CORAL: Coarse-grained reconfigurable architecture for Convolutional Neural Networks

Convolutional Neural Network (CNN) has become one of the most successful technologies for visual classification and other applications. As CNN models continue to evolve and adopt different kernel sizes in various applications, it is necessary for the hardware architecture to support reconfigurability. Previous FPGAs and programmable ASICs are fine-grained reconfigurable but with energy efficiency compromise. Considering specific features of CNNs, this paper presents an energy efficient coarse-grained reconfigurable architecture, denoted as CORAL. An application-specific configuration neural block is proposed for convolution operations with reconfigurable data quantization to reduce both energy consumption and on-chip memory requirements. An optimal data loading strategy is presented for CORAL to achieve the best energy efficiency. Experimental results show that CORAL improves 80.0% energy efficiency while reduces 78.9% chip area and 81.0% reconfiguration time compared with the best up-to-date programmable ASIC solution.