Reconfigurable in-memory computing with resistive memory crossbar

Driven by recent advances in resistive random-access memory (RRAM), there have been growing interests in exploring alternative computing concept, i.e., in-memory processing, to address the classical von Neumann bottlenecks. Despite of their great promise in improving performance and energy efficiency, most existing works are built on the inherent matrix-vector multiplication capability of RRAM crossbar structure, and thus lack the flexibility to adapt to future market/technology induced changes in data-intensive applications. To address these challenges, we propose an in-memory reconfigurable architecture based on RRAM crossbar structure. For the first time, it achieves a full programmability across computation and storage, and thereby provides more flexibilities of partitioning the hardware resources based on applications' needs. We further develop two complete CAD design flows to facilitate development of applications written in hardware description languages (HDLs) for our architecture, based on: 1) adaption from existing tool set developed for FPGA, 2) a custom tool design optimized towards the new architecture. Our experiments show that, both design flows are effective in exploiting flexible resources offered by our architecture and thus achieves better efficiency than state-of-art FPGAs (30% improvement in performance with 66% reduction in area). In addition, compared to adapted design flow, our custom design flow achieves speedup by 3.3×, and further improves mapping quality.