Designer fault models for VLSI

Describes a simple abstract specification formalism for a functional block, describes some of the properties of these specifications and their relationship to the design process. The author looks at a simple description of what `faulty´ means and describes what a fault model is in terms of his simple abstract specification. Using this framework, he then describes various fault models, showing that new fault models can assist in the design process. This is an example of the power of formal specification. It helps demonstrate that something is over specified. In fact, the new fault models help to highlight the over specification that occurs early in circuit design process