t-TDA-diagnosable systems

A testable diagnosis array (TDA) is proposed for carrying out system-level fault diagnosis (based on the PMC model) centrally and in a non-hard-core manner. This diagnostics device is constructed with simple reliable logic cells. A characterization of t-TDA-diagnosable systems, based on an algebraic relationship between the testing graph T_n of a system of n component and its corresponding TDA, is given. It is shown that the TDA performs the diagnosis correctly and reaches its stable state in a number of clock periods related to the t-diagnostic diameter of T. A special class of t-TDA-diagnosable systems is defined, and an example from that class is used to illustrate the diagnosability of a system using a TDA