A low overhead, fault tolerant and congestion aware routing algorithm for 3D mesh-based Network-on-Chips

• A fault tolerant routing algorithm (FT-DyXYZ) for 3D Network-on-Chip is presented.
• FT-DyXYZ has low overhead and utilizes proximity congestion to balance traffic.
• FT-DyXYZ outperforms planar-adaptive routing in fault free and faulty situations.
• FT-DyXYZ improves latency, throughput and saturation injection rate significantly.

Nowadays, three dimensional Network-On-Chips (NOCs) have emerged as most efficient and scalable communication structures for complex and high performance System-on-Chips (SOCs). These structures are so susceptible to manufacturing and runtime faults. Thus fault tolerant routing is essential to increase reliability and performance of NOC-based SOCs. In this paper, we propose FT-DyXYZ, an adaptive fault tolerant routing to tolerate permanent faulty links in 3D mesh based NOCs that uses proximity congestion information to balance traffic. Our routing achieves fault tolerance without using routing tables, redundancy or global information of paths and faults. To evaluate performance of our routing, we compared it with fault tolerant planar-adaptive routing in terms of average packet latency, throughput and reliability. Simulation results demonstrate significant improvement of saturation injection rate, average throughput and reliability of our routing under synthetic traffic patterns.