IMFlexCom: Energy Efficient In-Memory Flexible Computing Using Dual-Mode SOT-MRAM

In this article, we propose an In-Memory Flexible Computing platform (IMFIexCom) using a novel Spin Orbit Torque Magnetic Random Access Memory (SOT-MRAM) array architecture, which could work in dual mode: memory mode and computing mode. Such intrinsic in-memory logic (AND/OR/XOR) could be used to process data within memory to greatly reduce power-hungry and long distance massive data communication in conventional Von Neumann computing systems. A comprehensive reliability analysis is performed, which confirms similar to 90mV and similar to 10mV (worst-case) sense margin for memory and in-memory logic operation in variations on resistance-area product and tunnel magnetoresistance. We further show that sense margin for in-memory logic computation can be significantly increased by increasing the oxide thickness. Furthermore, we employ bulk bitwise vector operation and data encryption engine as case studies to investigate the performance of our proposed design. IMFlexCom shows similar to 35x energy saving and similar to 18x speedup for bulk bitwise in-memory vector AND/OR operation compared to DRAM-based in-memory logic. Again, IMFlexCom can achieve 77.27% and 85.4% lower energy consumption compared to CMOS-ASIC- and CMOL-based Advanced Encryption Standard (AES) implementations, respectively. It offers almost similar energy consumption as recent DW-AES implementation with 66.7% less area overhead.