Reconfigurable Network-on-Chip for 3D Neural Network Accelerators

Parallel hardware accelerators for large-scale neural networks typically consist of several processing nodes, arranged as a multi- or many-core system-on-chip, connected by a network-on-chip (NoC). Recent proposals also benefit from the emerging 3D memory-on-logic architectures to provide sufficient bandwidth for neural networks. Handling the heavy traffic between neurons and memory and also the multicast-based inter-neuron traffic, which often varies over time, is the most challenging design consideration for the networks-on-chip in such accelerators. To address these issues, a reconfigurable network-on-chip architecture for 3D memory-on-logic neural network accelerators is presented in this paper. The reconfigurable NoC can adapt its topology to the on-chip traffic patterns. It can be also configured as a tree-like structure to support multicast-based neuron-to-neuron and memory-to-neuron traffic of neural networks. The evaluation results show that the proposed architecture can better manage the multicast-based traffic of neural networks than some state-of-the-art topologies and considerably increase throughput and power efficiency.