A Two-Level Diagnostic Model for Digital Systems

This paper is concerned with the diagnosis of faulty parts in digital systems, including both the detection and location of such parts. The system model presented in this paper considers two levels: the part level at which detectability and diagnosability are defined, and the fault level at which testing is performed and at which functional units or portions thereof are defined. Parameters are defined and used in determining conditions for t-part detectability, t-part diagnosability without repair, and t-part diagnosability with repair. Several examples are presented with the development of the model and derivation of results. These examples illustrate the advantages and limitations of this model.