A Low-Latency and High-Throughput Multiple-Level Arbitration Scheme Supporting Quality-of-Service in Optical On-chip Network

As a key technology in optical NoC design, the arbitration scheme should provide differential arbitration service with high throughput and low latency for various types and priorities of traffic in CMPs. In this work, we propose a fast hierarchical arbitration supporting Quality-of-Service. With a multi-priority data buffer queue, arbiters provide differential transmissions and guarantee service for all queues. Our arbiter also presents the transmit bound resource reservation scheme to reserve time slots for all nodes fairly. We propose fast arbitration with a layout of fast optical arbitration channels to decrease the arbitration period, thereby reducing packet transmitting delay. The simulation results show that with our hierarchical arbitration scheme, all nodes are allocated with almost equal service under various patterns; thus, the min-communication-bandwidth and max-transmit-delay is guaranteed to be 5% and 80 cycles under the overload demands. This scheme improves throughput by 17% compared to FeatherWeight under a self-similar traffic pattern and decreases arbitration delay by 15% to 2-pass arbitration.