A deductive technique for diagnosis of bridging faults

Abstract

A deductive technique is presented that uses voltage testing for the diagnosis of single bridging faults between two gate input or output lines and is applicable to combinational or full-scan sequential circuits. For defects in this class of faults the method is accurate by construction while making no assumptions about the logic-level wired-AND/OR behaviour. A path-trace procedure starting from failing outputs deduces potential lines associated with the bridge. The information obtained from the path-trace from failing outputs is combined using an intersection graph to make further deductions. All candidate faults are implicitly represented, thereby obviating the need to enumerate faults and hence allowing the exploration of the space of all faults. Results are provided for all large ISCAS89 benchmark circuits.