Reliability, Reconfiguration, and Spare Allocation Issues in Binary-Tree Architectures Based on Multiple-Level Redundancy

The locally redundant modular tree (LRMT) schemes offer high yield and reliability for trees of relatively few levels but are less effective for large binary trees due to the imbalance of reliability of different levels. We present a new multiple-level redundancy tree (MLRT) architecture that combines modular schemes with level-oriented schemes leading to better yield and reliability. The MLRT structure enhances the wafer yield to significant levels by offering separate layers of protection for random and clustered defects. Unlike most existing techniques, we perform a more accurate reliability analysis by taking into account both switch and link failures. A new measure called the marginal switch to processing element area ratio (MSR) is introduced to precisely characterize the effect of switch complexity on the reliability of the redundant system. A systematic method for the optimal distribution of spare modules of the MLRT structure is also presented. Our analyses show that the MLRT structure offers higher yield and system reliability than LRMT and subtree-oriented fault-tolerance (SOFT) structures.