Abstract
In this paper, we propose a high performance broadcasting mechanism for irregular topologies in NoC based processors with low hardware cost in deadlock-free design. Subnetting is an efficient method to restrict the area of broadcasts in manycore processors. For the topologies of application mappings are usually irregular during a sustained scheduling, recent researches mainly focus on the subnetting mechanism for irregular topology. The existing subnetting mechanisms divide the NoC into subnets according to the topology of application mappings precisely, which we denote as the most fitted subnetting (MFS). In MFS, however, only a few of links in subnet are fully utilized, which means the average load on links are higher than expected. In this paper, we propose a subnetting mechanism for any irregular topologies, using physical subnet to supply routing paths for broadcasts in logical subnet. The design of deadlock-free routing algorithm is also simplified due to our subnetting mechanism, in which only two bits of registers are required in router of NoC. Simulation shows that the mechanism we propose could reduce the latency in NoC by 11%, comparing with the existing subnetting scheme.