Testing Random Defect and Process Variation Induced Comparison Faults of TCAMs With Asymmetric Cells

This paper presents a march-like testT_AC-P to cover comparison faults of ternary content addressable memories (TCAMs) with asymmetric cells. The T_AC-P only requires 4N Write operations and (3N+2B) Compare operations for an N ×B -bit TCAM with Hit and priority address encoder outputs. We show that the test also can cover search time failures induced by process variation in the comparison circuit of a TCAM. Furthermore, a test T_MF for match failures induced by the process variation in the comparison circuit of a TCAM is also presented.