A design of response analyzers with self-distinguishability in built-in self-test

In the BIST (built-in self-test) scheme, the occurrence of faults in BIST circuits, e.g., test pattern generators and test response analyzers, causes unreliable testing of chips, so that it results in field defects of the chips and yield loss. In this study, we focus on a concurrent testability of BIST circuits. Testing a circuit-under-test, a concurrently testable BIST circuit can test itself, and distinguish the faults in the BIST circuits from those in the circuit-under-test based on an obtained signature. We propose a concurrently testable response analyzer, called an encoding-based response analyzer, and present an instance of encoding-based response analyzer, which is based on cyclic codes. Furthermore, we propose a new measure, called a self-distinguishability, to show the concurrent testability. Experimental results show the relationship between the self-distinguishability and area overhead for the proposed encoding-based response analyzers.