Abstract
Threshold voltage assignment is a very effective technique to reduce leakage power consumption in modern integrated circuit (IC) design. As feature size continues to decrease, the layout constraints (called MinIA constraints) on the implant area, which determines the threshold voltage of a device, are becoming increasingly difficult to satisfy. It is necessary to take these constraints into consideration during the placement stage. [1] proposes to resolve the MinIA constraint violations of a given placement by performing simultaneous detailed placement and threshold voltage refinement. They first present an optimal and efficient mixed integer-linear programming (MILP)-based algorithm to handle intra-row MinIA constraints. We then extend the MILP-based algorithm to handle both inter-row and intrarow MinIA constraints. Our algorithm guarantees to fix all MinIA constraint violations. Experimental results demonstrate that our algorithm only perturb the original placement and threshold voltage assignment solutions minimally to eliminate all violations and are fast in practice.