A hierarchical test generation approach for large controllers

A testing approach targeted at Hardware Description Language (HDL)-based specifications of complex control devices is proposed. For such architectures, gate-level test pattern generators require insertion of scan paths to enable the flat gate-level representations to be efficiently handled. In contrast, we present a testing methodology based on the hierarchical finite state machine model. Our approach allows the generation of compact test sets with very high stuck-at fault coverages, without any design-for-testability logic other than hardware reset. This method can be used any time the functional information is available together with the gate-level structural description. High fault coverages are achieved with smaller test lengths and execution times with respect to state-of-the-art gate-level test pattern generators.