Low search power and high reliability 13T-4R MTJ based nonvolatile ternary content-addressable memory

Nonvolatile ternary content addressable-memory (NV-TCAM) has been widely researched because of its great advantages, such as, zero standby power consumption and compact area. However, previous NV-TCAMs suffer from process variation, DC current, and leakage current, leading to the search and write reliabilities degradation and high power consumption. In this paper, we propose a novel 13T-4R NV-TCAM cell with fully symmetric structure and a current limiter which improves the DC and leakage current problems of previous NV-TCAM cells. The proposed scheme is verified using HSPICE Monte Carlo simulation with 22-nm CMOS process and industry mimic MTJ model. The simulation results prove that the proposed scheme reduces the DC current by more than 60% and eliminates the leakage current, leading to the large power saving, while satisfies the target search yield of 4σ.