Memristor Crossbar Circuit for Ternary Content-Addressable Memory with Fine-Tuning Operation

Memristor-based ternary content-addressable memory (TCAM) has emerged as an alternative to conventional static random-access memory (SRAM)-based TCAM because of its high-density integration and zero-static energy consumption. Herein, 0T2R TCAM operation on a 32 × 32 passive memristor crossbar circuit is experimentally verified. The effective margin, which is the difference between the match case and 1-bit mismatch case, is improved through precise tuning operations. Moreover, the number of mismatch bits and match cases can be accurately detected thanks to the linear relationship between the number of mismatch bits and match-line current. In addition, the nonideal effects in the passive crossbar array including dynamic voltage drop and sneak current are analyzed through SPICE studies. These results indicate that the proposed TCAM operating conditions can ensure stable TCAM operation in larger arrays.