Locating Open-Channels in Octagon Networks on Chip-Microprocessors

Networks-on-chip (NoCs) provide the essential communication infrastructure for building today's on-chip multiprocessors. Albeit mesh is commonly used as the underlying interconnection architecture, other regular topologies such as octagons or spidergons, find recent applications to hybrid, small-world, and smart networks. Aggressive technology scaling, however, makes NoCs susceptible to manufacturing defects and causes failures in their operations. This paper presents a distributed, on-line built-in-self-test (BIST) mechanism that targets open faults on communication channels in an octagon NoC. We introduce a novel test scheduling scheme that exploits the knowledge of multithreading for reducing the overall test time with minimal degradation of performance. We evaluate the proposed test scheme for a 16-bit octagon NoC and report experimental results.