AER-SRT: Scalable Spike Distribution by Means of Synchronous Serial Ring Topology Address Event Representation

Given the massive number of interconnects in Spiking Neural Networks (SNNs), distributing spikes effciently becomes a critical issue for the efficient hardware emulation of large-scale SNNs. In this work, the AER-SRT (Address Event Representation over Synchronous Serial Ring Topology) architecture for spike transmission is proposed. AER-SRT is a light, easily scalable, packet-based solution implemented with high-speed serial link for multi-chip SNN communication. The channel uses a unidirectional, point-to-point connection between nodes, which provides a high transmission speed. Events (spikes) are distributed among all the nodes in a ring-topology pipeline fashion and the synchronous AER guarantees a collision-free scheme. The fast speed and efficient channel usage limits the spike distribution time to values that allow real-time operation for network sizes that can be calculated with simple design equations. Also, in the proposed communication protocol there is no specific or master node, so new nodes can be added to the ring by simply modifying two configuration parameters. As a proof of concept, a prototype of the architecture has been implemented and tested on FPGA development boards.