Fault Emulation for Dependability Evaluation of VLSI Systems

Advances in semiconductor technologies are greatly increasing the likelihood of fault occurrence in deep-submicrometer manufactured VLSI systems. The dependability assessment of VLSI critical systems is a hot topic that requires further research. Field-programmable gate arrays (FPGAs) have been recently pro posed as a means for speeding-up the fault injection process in VLSI systems models (fault emulation) and for reducing the cost of fixing any error due to their applicability in the first steps of the development cycle. However, only a reduced set of fault models, mainly stuck-at and bit-flip, have been considered in fault emulation approaches. This paper describes the procedures to inject a wide set of faults representative of deep-submicrometer technology, like stuck-at, bit-flip, pulse, indetermination, stuck-open, delay, short, open-line, and bridging, using the best suitable FPGA- based technique. This paper also sets some basic guidelines for comparing VLSI systems in terms of their availability and safety, which is mandatory in mission and safety critical application contexts. This represents a step forward in the dependability benchmarking of VLSI systems and towards the definition of a framework for their evaluation and comparison in terms of performance, power consumption, and dependability.