ISARA: An Island-Style Systolic Array Reconfigurable Accelerator Based on Memristors for Deep Neural Networks

The demand for edge artificial intelligence (AI) is significant, particularly in revolutionary technological areas such as the Internet of Things, autonomous driving, and industrial control. However, reliable and high-performance edge AI is still constrained by computing hardware, and improving the performance and reliability of edge AI accelerators remains a key focus for researchers. This work proposes a memristor/resistive random access memory (RRAM)-based island-style systolic array reconfigurable accelerator (ISARA) that meets the reliability and performance requirements of edge AI. Inspired by the island-style architecture of FPGAs, this work proposes a flexible-tile architecture based on RRAM processing element (PE) islands, optimizing the data flow within the systolic array. The design of network-on-chip reduces data processing latency. In addition, to enhance computational efficiency, this work incorporates a bit-fusion scheme within the flexible tile, which reduces analog-to-digital converter (ADC) power consumption and addresses the conductance variation of RRAM. To date, only a few works have completed the entire process from simulation, design, and fabrication to hardware testing. This work fully realizes the design and validation of a new accelerator based on RRAM chips, demonstrating the reliability of RRAM-based systolic array accelerators for the first time. After deploying algorithms, the hardware accelerator achieved recognition rates comparable to software. Compared to similar works, ISARA’s computational efficiency exceeds theirs and has flexible reconfigurability. The same deep neural network (DNN) models are adopted for evaluation and compared to other accelerators, and ISARA’s processing latency is reduced by 200 times.