Fault-resilient NoC router with transparent resource allocation

Abstract

The current trend of aggressive technology scaling results in a decrease in system's reliability. This motivates investigation of fault-resilient architectures which provide graceful degradation of system's functionality. In this paper, three novel fault-resilient Network-on-Chip (NoC) router architectures are proposed. These architectures, exploit the regularity of the router and reallocate available existing and spare units to maintain functionality of certain turns. The resource reallocation is performed transparently from system's resource manager and is based on predefined priorities. A new metric for architecture reliability comparison based on reliability block diagrams is introduced. In contrast to Silicone Protection Factor (SPF) metric, the proposed metric also takes into account the areas of different units. Area overhead and reliability of proposed architectures are compared with Triple Modular Redundancy (TMR) and Unit-Duplication mechanisms. All proposed architectures showed remarkable reliability improvement compared to original, TMR and Unit Duplication architectures; while at the same time, their area overhead is less than or equal to unit-duplication mechanisms.