Design of Spin-Torque Transfer Magnetoresistive RAM and CAM/TCAM with High Sensing and Search Speed

With a great scalability potential, nonvolatile magnetoresistive memory with spin-torque transfer (STT) programming has become a topic of great current interest. This paper addresses cell structure design for STT magnetoresistive RAM, content addressable memory (CAM) and ternary CAM (TCAM). We propose a new RAM cell structure design that can realize high speed and reliable sensing operations in the presence of relatively poor magnetoresistive ratio, while maintaining low sensing current through magnetic tunneling junctions (MTJs). We further apply the same basic design principle to develop new cell structures for nonvolatile CAM, and TCAM. The effectiveness of the proposed RAM, CAM and TCAM cell structures has been demonstrated by circuit simulation at 0.18 $ mu$m CMOS technology.