Cross-coupled 4T2R multi-logic in-memory computing circuit design

Abstract

Resistive random access memory (RRAM) is viewed as the next-generation memory model, surpassing the constraints of traditional random access memory. Given its non-volatile nature, which lessens static power consumption, RRAM boasts significant computing-in-memory (CIM) potential. We herein present a four-transistor/two-resistor cross-coupling structure based on RRAM. In this structure, two RRAMs are situated in opposite directions, a configuration referred to as reverse coding. This structure provides the flexibility and reconfigurability to adjust the RRAM connections, facilitating various CIM operations in fewer cycles. A full adder design was developed and its feasibility was validated through simulations. Monte Carlo analysis ensures the accuracy of logic operations, even while encountering significant resistance fluctuations. This approach effectively mitigates the resistance crossover observed in existing RRAM CIMs. Compared with previous methodologies, the proposed structure achieves greater robustness with fewer cycle counts and RRAM numbers, The comparison of our approach with state-of-the-art Boolean logic circuits for RRAM architecture shows significant improvement in both delay (1.4–4.1 × ) and the number of RRAM (1.2–6.6 × ).