Memory-Efficient Architecture for Accelerating Generative Networks on FPGA

Generative adversarial networks (GANs) are a class of artificial intelligence algorithms used in unsupervised machine learning, implemented by a system of two neural networks: a generative network (generator) and a discriminative network (discriminator). These two networks compete with each other to perform better at their respective tasks. The generator is typically a deconvolutional neural network and the discriminator is a convolutional neural network (CNN). Deconvolution performs a fundamentally new type of mathematical operation which differs from convolution. While the FPGA-based CNN accelerators have been widely studied in prior work, the acceleration of deconvolutional networks on FPGA is rarely explored. This paper proposes a novel parametrized deconvolutional architecture based on an FPGA-friendly method, in contrast to the transposed convolution implementation in CPUs and GPUs. Hardware design templates which map this architecture to FPGAs are provided with configurable deconvolutional layer parameters. Furthermore, a memory-efficient architecture with a new tiling method is proposed to accelerate the generator of GANs, by storing all intermediate data in on-chip memories and significantly reducing off-chip data transfers. The performance of the proposed accelerator is evaluated using a variety of GANs on a Xilinx Zynq 706 board, which shows 2.3x higher speed and 8.2x off-chip memory access reduction than an optimized Vanilla FPGA design. Compared to the respective implementations on CPUs and GPUs, the achieved improvements are in the range of 30x-92x in speed over an Intel 8-core i7-950 CPU, and 8x-108x in terms of Performance-per-Watt over an NVIDIA Titan X GPU.