Complementary 5T-4MTJ nonvolatile TCAM cell circuit with phase-selective parallel writing scheme

Abstract

Towards a compact and process-variation-tolerant nonvolatile ternary content-addressable memory (TCAM), we propose a novel complementary cell structure with just five transistors and four magnetic tunnel junction (MTJ) devices (5T-4MTJ). The complementary cell structure enlarges output voltage swing of each cell circuit together with match-line voltage swing in word circuit constructed by many bits of cell circuits, which eliminates search errors. We also propose a novel bit-parallel writing scheme, called phase-selective parallel writing, for the cell circuit. Every data is written into a complementary MTJ-device pair in two phases by selectively asserting bit-lines during 0-write phase or 1-write phase, not directly assigning write data to the bit-lines. Consequently, the phase-selective parallel writing scheme enables four-phase write for the proposed 5T-4MTJ-based word circuit.