A WCET Test Method Based on Associative Process Communication

2014 ◽  
Vol 577 ◽  
pp. 865-872
Author(s):  
Jun Yi Li ◽  
Yi Zhang ◽  
Ren Fa Li
Keyword(s):  
Real Time ◽  
Test Method ◽  
Basic Block ◽  
Worst Case ◽  
Real Time System ◽  
The Real ◽  
Process Communication ◽  
Associative Process ◽  
Worst Case Execution Time ◽  
Time Requirements

The Real-time system estimates the worst-case execution time (WCET) of the program to ensure the real-time requirements of the system. In this paper, a test method based on Associative Process Communication (APC) is put forward. First it tests the WCET value of basic blocks of ICFG through the use of APC algorithm, and then estimates the WCET by analyzing the worst execution path of the basic block. APC test method tests all benchmarks of Mälardalen. And the test results show that the proposed test method is precise and effective, and the test error is within the theoretical analysis.

scholarly journals A compiler framework for the reduction of worst-case execution times

2010 ◽  
Vol 46 (2) ◽  
pp. 251-300 ◽  
Author(s):  
Heiko Falk ◽  
Paul Lokuciejewski
Keyword(s):  
Real Time ◽  
Code Generation ◽  
Optimization Techniques ◽  
Design Flow ◽  
Tool Support ◽  
Worst Case ◽  
Real Time System ◽  
Worst Case Execution Time ◽  
Compiler Framework ◽  
Time Systems

Abstract The current practice to design software for real-time systems is tedious. There is almost no tool support that assists the designer in automatically deriving safe bounds of the worst-case execution time (WCET) of a system during code generation and in systematically optimizing code to reduce WCET. This article presents concepts and infrastructures for WCET-aware code generation and optimization techniques for WCET reduction. All together, they help to obtain code explicitly optimized for its worst-case timing, to automate large parts of the real-time software design flow, and to reduce costs of a real-time system by allowing to use tailored hardware.

Dynamic Partitioned Cache Memory for Real-Time MPSoCs with Mixed Criticality

2016 ◽  
Vol 25 (06) ◽  
pp. 1650062 ◽  
Author(s):  
Gang Chen ◽  
Kai Huang ◽  
Long Cheng ◽  
Biao Hu ◽  
Alois Knoll
Keyword(s):  
Real Time ◽  
Cache Memory ◽  
Time System ◽  
Worst Case ◽  
Real Time System ◽  
Average Performance ◽  
Shared Cache ◽  
Worst Case Execution Time ◽  
The One ◽  
Major Factors

Shared cache interference in multi-core architectures has been recognized as one of major factors that degrade predictability of a mixed-critical real-time system. Due to the unpredictable cache interference, the behavior of shared cache is hard to predict and analyze statically in multi-core architectures executing mixed-critical tasks, which will not only result in difficulty of estimating the worst-case execution time (WCET) but also introduce significant worst-case timing penalties for critical tasks. Therefore, cache management in mixed-critical multi-core systems has become a challenging task. In this paper, we present a dynamic partitioned cache memory for mixed-critical real-time multi-core systems. In this architecture, critical tasks can dynamically allocate and release the cache resourse during the execution interval according to the real-time workload. This dynamic partitioned cache can, on the one hand, provide the predicable cache performance for critical tasks. On the other hand, the released cache can be dynamically used by non-critical tasks to improve their average performance. We demonstrate and prototype our system design on the embedded FPGA platform. Measurements from the prototype clearly demonstrate the benefits of the dynamic partitioned cache for mixed-critical real-time multi-core systems.

Pendekatan Permodelan Masa Untuk Analisis Penjadualan Dalam Pembangunan Perisian Berasaskan Komponen

2012 ◽  
Author(s):  
Dayang Norhayati Abang Jawawi ◽  
Radziah Mohamad ◽  
Rosbi Mamat ◽  
Safaai Deris ◽  
Mohd Zulkifli Mohd Zaki
Keyword(s):  
Real Time ◽  
Scheduling Algorithm ◽  
Schedulability Analysis ◽  
Worst Case ◽  
Real Time System ◽  
Temporal Modeling ◽  
Temporal Models ◽  
Real Performance ◽  
Time Requirements ◽  
Time Systems

Dalam mereka bentuk sesebuah perisian masa–nyata terbenam, perkara penting yang perlu dititikberatkan ialah mengambil kira keperluan masa–nyata perisian tersebut. Kebolehan meramal dan menganalisis masa boleh menjamin keutuhan sesebuah sistem masa–nyata terbenam. Keperluan pemasaan bagi sistem masa–nyata terbenam mestilah dimodelkan dengan jelas semasa fasa keperluan dan fasa reka bentuk. Ini bertujuan untuk mengelakkan ralat permasaan berlaku semasa berada di lapangan dan menyebabkan kos yang banyak bagi kerja–semula pada peringkat akhir pembangunan. Analisis penjadualan merupakan alatan asas untuk menyemak ketepatan masa bagi sesebuah aplikasi masa–nyata. Kaedah analisis ini membolehkan proses menyemak faktor kekangan masa dengan meramal kes perlakuan terburuk bagi sesebuah sistem masa–nyata semasa algoritma penjadualan diaplikasikan. Kertas kerja ini mencadangkan satu pendekatan permodelan pemasaan di dalam pembangunan perisian yang berasaskan komponen dan menunjukkan bagaimana ramalan prestasi masa–nyata boleh dibuat berdasarkan model pemasaan tersebut. Satu eksperimen yang melibatkan kajian kes sistem masa–nyata terbenam telah direka bentuk untuk menunjukkan pendekatan yang dicadangkan ini dan juga mengesahkan keputusan ramalan prestasi sebenar perisian masa–nyata terbenam tersebut. Kata kunci: Sistem masa–nyata terbenam; analisis penjadualan; perisian berasaskan komponen An important issue in designing embedded real–time (ERT) software is the consideration for real–time requirements of the software. The abilities to predict and analyze timing are key requirements for reliable ERT systems. The temporal requirements of the ERT system must be explicitly modeled during requirements and design phases to avoid timing error in the field and costly late rework. Scheduling analysis is a fundamental tool for checking timing correctness of a real–time application. It allows checking timing constraints by predicting the worst–case behavior of a real–time system when a scheduling algorithm is applied. The aims of this paper are to propose an approach which enables temporal modeling and to demonstrate prediction of real–time performance based on the temporal models in component–based software development. An experiment on case–study was designed, to demonstrate the approach and to validate the predicted results against the real performance of an ERT software. Key words: Embedded real–time systems; schedulability analysis; component–based software

scholarly journals Formal Verification of a Power Controller Using the Real-Time Model Checker UPPAAL

1999 ◽  
Vol 6 (8) ◽  
Author(s):  
Klaus Havelund ◽  
Kim G. Larsen ◽  
Arne Skou
Keyword(s):  
Real Time ◽  
Product Line ◽  
Model Checker ◽  
Time Model ◽  
Real Time System ◽  
The Real ◽  
Time Requirements ◽  
Hard Real Time ◽  
Audio Video ◽  
And Control

A real-time system for power-down control in audio/video components<br />is modeled and verified using the real-time model checker UPPAAL. The<br />system is supposed to reside in an audio/video component and control (read from and write to) links to neighbor audio/video components such as TV, VCR and remote–control. In particular, the system is responsible for the powering up and down of the component in between the arrival of data, and in order to do so in a safe way without loss of data, it is essential that no link interrupts are lost. Hence, a component system is a multitasking system with hard real-time requirements, and we present techniques for modeling time consumption in such a multitasked,<br />prioritized system. The work has been carried out in a collaboration between Aalborg University and the audio/video company B&O. By modeling the system, 3 design errors were identified and corrected, and the following verification confirmed the validity of the design but also revealed the necessity for an upper limit of the interrupt frequency. The resulting design has been implemented and it is going to be incorporated as part of a new product line.

Real-Time System for Sending Data from Three Clients to One Server with MATLAB

2015 ◽  
Vol 2 (1) ◽  
pp. 35-41
Author(s):  
Rivan Risdaryanto ◽  
Houtman P. Siregar ◽  
Dedy Loebis
Keyword(s):  
Information System ◽  
Real Time ◽  
Time System ◽  
Real Time System ◽  
The Real ◽  
Performance Time ◽  
Data Process ◽  
Effectiveness And Efficiency

The real-time system is now used on many fields, such as telecommunication, military, information system, evenmedical to get information quickly, on time and accurate. Needless to say, a real-time system will always considerthe performance time. In our application, we define the time target/deadline, so that the system should execute thewhole tasks under predefined deadline. However, if the system failed to finish the tasks, it will lead to fatal failure.In other words, if the system cannot be executed on time, it will affect the subsequent tasks. In this paper, wepropose a real-time system for sending data to find effectiveness and efficiency. Sending data process will beconstructed in MATLAB and sending data process has a time target as when data will send.

Single Depth View Based Real-Time Reconstruction of Hand-Object Interactions

2021 ◽  
Vol 40 (3) ◽  
pp. 1-12
Author(s):  
Hao Zhang ◽  
Yuxiao Zhou ◽  
Yifei Tian ◽  
Jun-Hai Yong ◽  
Feng Xu
Keyword(s):  
Real Time ◽  
Synthetic Data ◽  
Real Data ◽  
Depth Image ◽  
Real Time System ◽  
The Real ◽  
Time Performance ◽  
Contact Constraint ◽  
Object Shapes ◽  
Object Interactions

Reconstructing hand-object interactions is a challenging task due to strong occlusions and complex motions. This article proposes a real-time system that uses a single depth stream to simultaneously reconstruct hand poses, object shape, and rigid/non-rigid motions. To achieve this, we first train a joint learning network to segment the hand and object in a depth image, and to predict the 3D keypoints of the hand. With most layers shared by the two tasks, computation cost is saved for the real-time performance. A hybrid dataset is constructed here to train the network with real data (to learn real-world distributions) and synthetic data (to cover variations of objects, motions, and viewpoints). Next, the depth of the two targets and the keypoints are used in a uniform optimization to reconstruct the interacting motions. Benefitting from a novel tangential contact constraint, the system not only solves the remaining ambiguities but also keeps the real-time performance. Experiments show that our system handles different hand and object shapes, various interactive motions, and moving cameras.

A Survey of Real-Time Industrial Wireless LAN Research

2015 ◽  
Vol 738-739 ◽  
pp. 1105-1110 ◽  
Author(s):  
Yuan Qing Qin ◽  
Ying Jie Cheng ◽  
Chun Jie Zhou
Keyword(s):  
Real Time ◽  
Future Development ◽  
Wireless Lan ◽  
State Of The Art ◽  
The State ◽  
Local Networks ◽  
The Real ◽  
Time Requirements ◽  
And Performance ◽  
Fundamental Mechanism

This paper mainly surveys the state-of-the-art on real-time communicaton in industrial wireless local networks(WLANs), and also identifys the suitable approaches to deal with the real-time requirements in future. Firstly, this paper summarizes the features of industrial WLANs and the challenges it encounters. Then according to the real-time problems of industrial WLAN, the fundamental mechanism of each recent representative resolution is analyzed in detail. Meanwhile, the characteristics and performance of these resolutions are adequately compared. Finally, this paper concludes the current of the research and discusses the future development of industrial WLANs.

Hardware-in-the-loop simulation for real-time software verification of an autonomous underwater robot

2016 ◽  
Vol 4 (3) ◽  
pp. 163-181
Author(s):  
Pouria Sarhadi ◽  
Reza Nad Ali Niachari ◽  
Morteza Pouyan Rad ◽  
Javad Enayati
Keyword(s):  
Software Engineering ◽  
Real Time ◽  
Autonomous Systems ◽  
Systems Design ◽  
Development Stage ◽  
Underwater Robot ◽  
Real Time System ◽  
Content Type ◽  
The Real ◽  
Time Performance

Purpose The purpose of this paper is to propose a software engineering procedure for real-time software development and verification of an autonomous underwater robotic system. High performance and robust software are one of the requirements of autonomous systems design. A simple error in the software can easily lead to a catastrophic failure in a complex system. Then, a systematic procedure is presented for this purpose. Design/methodology/approach This paper utilizes software engineering tools and hardware-inthe-loop (HIL) simulations for real-time system design of an autonomous underwater robot. Findings In this paper, the architecture of the system is extracted. Then, using software engineering techniques a suitable structure for control software is presented. Considering the desirable targets of the robot, suitable algorithms and functions are developed. After the development stage, proving the real-time performance of the software is disclosed. Originality/value A suitable approach for analyzing the real-time performance is presented. This approach is implemented using HIL simulations. The developed structure is applicable to other autonomous systems.

Use of Measurements in Worst-Case Execution Time Estimation for Real-Time Systems

2021 ◽  
Author(s):  
Jessica Junia Santillo Costa ◽  
Romulo Silva de Oliveira ◽  
Luis Fernando Arcaro
Keyword(s):  
Real Time ◽  
Execution Time ◽  
Time Estimation ◽  
Real Time Systems ◽  
Worst Case ◽  
Worst Case Execution Time ◽  
Time Systems

Real-time engine model development based on time complexity analysis

2021 ◽  
pp. 146808742110397
Author(s):  
Haotian Chen ◽  
Kun Zhang ◽  
Kangyao Deng ◽  
Yi Cui
Keyword(s):  
Real Time ◽  
Time Complexity ◽  
Complexity Analysis ◽  
High Accuracy ◽  
The Real ◽  
Cycle Simulation ◽  
Crank Angle ◽  
Time Requirements ◽  
Improved Model ◽  
Simulation Time

Real-time simulation models play an important role in the development of engine control systems. The mean value model (MVM) meets real-time requirements but has limited accuracy. By contrast, a crank-angle resolved model, such as the filling -and-empty model, can be used to simulate engine performance with high accuracy but cannot meet real-time requirements. Time complexity analysis is used to develop a real-time crank-angle resolved model with high accuracy in this study. A method used in computer science, program static analysis, is used to theoretically determine the computational time for a multicylinder engine filling-and-empty (crank-angle resolved) model. Then, a prediction formula for the engine cycle simulation time is obtained and verified by a program run test. The influence of the time step, program structure, algorithm and hardware on the cycle simulation time are analyzed systematically. The multicylinder phase shift method and a fast calculation method for the turbocharger characteristics are used to improve the crank-angle resolved filling-and-empty model to meet real-time requirements. The improved model meets the real-time requirement, and the real-time factor is improved by 3.04 times. A performance simulation for a high-power medium-speed diesel engine shows that the improved model has a max error of 5.76% and a real-time factor of 3.93, which meets the requirement for a hardware-in-the-loop (HIL) simulation during control system development.

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