Locality aware redundancy allocation in nanoelectronic systems

A high level of redundancy is required to deal with the challenge of high defect and fault rates in nano environments. The reconfigurability of nano devices and the regular structure of nano fabrics make reconfiguration based repair an essential approach for both defect and fault tolerance. Ideally, repair based approaches have the best hardware efficiency when full sharing of redundancy is achievable. However, nanoelectronic systems are subject to strict constraints on localized interconnections, which limit the sharing of redundant resources to within a small neighborhood. To more fully understand this challenge, we provide a model for the issue of redundant resource sharing under locality constraint. Our model captures the redundancy sharing essence of a system, and is applicable to any specific topology or layout of a nanoelectronic system. Based on this model, defect tolerance can be well defined, and can be addressed by existing algorithms. In addition, we provide discussion and algorithms for online fault tolerance for various system models. Overall, this paper provides a new framework and novel solutions to a the problem of reliability in nanoelectronic environments, where locality constraint for redundancy sharing plays an important role in developing defect / fault tolerance schemes.