A robust ECO engine by resource-constraint-aware technology mapping and incremental routing optimization

Abstract

ECO re-mapping is a key step in functional ECO tools. It implements a given patch function on a layout database with a limited spare cell resource. Previous ECO re-mapping algorithms are based on existing technology mappers. However, these mappers are not designed to consider the resource limitation and thus the corresponding ECO results are generally not good enough, or even become much worse when the spare cells are sparse. In this paper, we proposed a new solution for ECO remapping. It includes a robust resource-constraint-aware technology mapper and a fast incremental router for wire-length optimization. Moreover, we adopt a Pseudo-Boolean solver to search feasible solutions when the spare cells are sparse. Our experimental results show that our ECO engine can outperform the previous tool in both runtime and routing costs. We also demonstrate the robustness of our tool by performing ECOs on various spare cell limitations.