No abstract

This paper compares two fault injection techniques: scan chain implemented fault injection (SCIFI), i.e. fault injection in a physical system using built in test logic, and fault injection in a VHDL software simulation model of a system. The fault injections were used to evaluate the error detection mechanisms included in the Thor RISC microprocessor, developed by Saab Ericsson Space AB. The Thor microprocessor uses several advanced error detection mechanisms including control flow checking, stack range checking and variable constraint checking. A newly developed tool called FIMBUL (Fault Injection and Monitoring using BUilt in Logic), which uses the Test Access Port (TAP) of the Thor CPU to do fault injection, is presented. The simulations were carried out using the MEFIS-TO-C tool and a highly detailed VHDL model of the Thor processor. The results show that the larger fault set available in the simulations caused only minor differences in the error detection distribution compared to SCIFI and that the overall error coverage was lower using SCIFI (90-94% vs. 94-96% using simulation based fault injection). Overview of the Thor processorThe Thor microprocessor is designed and sold by Saab Ericsson Space AB. It is a 32-bit RISC processor based on a stack-oriented instruction set architecture and is intended for embedded real-time applications with high dependability requirements. The Thor processor has onchip support for real-time processing specifically for the Ada language including task scheduling and dispatch, communication between tasks, time handling, accurate delays and fast interrupt handling. The support for dependability includes several internal error detection mechanisms and the possibility to run the processor in a pair configuration with a comparator function (master/slave comparator configuration).

In this paper, we present a new fault injection tool called GOOF1 (Generic Object-Oriented Fault Injection). GOOFI is designed to be adaptable to various tat& systems and different fault injection techniques. The tool is highly portable between different host platfornis since it relies on the Java prograrnniing language and A SQL conipatible database. The ciirrent version of the tool supports pre-riintinie Software Impleniented Faiilt Injection and Scan-Chain Inzplemented Fault Injection.

No abstract

No abstract