Repair of RAMs with clustered faults

A graph-theoretic formulation for memory repair in the presence of clustered faults is presented. This approach is based on the use of variable-cell-size grids (VCS grids). As VCS grids can be represented by bipartite graphs, the reconfiguration problem for clustered faults can also be formulated as a vertex covering problem. Hence, graph-based reconfiguration algorithms developed by previous authors can be extended to exploit clustered fault distributions. Algorithms for memory repair that do not suffer from the restrictions imposed by previous algorithms for clustered faults are developed. A heuristic repair algorithm that has both improved performance and lower execution time than previous repair algorithms is presented