Hardware Description Levels and Test for Complex Circuits

A complex circuit can be described at the structural level (gate or register transfer description), at the functional level (state based description) or at a higher level (algorithmic or behavioral level). Test methods have been studied at each level but present severe constraints : complexity problems for the structural level, and error hypotheses for the other levels. After a presentation of the state of the art, we show that the practical solution is a multilevel approach using the techniques of each type of these methods.