Download or read book Timing Analysis for Time predictable Architectures written by Amine Naji and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the rising complexity of the underlying computer hardware, the analysis of the timing behavior of real-time software is becoming more and more complex and imprecise. Time-predictable computer architectures thus have been proposed to provide hardware support for timing analysis. The goal is to deliver tighter worst-case execution time (WCET) estimates while keeping the analysis overhead minimal. These estimates are typically provided by standalone WCET analysis tools. The emergence of time-predictable architectures is, however, quite recent. While several designs have been introduced, efforts are still needed to assess their effectiveness in actually enhancing the worst-case performance. For many time-predictable hardware, timing analysis is either non-existing or lacking proper support. Consequently, time-predictable architectures are barely supported in existing WCET analysis tools. The general contribution of this thesis is to help filling this gap and turning some opportunities into concrete advantages. For this, we take interest in the Patmos processor. The already existing support around Patmos allows for an effective exploration of techniques to enhance the worst-case performance. Main contributions include: (1) Handling of predicated execution in timing analysis, (2) Comparison of the precision of stack cache occupancy analyses, (3) Analysis of preemption costs for the stack cache, (4) Preemption mechanisms for the stack cache, and (5) Prefetching-like technique for the stack cache. In addition, we present our WCET analysis tool Odyssey, which implements timing analyses for Patmos.

Download or read book Time Predictable Architectures written by Christine Rochange and published by John Wiley & Sons. This book was released on 2014-01-17 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: Building computers that can be used to design embedded real-time systems is the subject of this title. Real-time embedded software requires increasingly higher performances. The authors therefore consider processors that implement advanced mechanisms such as pipelining, out-of-order execution, branch prediction, cache memories, multi-threading, multicorearchitectures, etc. The authors of this book investigate the timepredictability of such schemes.

Download or read book Timing Analysis and Design Optimization for GALS Systems on Time predictable Multi core Architectures written by Zhenmin Li and published by . This book was released on 2016 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ubiquitous real-time embedded systems are defined as computer systems that constantly monitor, respond to, or control external environment. Both functional and temporal correctness should be guaranteed for such systems, especially safety-critical systems whose correct operations are vital to ensure the safety of the public and the environment. The synchronous approach supporting deterministic concurrency is widely adopted in the design and verification of real-time embedded applications. Due to the surge in the demand for tools that can be used to model, validate and synthesize asynchronous systems, a Model of Computation (MoC) named Globally Asynchronous Locally Synchronous (GALS) has been proposed, providing both asynchronous and synchronous concurrency while preserving the advantages of the synchronous approach. A system modelled using GALS MoC consists of a set of subsystems at the top level, called Clock-Domains (CDs), running asynchronously to each other. A CD comprises a set of reactions that are running concurrently and synchronously. Recently, the insatiable demand for performance due to the growing complexity and more stringent timing requirements of embedded applications make it inevitable to integrate more Processing Elements (PEs) in a single chip, forming multi-core architectures. Moreover, in order to meet the resource usage constraints, shared resources (such as shared memory and input/output) are typically found in multi-core architecture, which are accessed through a shared bus to which all the PEs are connected. Due to the lack of methodologies and tools for timing analysis and design optimization of GALS systems running on multi-core architectures, statically and accurately determining the timing characteristics of the systems still remains a challenge. In addition, the overhead of resolving contentions induced by accessing shared resources simultaneously cannot be underestimated because it may even offset the benefit brought by integrating multiple PEs. This thesis focuses on timing analysis and design optimization of GALS systems running on time-predictable multi-core architectures. Starting with a scalable Timing Analysis and Code Optimization (TACO) framework targeting a CD running on a tandem processor platform, a series of timing analysis and design optimization techniques are presented in this thesis. A methodology based on design space exploration is proposed for finding the schedule with Guaranteed Reaction Time (GRT) for a CD running on a customizable multi-core architecture. This methodology is further extended by incorporating a novel bus arbitration policy, named Application-Specific Time Division Multiple Access (ASTDMA), to improve the efficiency of bus bandwidth utilization and hence reduce the GRT for each CD in a GALS system. Finally, a methodology is presented for minimizing resource usage for a GALS system with asynchronous execution of CDs on a multi-core architecture with shared resources. Another novel bus arbitration policy, named weighted TDMA, is employed by this methodology in order to improve the efficiency of bus bandwidth utilization. Experimental results show that the proposed optimization techniques effectively improve the worst-case performance of the system while maintaining time-predictability. Due to the fact that the timing analysis is only achievable on a time-predictable execution platform, the details of the target hardware architectures are given for each technique presented in this thesis.

Download or read book Providing Predictability for High End Embedded Systems written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Real-Time systems require logical and temporal correctness. Temporal correctness implies that each task running on the system has a deadline that needs to be met. To ensure that the deadlines are met, the scheduler of a real-time system needs information about the worst-case execution time (WCET) of each task. The task of determining the WCET of a task on a particular architecture is called timing analysis. Analysis techniques are broadly classified as static and dynamic. Dynamic timing analysis does not provide safe WCET bounds. Static analysis cannot be used on modern processors with features like out-of-order execution, dynamic branch prediction and speculative execution. Such features, while improving the average-case performance, induce counter-intuitive timing behavior known as timing anomalies. Hence, designers of hard real-time systems are forced to use architectures with simple in-order pipelines. This thesis develops and demonstrates the benefits of a hybrid timing analysis technique (combining static and dynamic analysis) on a processor simulator and on FPGA hardware to provide tight and safe WCET bounds. The technique makes the following contributions: * It enhances the realm of design for hard real-time systems by allowing the designers to use complex out-of-order architectures that exhibit timing anomalies. * It eliminates the need for complex prototyping of hardware for static timing analysis since the analysis can be done directly on the actual hardware. This has the added advantage of eliminating timing inaccuracies arising out of variations in manufacturing technology. * The method helps manufacturers to protect their Intellectual Property by eliminating the need to disclose architectural details for the purpose of static timing analysis.

Download or read book Constructing Predictable Real Time Systems written by Alexander D. Stoyenko and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 335 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cache Modeling for Timing Analysis in Real Time Systems written by Yanhui Li and published by LAP Lambert Academic Publishing. This book was released on 2011-08 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Caches in Embedded Systems improve average case performance, but they are a source of unpredictability, especially in the worst case software timing analysis with the consideration of data caches. This is a critical problem in real-time systems, where tight Worst Case Execution Time (WCET) is required for their schedulability analysis. Few works have studied data cache impacts on the WCET of programs, but only for programs with no input-dependent data accesses. To provide an efficient and accurate analysis for input-dependent data accesses, we develop classified cache architecture and a WCET framework for the architecture. Our work classifies predictable and unpredictable accesses, then allocates them into predictable caches and unpredictable caches accordingly, and uses CME (Cache Miss Equations) and our reuse-distance-based algorithm for their timing analysis respectively. Compared with simulation, our analysis framework produces a very good WCET tightness, and our architecture creates almost no hardware overhead or performance degradation. In addition, we examine NP-completeness of WCET analysis. We also explore data allocation techniques to improve system performance.

Download or read book High Performance and Time Predictable Embedded Computing written by Pinho, Luis Miguel and published by River Publishers. This book was released on 2018-07-04 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nowadays, the prevalence of computing systems in our lives is so ubiquitous that we live in a cyber-physical world dominated by computer systems, from pacemakers to cars and airplanes. These systems demand for more computational performance to process large amounts of data from multiple data sources with guaranteed processing times. Actuating outside of the required timing bounds may cause the failure of the system, being vital for systems like planes, cars, business monitoring, e-trading, etc. High-Performance and Time-Predictable Embedded Computing presents recent advances in software architecture and tools to support such complex systems, enabling the design of embedded computing devices which are able to deliver high-performance whilst guaranteeing the application required timing bounds. Technical topics discussed in the book include: Parallel embedded platformsProgramming modelsMapping and scheduling of parallel computationsTiming and schedulability analysisRuntimes and operating systems The work reflected in this book was done in the scope of the European project P‑SOCRATES, funded under the FP7 framework program of the European Commission. High-performance and time-predictable embedded computing is ideal for personnel in computer/communication/embedded industries as well as academic staff and master/research students in computer science, embedded systems, cyber-physical systems and internet-of-things.

Download or read book Architecture of Computing Systems written by Christian Hochberger and published by Springer Nature. This book was released on 2021-07-14 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the proceedings of the 34th International Conference on Architecture of Computing Systems, ARCS 2021, held virtually in July 2021. The 12 full papers in this volume were carefully reviewed and selected from 24 submissions. 2 workshop papers (VEFRE) are also included. ARCS has always been a conference attracting leading-edge research outcomes in Computer Architecture and Operating Systems, including a wide spectrum of topics ranging from fully integrated, self-powered embedded systems up to high-performance computing systems. It also provides a platform covering newly emerging and cross-cutting topics, such as autonomous and ubiquitous systems, reconfigurable computing and acceleration, neural networks and artificial intelligence. The selected papers cover a variety of topics from the ARCS core domains, including heterogeneous computing, memory optimizations, and organic computing.

Download or read book Techniques for Building Timing Predictable Embedded Systems written by Nan Guan and published by Springer. This book was released on 2016-02-03 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes state-of-the-art techniques for designing real-time computer systems. The author shows how to estimate precisely the effect of cache architecture on the execution time of a program, how to dispatch workload on multicore processors to optimize resources, while meeting deadline constraints, and how to use closed-form mathematical approaches to characterize highly variable workloads and their interaction in a networked environment. Readers will learn how to deal with unpredictable timing behaviors of computer systems on different levels of system granularity and abstraction.

Download or read book Design Space Exploration and Resource Management of Multi Many Core Systems written by Amit Kumar Singh and published by MDPI. This book was released on 2021-05-10 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasing demand of processing a higher number of applications and related data on computing platforms has resulted in reliance on multi-/many-core chips as they facilitate parallel processing. However, there is a desire for these platforms to be energy-efficient and reliable, and they need to perform secure computations for the interest of the whole community. This book provides perspectives on the aforementioned aspects from leading researchers in terms of state-of-the-art contributions and upcoming trends.

Download or read book The Compiler Design Handbook written by Y.N. Srikant and published by CRC Press. This book was released on 2018-10-03 with total page 784 pages. Available in PDF, EPUB and Kindle. Book excerpt: Today’s embedded devices and sensor networks are becoming more and more sophisticated, requiring more efficient and highly flexible compilers. Engineers are discovering that many of the compilers in use today are ill-suited to meet the demands of more advanced computer architectures. Updated to include the latest techniques, The Compiler Design Handbook, Second Edition offers a unique opportunity for designers and researchers to update their knowledge, refine their skills, and prepare for emerging innovations. The completely revised handbook includes 14 new chapters addressing topics such as worst case execution time estimation, garbage collection, and energy aware compilation. The editors take special care to consider the growing proliferation of embedded devices, as well as the need for efficient techniques to debug faulty code. New contributors provide additional insight to chapters on register allocation, software pipelining, instruction scheduling, and type systems. Written by top researchers and designers from around the world, The Compiler Design Handbook, Second Edition gives designers the opportunity to incorporate and develop innovative techniques for optimization and code generation.

Download or read book Fast Efficient and Predictable Memory Accesses written by Lars Wehmeyer and published by Springer Science & Business Media. This book was released on 2006-09-08 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: Speed improvements in memory systems have not kept pace with the speed improvements of processors, leading to embedded systems whose performance is limited by the memory. This book presents design techniques for fast, energy-efficient and timing-predictable memory systems that achieve high performance and low energy consumption. In addition, the use of scratchpad memories significantly improves the timing predictability of the entire system, leading to tighter worst case execution time bounds.

Download or read book Architecture of Computing Systems ARCS 2008 written by Theo Ungerer and published by Springer Science & Business Media. This book was released on 2008-02-12 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the 21st International Conference on Architecture of Computing Systems, ARCS 2008, held in Dresden, Germany, in February 2008. The 19 revised full papers presented together with 2 keynote papers were carefully reviewed and selected from 47 submissions. The papers cover a wide spectrum reaching from pre-fabrication adaptation of architectural templates to dynamic run-time adaptation of deployed systems with special focus on adaptivity and adaptive system architectures. The papers are organized in topical sections on hardware design, pervasive computing, network processors and memory management, reconfigurable hardware, real-time architectures, organic computing, and computer architecture.

Download or read book Software Architecture and Design for Reliability Predictability written by Assefa D. Semegn and published by Cambridge Scholars Publishing. This book was released on 2011-09-22 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reliability prediction of a software product is complex due to interdependence and interactions among components and the difficulty of representing this behavior with tractable models. Models developed by making simplifying assumptions about the software structure may be easy to use, but their result may be far from what happens in reality. Making assumptions closer to the reality, which allows complex interactions and interdependences among components, results in models that are too complex to use. Their results may also be too difficult to interpret. The reliability prediction problem is worsened by the lack of precise information on the behavior of components and their interactions, information that is relevant for reliability modeling. Usually, the interactions are not known precisely because of subtle undocumented side effects. Without accurate precise information, even mathematically correct models will not yield accurate reliability predictions. Deriving the necessary information from program code is not practical if not impossible. This is because the code contains too much implementation detail to be useful in creating a tractable model. It is also difficult to analyze system reliability completely based on the program code. This book documents the resulting novel approach of designing, specifying, and describing the behavior of software systems in a way that helps to predict their reliability from the reliability of the components and their interactions. The design approach is named design for reliability predictability (DRP). It integrates design for change, precise behavioral documentation and structure based reliability prediction to achieve improved reliability prediction of software systems. The specification and documentation approach builds upon precise behavioral specification of interfaces using the trace function method (TFM). It also introduces a number of structure functions or connection documents. These functions capture both the static and dynamic behaviors of component based software systems. They are used as a basis for a novel document driven structure based reliability prediction model. System reliability assessment is studied in at least three levels: component reliability, which is assumed to be known; interaction reliability, a novel approach to studying software reliability; and service reliability, whose estimation is the primary objective of reliability assessment. System reliability can be expressed as a function of service reliability. A mobile streaming system, designed and developed by the author as an industrial product, is used as a case study to demonstrate the application of the approach.

Download or read book Advances in Aeronautical Informatics written by Umut Durak and published by Springer. This book was released on 2018-05-10 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: The history of flight started with the pioneer era. The introduction of mechanical controls (including hydraulics) then led to the second era. Later, with the utilization of computers and automation in aircraft, we reached the third era. Now, we are moving towards the fourth era of flight, namely Flight 4.0, which is characterized by “smart” and “connected” aircraft that extensively exploit emerging information and communication technologies. Aeronautical informatics is advancing rapidly through the synergy between information and communication technologies and aeronautics. Multi-core avionic platforms, wireless avionics networking, service-oriented architectures and IoT, data sciences and semantic infrastructures are shaping systems to come. Increasing autonomy requirements are challenging the community to investigate new ways to assure safety. Modern software engineering methodologies and real-time software techniques are altering the established development practice. Universities are starting to align their aerospace engineering and computer science curriculums in order to address this synergy. This book is a unique compilation of advancements in aeronautical informatics, introducing the changing technology landscape of flight with respect to a new push in information and communication technology.

Download or read book A Journey of Embedded and Cyber Physical Systems written by Jian-Jia Chen and published by Springer Nature. This book was released on 2020-07-30 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Open Access book celebrates Professor Peter Marwedel's outstanding achievements in compilers, embedded systems, and cyber-physical systems. The contributions in the book summarize the content of invited lectures given at the workshop “Embedded Systems” held at the Technical University Dortmund in early July 2019 in honor of Professor Marwedel's seventieth birthday. Provides a comprehensive view from leading researchers with respect to the past, present, and future of the design of embedded and cyber-physical systems; Discusses challenges and (potential) solutions from theoreticians and practitioners on modeling, design, analysis, and optimization for embedded and cyber-physical systems; Includes coverage of model verification, communication, software runtime systems, operating systems and real-time computing.

Download or read book Computer Safety Reliability and Security written by Frank Ortmeier and published by Springer. This book was released on 2012-09-11 with total page 537 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of 5 workshops co-located with SAFECOMP 2012, the 31st International Conference on Computer Safety, Reliability, and Security, held in Magdeburg, Germany, in September 2012. The 49 revised full papers presented were carefully reviewed and selected from numerous submissions. According to the workshops covered, the papers are organized in topical sections on: next generation of system assurance approaches for safety-critical systems (Sassur), architecting safety in collaborative mobile systems (ASCoMS), dependable and secure computing for large-scale complex critical infrastructures (DESEC4LCCI), ERCIM/EWICS/cyberphysical systems (ERCIM/EWICS), and on digital engineering (IWDE).