SPRINT: A High-Performance, Energy-Efficient, and Scalable Chiplet-Based Accelerator With Photonic Interconnects for CNN Inference

Chiplet-based convolution neural network (CNN) accelerators have emerged as a promising solution to provide substantial processing power and on-chip memory capacity for CNN inference. The performance of these accelerators is often limited by inter-chiplet metallic interconnects. Emerging technologies such as photonic interconnects can overcome the limitations of metallic interconnects due to several superior properties including high bandwidth density and distance-independent latency. However, implementing photonic interconnects in chiplet-based CNN accelerators is challenging and requires combined effort of network architectural optimization and CNN dataflow customization. In this article, we propose SPRINT, a chiplet-based CNN accelerator that consists of a global buffer and several accelerator chiplets. SPRINT introduces two novel designs: (1) a photonic inter-chiplet network that can adapt to specific communication patterns in CNN inference through wavelength allocation and waveguide reconfiguration, and (2) a CNN dataflow that can leverage the broadcasting capability of photonic interconnects while minimizing the costly electrical-to-optical and optical-to-electrical signal conversions. Simulations using multiple CNN models show that SPRINT achieves up to 76% and 68% reduction in execution time and energy consumption, respectively, as compared to other state-of-the-art chiplet-based architectures with either metallic or photonic interconnects.