scholarly journals Compiling real-time programs with timing constraint refinement and structural code motion

1995 ◽  
Vol 21 (5) ◽  
pp. 389-404 ◽  
Author(s):  
R. Gerber ◽  
Seongsoo Hong
Keyword(s):  
Real Time ◽  
Timing Constraint ◽  
Code Motion ◽  
Structural Code

scholarly journals Evaluating Latency in Multiprocessing Embedded Systems for the Smart Grid

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3322
Author(s):  
Sara Alonso ◽  
Jesús Lázaro ◽  
Jaime Jiménez ◽  
Unai Bidarte ◽  
Leire Muguira
Keyword(s):  
Operating System ◽  
Smart Grid ◽  
Real Time ◽  
Processing System ◽  
The Other ◽  
Programmable Logic ◽  
Detailed Characterization ◽  
Timing Constraint ◽  
Time Part

Smart grid endpoints need to use two environments within a processing system (PS), one with a Linux-type operating system (OS) using the Arm Cortex-A53 cores for management tasks, and the other with a standalone execution or a real-time OS using the Arm Cortex-R5 cores. The Xen hypervisor and the OpenAMP framework allow this, but they may introduce a delay in the system, and some messages in the smart grid need a latency lower than 3 ms. In this paper, the Linux thread latencies are characterized by the Cyclictest tool. It is shown that when Xen hypervisor is used, this scenario is not suitable for the smart grid as it does not meet the 3 ms timing constraint. Then, standalone execution as the real-time part is evaluated, measuring the delay to handle an interrupt created in programmable logic (PL). The standalone application was run in A53 and R5 cores, with Xen hypervisor and OpenAMP framework. These scenarios all met the 3 ms constraint. The main contribution of the present work is the detailed characterization of each real-time execution, in order to facilitate selecting the most suitable one for each application.

scholarly journals A Timing Constraint Search Technique for a TMO based Real-time Process

2006 ◽  
Vol 2 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Yoon-Seok Jeong ◽  
Tae-Wan Kim ◽  
Sun-Young Han ◽  
Chun-Hyon Chang
Keyword(s):  
Real Time ◽  
Time Process ◽  
Search Technique ◽  
Timing Constraint

A SYSTEM FOR VISUALIZING AND DEBUGGING DISTRIBUTED REAL-TIME SYSTEMS WITH MONITORING SUPPORT

1996 ◽  
Vol 06 (03) ◽  
pp. 355-400
Author(s):  
JEFFREY J.P. TSAI ◽  
YAO-DONG BI ◽  
STEVE J.H. YANG
Keyword(s):  
Real Time ◽  
Interaction Graph ◽  
Real Time Systems ◽  
Timing Behavior ◽  
Timing Constraint ◽  
Execution Traces ◽  
Target Program ◽  
Run Time ◽  
Time Systems ◽  
Process Interaction

Based on system execution traces, this paper presents a dynamic approach for visualizing and debugging timing constraint violations occurring in distributed real-time systems. The system execution traces used for visualization and debugging are collected during the execution of a target program in such a way that its run-time behavior is not interfered with. This is made possible by our non-interference distributed real-time monitoring system which is capable of collecting system’s run-time traces by monitoring and fetching the data passing through the internal buses of a target system. After the run-time data has been collected, the visualization and debugging activities then proceeded. The timing behavior of a target program is visualized as two graphs—the Colored Process Interaction Graph (CPIG) and the Dedicated Colored Process Interaction Graph (DCPIG). The CPIG depicts the timing behavior of a target program by graphically representing interprocess relationships during their communication and synchronization. The DCPIG can reduce visualization and debugging complexity by focusing on the portion of a target program which has direct or indirect correspondence with an imposed timing constraint. With the help of the CPIG and the DCPIG, a timing analysis method is used for computing the system-related timing statistics and analyzing the causes of timing constraint violations. A visualization and debugging system, called VDS, has been implemented using OpenWindows on Sun-4’s/UNIX workstations.

Timing constraint remapping to achieve time equi-continuity in distributed real-time systems

2001 ◽  
Vol 50 (12) ◽  
pp. 1310-1320 ◽  
Author(s):  
Minsoo Ryu ◽  
Jungkeun Park ◽  
Seongsoo Hong
Keyword(s):  
Real Time ◽  
Real Time Systems ◽  
Timing Constraint ◽  
Time Systems

Task Scheduling under Uncertain Timing Constraints in Real-Time Embedded Systems

2013 ◽  
pp. 211-235 ◽  
Author(s):  
Pranab K. Muhuri ◽  
K. K. Shukla
Keyword(s):  
Embedded Systems ◽  
Real Time ◽  
Task Scheduling ◽  
Resource Constraints ◽  
Systems Design ◽  
Task Completion ◽  
Timing Constraints ◽  
Timing Constraint ◽  
Processing Times ◽  
And Task

In real-time embedded systems, timeliness of task completion is a very important factor. In such systems, correctness of the output depends on the timely production of results in addition to the logical outcome of computation. Thus, tasks have explicit timing constraints besides other characteristics of general systems, and task scheduling aims towards devising a feasible schedule of the tasks such that timing constraints, resource constraints, precedence constraints, etc. are complied. In real-time embedded systems, the most important timing constraint of a task is the deadline, as tasks must be completed within this time. The next important timing constraint is the processing time, because a task occupies a processor only for this duration of time. However, in the early phase of real-time embedded systems design only an approximate idea of the tasks and their characteristics are known. As a result, uncertainty or impreciseness is associated with the task deadlines and processing times; hence, it is appropriate to use fuzzy numbers to model deadlines and processing times in real-time embedded systems. The chapter introduces a new method using mixed cubic-exponential Hermite interpolation technique for intuitively defining smooth Membership Functions (MFs) for fuzzy deadlines and processing times. The effect of changes in parameterized MFs on the task schedulability and task priorities are explained. Examples are given to demonstrate the significant features and better performance of the new technique.

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