Realizing In-Memory Computing using Reliable Differential 8T SRAM for Improved Latency

Traditional von Neumann computing architectures suffer from high energy and lower speed as compared to the requirements of modern applications like those required in neural network accelerators. A modified differential eight transistor (8+T) static random access memory (SRAM)-based in-memory computing (IMC) structure was presented for realizing bit-wise Boolean logic operations. The 8+T SRAM-IMC is designed at the 32 nm technology node with throughput of 2.1849, 2.4815, 2.5795, 2.6240, 2.6495, 2.6619, 2.6690, 2.6732, and 2.6749 giga outputs per second for 0.5 to 1.3 V supply voltage range, respectively. The differential 8T cell used to implement logic operations supports NAND and NOR operations with minimal overhead while also performing the standard storage operation with added stability over the conventional 6T and 8T SRAM cells. The SRAM-IMC offers reliable Boolean logic operations by using asymmetric sensing strategy for all process corners, TT, SS, SF, FS, and FF for an operating temperature range of 220 K to 400 K. Monte Carlo simulation considering global threshold voltage deviation of 50 mV was performed for various operating conditions to study the impact of variations on design parameters such as latency.