Traffic-Balanced Routing Algorithm for Irregular Mesh-Based On-Chip Networks

摘要

On-chip networks (OCNs) have been proposed to solve increasing scale and complexity of the designs in nano-scale multi-core VLSI designs. The concept of irregular meshes is an important issue because IPs of different sizes may be supported by various vendors. In order to solve routing problems in irregular meshes, modified routing algorithms to detour oversized IPs (OIPs) are needed. However, directly applying fault-tolerant routing algorithms may cause two serious problems: 1) heavy traffic loads around OIPs and 2) unbalanced traffic loads in irregular meshes. In this paper, we propose an OIP Avoidance Pre-Routing (OAPR) algorithm to solve the aforementioned problems. The proposed OAPR can make traffic loads evenly spread on the networks and shorten average paths of packets. Therefore, the networks using the OAPR have lower latency and higher throughput than those using fault-tolerant routing algorithms. In our experiments, four different cases are simulated to demonstrate that the proposed OAPR improves 13.3%~100% sustainable throughputs than two previous fault-tolerant routing algorithms. Moreover, the hardware overhead of the OAPR is less than 1% compared to the cost of a whole router. Hence, the proposed OAPR algorithm has good performance and is practical for irregular mesh-based OCNs.