TRACKER: A low overhead adaptive NoC router with load balancing selection strategy

The effectiveness of an adaptive router in a Network on Chip (NoC) is evaluated by the selection metric it uses and its impact on overall performance. In this paper, we propose a flit flow history based load balancing selection strategy that can be used in any adaptive routers for output port selection. Using this selection strategy, we propose an adaptive router TRACKER, that keeps track of flow of flits through all its ports and updates this tracked information to its neighbors in a cost effective manner. Routers make use of these flit flow estimates to compute a novel selection metric for output port selection of incoming flits. TRACKER outperforms the baseline adaptive router architectures using odd-even routing model with conventional selection metrics like count of free virtual channels, count of fluid buffers and buffer occupancy time at reachable downstream neighbors.