Proposal of High Density Two-Bits-Cell Based NAND-Like Magnetic Random Access Memory

In this brief, we propose a Two-bits-cell based NAND-Like MRAM device. The structure is composed of several stacking cells sharing the same heavy metal and each cell is composed of two magnetic tunnel junctions (MTJs). Every two stacking MTJs share the same transistor and the demand of three-terminal bit cell for two access transistors is eliminated due to the contribution of NAND-Like structure, thus the area overhead is greatly reduced. For data storage, two steps are required to avoid disturbance in the programming stage after erasing original data, twice as much as data could be stored in comparison with traditional NAND-Like MRAM under the same duration. Thanks to a toggle-like writing scheme adopted in our proposed writing operation, low power consumption, low latency in the programming stage and field-free switching are reached. Based on the Two-bits-cell of our proposed structure, we present a multifunctional sensing circuit which senses two bits data and implements both logic and add operations in memory, which shows a good potential to be applied to the in-memory computing systems.