Crosstalk-Aware Automated Mapping for Optical Networks-on-Chip

Abstract

Optical networks-on-chip (NoCs) provide a promising answer to address the increasing requirements of ultra-high bandwidth and extremely low power consumption. Designing a photonic interconnect, however, involves a number of challenges that have no equivalent in the electronic domain, particularly the crosstalk noise, which affects the signal-to-noise ratio (SNR) possibly resulting in an inoperable architecture and hence constraining the network scalability. In this article, we point out the implications of application-driven task mapping on crosstalk effects. We motivate the main rationale of our work and provide a formalization of the problem. Then we propose a class of algorithms that automatically map the application tasks onto a generic mesh-based photonic NoC architecture such that the worst-case crosstalk is minimized. We also present a purpose-built experimental setup used for evaluating several architectural solutions in terms of crosstalk noise and SNR. The setup is used to collect extensive results from several real-world applications and case studies. The collected results show that the crosstalk noise can be significantly reduced by adopting our approach, thereby allowing higher network scalability, and can exhibit encouraging improvements over application-oblivious architectures.