A Prototype-Based Framework to Design Scalable Heterogeneous SoCs with Fine-Grained DFS

TL;DR

This paper introduces Vespa, an open-source framework for designing scalable, heterogeneous SoCs with fine-grained dynamic frequency scaling, enabling flexible architecture exploration and runtime optimization.

Contribution

It presents Vespa, a novel framework that supports multi-replica accelerators, frequency islands, and runtime monitoring for FPGA-based heterogeneous SoCs.

Findings

Effective exploration of design options including accelerator replication and frequency scaling.

Demonstrated runtime monitoring of interconnect traffic and accelerator performance.

Validated on 4x4 tile-based systems showing flexible optimization capabilities.

Abstract

Frameworks for the agile development of modern system-on-chips are crucial to dealing with the complexity of designing such architectures. The open-source Vespa framework for designing large, FPGA-based, multi-core heterogeneous system-on-chips enables a faster and more flexible design space exploration of such architectures and their run-time optimization. Vespa, built on ESP, introduces the capabilities to instantiate multiple replicas of the same accelerator in a single network-on-chip node and to partition the system-on-chips into frequency islands with independent dynamic frequency scaling actuators, as well as a dedicated run-time monitoring infrastructure. Experiments on 4-by-4 tile-based system-on-chips demonstrate the possibility of effectively exploring a multitude of solutions that differ in the replication of accelerators, the clock frequencies of the frequency islands, and the tiles' placement, as well as monitoring a variety of statistics related to the traffic on the interconnect and the accelerators' performance at run time.