industry production. So we can say that real-time system is a system which not only depends upon the correctness of the result of the system but also on the time at which the result is produced. The example of the real-time system can be given as the chemical and nuclear plant control, space mission, flight control systems, military systems, telecommunications; multimedia systems and so on all make use of real-time technologies. Testing is a fundamental step in any development process. It consists in applying a set of experiments to a system (system under test − SUT), with multiple aims, from checking correct functionality to measuring performance. In this paper, we are interested in so-called  black-box conformance testing, where the aim is to check conformance of the SUT to a given specification. The SUT is a â€Å"black box† in the sense that we do not have a model of it, thus, can only rely on its observable input/output behavior. Real time is measured by quantitative use of clock (real clock)[1].Whenever we quantify time by using the real clock we use real time. A system is called real time system when we need quantitative expression of time to describe the behavior of the used system. In our daily lives, we rely on systems that have underlying temporal constraints including avionic control systems, medical devices, network processors, digital video recording devices, and many other systems and devices. In each of these systems there is a potential penalty or consequence associated with the violation of a temporal constraint. a. ONLINE SELF TESTING Online self-testing is the most cost-effective technique which is used to ensure correct operation for microprocessor-based systems in the field and also improves their dependability in the presence of failures caused by components aging. DSM Technologies Deep submicron technology means, the use of transistors of smaller size with faster switching rates[2]. As we know from Moores law the size of transistors are doubled by every year in a system, the technology has to fit those inc in transistors in small area with better performance and low-power[4]. III. Different Architectures used in Online Self Testing in Real Time Systems. 1.The Architecture of the DIVA Processing In Memory Chip The DIVA system architecture was specially designed to support a smooth migration path for application software by integrating PIMs into conventional systems as seamlessly as possible. DIVA PIMs resemble, at their interfaces, commercial DRAMs, enabling PIM memory to be accessed by host software either as smart memory coprocessors or as conventional memory[2]. A separate memory to memory interconnect enables communication between memories without involving the host processor. PIM Array PIM to PIM Interconnect Fig.1: DIVA Architecture A parcel is closely related to an active message as it is a relatively lightweight communication mechanism containing a reference to a function to be invoked when the parcel is received. Parcels are transmitted through a separate PIM to PIM interconnect to enable communication without interfering with host memory traffic. This interconnect must support the dense packing requirement of memory devices and allow the addition or removal of devices from system. Each DIVA PIM chip is a VLSI memory device augmented with general purpose computing and communication hardware[3]. Although a PIM may consist of multiple nodes, each of which are primarily comprised of few megabyte of memory and a node processor. 2. Chip Multiprocessor Architecture (CMP Architecture) Chip multiprocessors are also called as multi-core microprocessors or CMPs for short ,these are now the only way to build high-performance microprocessors, for a number of reasons[6]. limiting acceptance of CMPs in some types of systems. Fig.2: The above figure shows the CMP Architecture[6] 3. SCMP Architecture: An Asymmetric Multiprocessor System-on-Chip Future systems will have to support multiple and concurrent dynamic compute-intensive applications, while respecting real-time and energy consumption constraints. Within this framework, an architecture, named SCMP has been presented[5]. This asymmetric multiprocessor can support dynamic migration and preemption of tasks, thanks to a concurrent control of tasks, while offering a specific data sharing solution. Its tasks are controlled by a dedicated HW-RTOS that allows online scheduling of independent real-time and non real time tasks. By incorporating a connected component labelling algorithm into this platform, we have been able to measure its benefits for real-time and dynamic image processing. In response to an ever increasing demand for computational efficiency, the performance of embedded system architectures have improved constantly over the years. This has been made possible through fewer gates per pipeline stage, deeper pipelines, better circuit designs, faster transistors with new manufacturing processes, and enhanced instruction level or data-level parallelism (ILP or DLP)[7]. An increase in the level of parallelism requires the integration of larger cache memories and more sophisticated branch prediction systems. It therefore has a negative impact on the transistors’ efficiency, since the part of these that performs computations is being gradually reduced. Switching time and transistor size are also reaching their minimum limits. The SCMP architecture has a CMP structure and uses migration and fast preemption mechanisms to eliminate idle execution slots. This means bigger switching penalties, it ensures greater flexibility and reactivity for real-time systems. Programming Model The programming model for the SCMP architecture is specifically adapted to dynamic applications and global scheduling methods. The proposed programming model is based on the explicit separation of the control and the computation parts. Computation tasks and the control task are extracted from the application, so as each task is a standalone program. The control task handles the computation task scheduling and other control functionalities, like synchronizations and shared resource management for instance. Each embedded application can be divided into a set of independent threads, from which explicit execution dependencies are extracted. Each thread can in turn be divided into a finite set of tasks. The greater the number of independent and parallel tasks are extracted, the more the application can be accelerated at runtime. Fig3: SCMP Processing As shown in Figure 9, the SCMP architecture is made of multiple PEs and I/O controllers. This architecture is designed to provide real-time guarantees, while optimizing resource utilization and energy consumption. The next section describes execution of applications in a SCMP architecture. When the OSoC receives an execution order of an application, its Petri Net representation is built into the Task Execution and Synchronization Management Unit (TSMU) of the OSoC. Then, the execution and configuration demands are sent to the Selection unit according to application status. They contain all of active tasks that can be executed and of coming active tasks that can be prefetched. Scheduling of all active tasks must then incorporate the tasks for the newly loaded application. If a non-configured task is ready and waiting for its execution, or a free resource is available, the PE and Memory Allocation Unit sends a configuration primitive to the Configuration Unit. Fig4:SCMP Architecture[5] Table Of Comparison   Ã‚   Name Of The Paper Year of Publication Author Limits The Architecture of the DIVA Processing In Memory Chip 2002 Jeff Draper, Jacqueline Chame, Mary Hall, Craig Steele, Tim Barrett, Jeff LaCoss, John Granacki, Jaewook Shin, Chun Chen, Chang Woo Kang, Ihn Kim, Gokhan Daglikoca This paper has described a detailed description of DIVA PIM Architecture. This paper having some issues for exploiting memory bandwidth, particularly the memory interface and controller, instruction set features for fine grained parallel operation, and mechanism for address translation. Chip Multiprocessor Architecture: Techniques to Improve Throughput and Latency 2007 KunleOlukotun, LanceHammond, James Laudon This work provides a solid foundation for future exploration in the area of defect-tolerant design. We plan to investigate the use of spare components, based on wearout profiles to provide more sparing for the most vulnerable components. Further, a CMP switch is only a first step toward the overreaching goal of designing a defect-tolerant CMP system. SCMP Architecture: An Asymmetric Multiprocessor System on-Chip for Dynamic Applications 2010 NicolasVentroux, Raphael David The new architecture, which has been called SCMP, consists of a hardware real-time operating system accelerator (HW-RTOS), and multiple computing, memory, and input/output resources. The overhead due to control and execution management is limited by our highly efficient task and data sharing management scheme, despite of using a centralized control. Future works will focus on the development of tools to ease the programmation of the SCMP architecture. Conclusion We have done a survey how on-line self-testing can be controlled in a real-time embedded multiprocessor for dynamic but non safety critical applications using different architectures. We analyzed the impact of three on-line self-testing architectures in terms of performance penalty and fault detection probability. As long as the architecture load remains under a certain threshold, the performance penalty is low and an aggressive self test policy, as proposed in can be applied to [8] D. Gizopoulos et al., Systematic Software-Based Self -Test for Pipelined Processors, Trans. on Vlsi Sys., vol. 16, pp. 1441-1453, 2008. such architecture. Otherwise, on-line self-testing should consider the scheduling decision for mitigating the overhead in detriment to fault detection probability. It was shown that a policy that periodically applies a test to each processor in a way that accounts for the idle states of processors, the test history and the task priority offers a good trade-off between the performance and fault detection probability. However, the principle and methodology can be generalized to other multiprocessor architectures. References [1] R. Mall. â€Å"Real-time system†: Theory and practice. Pearson Education, 3rd Edition, 2008. [2] Analysis of On-Line Self-Testing Policies for Real-Time Embedded Multiprocessors in DSM Technologies O. Heron, J. Guilhemsang, N. Ventroux et al 2010 IEEE. [3] Jeff Draper et al., The Architecture of the DIVA Processing In Memory Chip, ICS’02, June. [4] C. Constantinescu, â€Å"Impact of deep submicron technology on dependability of VLSI circuits†, IEEE DSN, pp. 205-209, 2002. [5] Nicolas Ventroux and Raphael David, â€Å"SCMP architecture: An Asymmetric Multiprocessor System-on-Chip for Dynamic Applications†, ACM Second International Forum on Next Generation Multicore/Many core Technologies, Saint Malo, France, 2010. [6] Chip Multiprocessor Architecture: Techniques to Improve Throughput and Latency. [7] Antonis Paschalis and Dimitris Gizopoulos â€Å"Effective Software-Based Self-Test Strategies for On-Line Periodic Testing of Embedded Processors†, DATE, pp.578-583,2004. IJSET 2014Page 1

Macbeth :: essays research papers

Macbeth Macbeth was a general of King Duncan’s Scottish Army, he started off to be a great and devoted man to King and country but many events occurred that lead to the development of many enemies and his death. Macbeth sends a letter to Lady Macbeth telling her of the witch’s proficies in which they said he would be king. After reading the letter a messenger came and told Lady Macbeth that King Duncan will be coming to dinner that evening, she quickly concludes that in order of Macbeth to be King, Duncan must die that very night, She knows that it will not be easy persuading Macbeth to go through with the murder, because she says â€Å"he is the milk of human kindness†. When Macbeth arrives at the castle Lady Macbeth greets him by telling him that they must kill Duncan, he first seems hesitant but Lady Macbeth assures him he will be king by the next day. Later that night Lady Macbeth drugged the king’s attendants when he was asleep, then she gives the signal for Macbeth to kill Duncan, so Macbeth enters Duncan’s room and draws his dagger and kills him, After the deed is done Macbeth wishes he hadn’t gone along with the murder, he expresses this by looking at his hands covered with Duncan’s blood and says â€Å"what a sorry sight†. After all the investigations the castle dismisses the case as the two attendants the murderers. Once Macbeth is crowned king of Scotland he thinks about the people who would have the closest idea that he was responsible for the murder of Duncan, he then realises the closest person would be Banquo who was there when the witches told the prophecies to Macbeth, and although Macbeth is unsure Banquo is already starting to suspect him of the murder. Days later Macbeth finds out that Banquo and Fleance are going hunting the next day, he firstly arranges a feast in honour of Banquo the day they go hunting to clear his name for any wrong doing, then he hires two assassins to kill Banquo and his son while they are hunting, but first he has to talk Lady Macbeth into it, he does so by scarring her, saying â€Å"we will eat our meals in fear and sleep in the affliction of the of these terrible dreams†. The next day just before the feast the assassins enter Macbeth’s room and tells him that they have killed Banquo but not his son, because he had fled before they could do so.

How and Why did Labor Unions Start Essay

Essentially, labor unions are associations of workers who are banded together for the purpose of improving their employment conditions and protecting themselves and their coworkers from economic and legal exploitation. Members of labor unions engage in collective bargaining with their employers, as well as general political activism. Labor unions are almost as old as America itself. Although primitive unions of carpenters and other tradespeople made an appearance in various cities in colonial America, the first national labor unions gained strength in the 1820s. During this time, workers banded together to reduce the working day from a grueling 12 hours to a more manageable 10 hours. In 1866, the Nation Labor Union persuaded Congress to cut the workday down to today’s eight hour standard. Labor Day, a holiday observed on the first Monday in September, is a creation of the organized labor movement. The day is intended to honor the achievements of American workers and the contributions they have made to the prosperity and strength of the United States. The first Labor Day celebration was organized by members of the Central Labor Union and held on 5 September 1882. Labor unions are legally recognized as representatives of workers in many industries in the United StatesLarger unions also typically engage in lobbying activities and electioneering at the state and federal level. Most unions in America are aligned with one of two larger umbrella organizations: the AFL-CIO created in 1955, and the Change to Win Federation which split from the AFL-CIO in 2005. Both advocate policies and legislation on behalf of workers in the United States and Canada, and take an active role in politics. The AFL-CIO is especially concerned with global trade issues. Although much smaller compared to their peak membership in the 1950s, American unions remain a prominent political factor, both through mobilization of their own memberships and through coalitions with like-minded activist organizations around issues such as immigrant rights, trade policy, health care, and living wage campaigns. To fight alleged employer anti-union programs, unions are currently advocating new â€Å"card check† federal legislation that would require employers to bargain with a union if more than 50% of workers signed forms, or â€Å"cards,† stating they wish to be represented by that union. The current procedure involves waiting  45 to 90 days for a federally supervised secret-ballot employee referendum on the subject.

Descriptive Essay - Original Writing - 1040 Words

Gulp, as I stared up at the towering tall roller coaster. Goosebumps covered my body. Butterflies fluttered in my stomach. It was our turn next, as the coaster came into view. When it came to a halt, I inched in the roller coaster, as fear oozed out of my eyes. Next, I clipped my seat belt in and forced the bar down, the lady soon was at my side and checking my seat belt. Her gentle hands grasped the strap, as she gave a few tugs here and there. When she put full pressure on the cold gray bar, it started to rest on my thighs. Instantly, the click sounded and the attractive lady disappeared to the next cart. In the distance, I could see her happy, joyful face before it fanished in the screaming mob. Before I knew it, my horrified look came back and the seat belt started to suffocate me. But I wanted to be more safe than sorry. This was my first time on Shivering Timbers ,and I was scared out of my skin. That’s when I remembered the time when I was scared to go on the log ride. We were in line, watching the logs drift down the river. Suddenly, I wanted to jump out of line because there was a ginormous, steep hill that we were going to encounter. Without warning, we stepped in the wet, slimy carts. We all noticed their were no seat belts. In a flash, goosebumps started spreading like a rash all over my body. Please can we leave, I thought to myself as my dad nudged me to move forward. I was praying that the ride would shut down before it was our turn. But none of thatShow MoreRelatedDescriptive Essay - Original Writing1110 Words   |  5 PagesI don’t know how I got to where I am, but I’m here now, and I have to win if I want to live. I am in a game, and in order to live, I have to escape. That’s the thing, though: I don’t know how to escape. I was running for my life aro und this old house that looked like it came straight out of a horror movie. I doubled over and held my head in pain as I saw the static, which meant it was coming. 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