Configuring an Embedded Neuromorphic Coprocessor Using a RISC-V Chip for Enabling Edge Computing Applications

Neuromorphic hardware shows promising potential for employment in edge computing applications, as it can provide real-time and low-power elaboration of complex data directly on edge using computational paradigm based on Spiking Neural Networks (SNNs). However, such systems cannot be deployed as edge devices by themselves, as they require an external host for configuration and data input management. In this paper, we present a chip-level integrated system performing on-edge configuration of a neuromorphic platform. The proposed solution makes use of two existing open-source platforms: the low-power RISC-V processor Rocket Chip and the digital SNN processor ODIN. We built the two systems into a single SoC using the Chipyard framework, and connected them by designing a communication interface using ODIN's SPI and AER input/output ports. We validated the system by RTL simulation of a synfire chain running on ODIN, where Rocket Chip sets up configuration of the network, triggers the first spike, then collects the simulation results. The synthesized design utilizes a modest amount of resources on a PYNQ-Z2 board: 16% of LUT slices, 11% of Block RAMs and 8 pins, leaving plenty of room to integrate other peripherals or systems. The present work represents a first step towards seamless integration of neuromorphic technologies with state-of-the-art processors, improving on the ease of use of neuromorphic devices and leading the way into widespread use of SNN coprocessors in edge computing applications.