Rescuing healthy cores against disabled routers

A router may be temporarily or permanently disabled in NoCs for several reasons such as saving power, occurring faults or testing. Disabling a router, however, may have a severe impact on the performance or functionality of the entire system if it results in disconnecting the core from the network. In this paper, we propose a deadlock-free routing algorithm which allows the core to stay connected to the system and continue its normal operation when its connected router is disabled. Our analysis and experiments show that the proposed technique has 100%, 93.60%, and 87.19% network availability by 100% packet delivery when 1, 2 and 3 routers are defunct or intentionally disabled. The algorithm provides adaptivity and it is lightweight, requiring one and two virtual channels along the X and Y dimension, respectively.