In‐memory multibit multiplication and accumulation based on an automatic pulse generation circuit

Computing‐in‐memory (CIM) is a promising technique for solving the ‘memory wall’ and ‘power consumption wall’ problems. However, calculations in the analog domain are limited in terms of accuracy and sensitivity to process, voltage, and temperature changes. In this study, the authors proposed a CIM multiply‐and‐accumulate (MAC) circuit in which the MAC result was reflected by the pulse edge and converted into the final digital output using a dual‐edge counter quantization circuit, thereby improving the accuracy of the MAC operation and reducing the difficulty of quantization. The performance of the proposed CIM circuit was evaluated using a 28‐nm process. It could achieve 4‐bit multiplication without errors, with an energy efficiency of 24.38 to 670.86 TOPS/W. In this study, the authors proposed a computing‐in‐memory multiply‐and‐accumulate (CIM MAC) circuit that could generate pulses spontaneously. The MAC result was reflected by the pulse edge and converted into the final digital output using a quantization circuit, improving the accuracy of the MAC operation and reducing the difficulty of quantization.