Incorporating Heterogeneous Redundancy in a Nanoprocessor for Improved Yield and Performance

Emerging nano-device based architectures are expected to experience high defect rates associated with the manufacturing process. In this paper, we introduce a novel built-in heterogeneous fault-tolerance scheme, which incorporates redundant circuitry into the design to provide fault tolerance. A thorough analysis of the new scheme was carried out for various system level metrics. The implementation and analysis were carried out on WISP-0, a stream processor implemented on the Nanoscale Application Specific Integrated Circuits (NASIC) fabric. We show that intelligent assignment of redundancy levels and nanoscale-voting strategies across WISP-0 greatly improves area, effective yield and performance for the nano-processor. The new scheme outperforms homogeneous schemes for a defect range of 3% to 9.75% where the metric used is the product of performance and effective yield.