Cool elevator: A thermal-aware routing algorithm for partially connected 3D NoCs

Abstract

Despite of high throughput and low fabrication cost of vertically partially connected 3D NoCs, thermal difficulties arise from poor heat dissipation and inappropriate traffic distribution of these kinds of 3D NoCs. This paper proposes an adaptive routing algorithm in order to manage thermal challenges in partially connected 3D NoCs. In the proposed routing algorithm, vertical links declare their availability/unavailability status to their neighbor nodes due to their current temperature. In this way, hot vertical links have a chance to reduce their traffic load and to cool down. In a predefined time periods vertical links update process is done to determine current hot and cool vertical links. In an updating time periods, cool vertical links are announced to the routers of each layer for transmitting packets to other layers. Access Noxim simulator is used to evaluates the routing algorithm in different partially 3D networks. Results show that the proposed routing algorithm decreases the number of overheated nodes by at least 74% and improves the thermal variance by at least 13%. These results are achieved within at most 10% overhead in average latency delay.