Fault Escapes in Duplex Systems

Hardware duplication techniques are widely used for concurrent error detection in dependable systems to ensure high availability and data integrity. These techniques are vulnerable to common-mode failures (CMFs). Use of duplex systems with diverse implementations of the two modules has been proposed in the past for protection against CMFs. In this paper, we define a category of faults, called non-self-testable faults that undermine the data integrity of dependable systems. These faults produce identical errors at the outputs of the two modules of a duplex system and can potentially be caused by CMFs. The main contributions of this paper are: (1) techniques that identify non-self-testable faults in duplex systems, and (2) design methods that reduce the number of non-selftestable faults by test point insertion. We show that our algorithm for identifying non-self-testable faults runs orders of magnitude faster than exact techniques with minimal loss of accuracy. Also, there is a signific...

• Type: Conference
• Year: 2000
• Where: VTS
• Authors: Subhasish Mitra, Nirmal R. Saxena, Edward J. McCluskey
• Keywords: Dependable Systems, Duplex Systems, Hardware, Non-self-testable Faults, VTS 2000