A Three-Dimensional Networks-on-Chip Architecture with Dynamic Buffer Sharing

3D integration is a practical solution for overcoming the failure of Dennard scaling in future technology generations. This emerging technology stacks several die slices on top of each other on a single chip in order to provide higher-bandwidth and lower-latency than a 2D design due to extremely shorter inter-layer distances in the third dimension and. In this paper, we leverage the low-latency vertical links to address buffer management, one of the most important design and management issues in Network-on-Chip (NoC). To this end, we present VerBuS, an architecture for 3D routers with Vertical BUffer Sharing capability enabled by ultra-low latency vertical links of a 3D chip. VerBuS can share virtual channels (VC) between vertically stacked routers. This way, the buffering capacity of a highly loaded router is increased by using idle VCs of vertically adjacent routers. Experimental results show up to 20% improvement in NoC performance metrics over state-of-the-art 3D router designs.