This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Timing Correctness in Safety-Related Automotive Software
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 12, 2011 by SAE International in United States
Annotation ability available
Automotive applications classed as safety-related or safety-critical are now important differentiating technologies in the automotive industry. The emergence of safety standard ISO 26262 underlines the increasing importance of safety in automotive software. As well as functional requirements, hard real-time requirements are of crucial importance to safety-related software as there is a need to prove that the system functionality is fulfilled, even in worst-case scenarios.
Measurement-based WCET (Worst-Case Execution Time) analysis combines on-target timing measurements with static analysis of program structure to calculate predicted worst-case paths and times. This is in contrast to traditional end-to-end timing measurements, which give no confidence that the worst-case path is actually tested and no insight into the location of any timing problems that do emerge.
This paper presents the principles of WCET analysis alongside the results of using a commercially available WCET toolkit within the development of a commercial, safety-related software project. The observed benefits include greatly increased confidence in timing correctness, even in worst-case scenarios, understanding of timing variability, location of timing hot-spots and greatly reduced costs of optimization.
|Technical Paper||An Integrated Timing Analysis Methodology for Real-Time Systems|
|Technical Paper||Fault Injection for Simulation of Electronic Control Units|
|Technical Paper||Hardware-in-the-Loop Test of Battery Management Systems|
CitationZalman, R., Griessing, A., and Emberson, P., "Timing Correctness in Safety-Related Automotive Software," SAE Technical Paper 2011-01-0449, 2011, https://doi.org/10.4271/2011-01-0449.
- ISO/DIS, 26262 Road vehicles - Functional safety, Parts 1-10, 2009.
- Klobedanz, K., Kuznik, C., Thuy, A., and Mueller, W., “Timing modeling and analysis for AUTOSAR-based software development - a case study,” in Design, Automation & Test in Europe Conference & Exhibition (DATE), 2010, pp. 642-645.
- Kästner, D et al., “Timing Validation of Automotive Software,” in ISoLA, vol. 17, 2008, pp. 93-107.
- Rapita Systems Ltd., RapiTime White Paper, 2008, http://www.rapitasystems.com/system/files/RapiTime-WhitePaper.pdf
- Bernat, G. et al., “Identifying Opportunities for Worst-case Execution Time Reduction in an Avionics System,” Ada User Journal, vol. 28, no. 3, pp. 189-194, September 2007.
- IEC, 61508 Functional safety of electrical/electronic/programmable electronic safety-related systems, Parts 1-7, 2000.
- Infineon, “SafeTcore-I Safety Driver User's Manual,” Release v2.0, 2010.
- Infineon, “SafeTcore AudoFS Safety Manual,” Release v0.9, 2010.
- AUTOSAR - AUTomotive Open Svstem ARchitecture. [Online]. http://www.autosar.org
- AUTOSAR Development Partnership, Release 3.1, 2008, http://www.autosar.org/index.php?p=3&up=2&uup=0.
- Johansson, R and Heurung, T, “ISO-26262 Implications on Timing of Automotive E/E System Design Processes,” in SAE World Congress & Exhibition, Detroit, 2009.