The Myths of Coded Processing

• Published in: 2015 IEEE 17th International Conference on High Performance Computing and Communications, 2015 IEEE 7th International Symposium on Cyberspace Safety and Security, and 2015 IEEE 12th International Conference on Embedded Software and Systems pp. 1637 - 1644
• Main Authors: Braun, Juergen, Mottok, Juergen
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.08.2015
• Subjects: coded processing; diversity; Encoding; Error probability; fail-operational; fail-safe; failure probability; failure rate; fault-tolerant; Hamming distance; Hardware; IEC 61508; ISO 26262; Redundancy; reliability; residual error probability; Safely Embedded Software; Safety; safety measure; SES; Software
• DOI: 10.1109/HPCC-CSS-ICESS.2015.24

Safety of embedded systems has the highest priority because it helps contribute to customer confidence and thereby ensures growth of the new markets, like electromobility. In series production fail-safe systems as well as fault-tolerant systems are realized with redundant hardware concepts like dual core microcontrollers running in lock-step-mode to reach highest safety requirements given by standards, like ISO 26262 or IEC 61508. In contrast to the hardware redundancy approach, there are also approaches available with information-, time-and/or software-redundancy since several years. One of them is known as coded processing or AN-codes. Coded processing is capable of reducing redundancy in hardware by adding diverse redundancy in software. But the breakthrough of coded processing never took place. One reason for this seem to be the myths which are widely propagated on this subject and the hereby associated uncertainties. In this paper some myths are busted, like the usage of prime numbers as transformation factor A, the myth that greater transformation factors are better or the myth about the residual error probability defined as 1/A. Some of them have been propagated since 1989. The aim of this paper is to provide more clarity and understanding for this technique, perhaps to pave the way for further functional safety concepts based on coded processing approaches.