片上网络二维和三维结构的通信性能分析

Communication Performance Analysis of the NoCs in 2D and 3D Architectures

芯片集成技术的迅猛发展,使得片上网络从二维向三维扩展成为可能。研究表明三维片上网络因拓扑维度的增加而缩短了通信距离,极大地提升了网络的平均通信性能。本文对比分析了k-ary-2-mesh网络及其对应的三维网络在最差情形下的通信性能,得出了以下结论:三维网络的平均通信性能虽然更优,但受垂直信道影响其最差情形下的通信性能可能劣于其对应的二维网络。本文的分析基于网络演算理论,该理论广泛应用于计算信息流穿越各种网络元素的延迟上界。

Advanced integration technologies enable the construction of Network-on-Chip （NoC） from two dimensions to three dimensions. Studies have shown that 3D NoCs can improve the average communication performance because of the possibility of using the additional dimension to shorten the communication distance. In this paper, we present a comparative analysis on the worst-case communication performance in the regular k-ary-2-mesh networks and their 3D forms. We show that, though 3D networks achieve better average latency, this may not be the case for the worst-case performance mainly due to the constraints on vertical channels. Our analysis is based on network calculus, which allows to calculate the theoretical delay bounds for constrained flows traversing network elements.