A Novel 8T SRAM-Based In-Memory Computing Architecture for MAC-Derived Logical Functions

TL;DR

This paper introduces an 8T SRAM-based in-memory computing architecture capable of high-speed MAC and logical operations, leveraging charge-sharing and analog-to-digital decoding for efficient digital logic implementation.

Contribution

It presents a novel 8T SRAM architecture that enables reliable multi-bit MAC and logical functions with improved decoupling of read/write paths and an innovative decoding scheme.

Findings

Achieves 8-bit MAC and logic operations at 142.85 MHz

Latency of 0.7 ns for operations

Energy consumption of 56.56 fJ/bit per MAC

Abstract

This paper presents an in-memory computing (IMC) architecture developed on an 8x8 array of 8T SRAM cells. This architecture enables both multi-bit parallel Multiply-Accumulate (MAC) operations and standard memory processing through charge-sharing on dedicated read bit-lines. By leveraging the maturity of SRAM technology, this work introduces an 8T SRAM-based IMC architecture that decouples read and write paths, thereby overcoming the reliability limitations of prior 6T SRAM designs. A novel analog-to-digital decoding scheme converts the MAC voltage output into digital counts, which are subsequently interpreted to realize fundamental logic functions including AND/NAND, NOR/OR, XOR/XNOR, and 1-bit addition within the same array. Simulated in a 90 nm CMOS process at 1.8 V supply voltage, the proposed design achieves 8-bit MAC and logical operations at a frequency of 142.85 MHz, with a latency of 0.7 ns and energy consumption of 56.56 fJ/bit per MAC operation and throughput of 15.8 M operations/s.