A Reconfigurable Inference Processor for Recurrent Neural Networks Based on Programmable Data Format in a Resource-Limited FPGA

An efficient inference processor for recurrent neural networks is designed and implemented in an FPGA. The proposed processor is designed to be reconfigurable for various models and perform every vector operation consistently utilizing a single array of multiply-accumulate units with the aim of achieving a high resource efficiency. The data format is programmable per operand. The resource and energy efficiency are 1.89MOP/LUT and 263.95GOP/J, respectively, in Intel Cyclone-V FPGA. The functionality has been verified successfully under a fully-integrated inference system.