ASDR: An Application-Specific Deadlock-Free Routing for Chiplet-Based Systems

Yaoyao Ye, Zixuan Liu, Jungan Liu, Li Jiang

Abstract: In a modular chiplet-based system, the conventional monolithic system-on-chip (SoC) is divided into individual chiplets. Although deadlock-free on-chiplet networks can be ensured with traditional NoC deadlock-free techniques, deadlocks may still occur once cyclic dependency is formed among multiple chiplets. In order to enhance network performance for real applications, we propose an application-specific deadlock-free routing method (ASDR) for modular chiplet-based systems. By utilizing application-specific traffic information, the proposed ASDR method is able to customize an optimal deadlock-free routing solution for each real application at the minimum cost of network performance. Secondly, we propose a greedy-choice strategy based search algorithm to speed up the search for the optimal routing solutions. Thirdly, we propose a new load-balancing cost function for the greedy search, which further enhances the communication performance by improving the load balancing on each boundary router. Comparison results show that the proposed application-oriented deadlock-free routing method would reduce the number of prohibited turns on boundary routers by up to 87.5% as compared to the existing application-agnostic methods. Besides, the proposed greedy search achieves 104 times of speedup than the traditional time-consuming recursive search. In overall, as compared to existing application-agnostic methods, it improves the saturation throughput by 4.2%~53.9% under synthetic traffic and up to 24.6% speed up on real applications.