Buffer block planning for interconnect-driven floorplanning

Jason Cong, Tianming Kong, David Zhigang Pan

Abstract: We study buffer block planning for interconnect-driven floorplanning in deep submicron designs. We first introduce the concept of feasible region (FR) for buffer insertion, and derive closed-form formula for FR. We observe that the FR for a buffer is quite large in general even under fairly tight delay constraints. Therefore, FR gives us a lot of flexibility to plan for buffer locations. We then develop an effective buffer block planning (BBP) algorithm to perform buffer clustering such that the overall chip area and the buffer block number can be minimized. To the best of our knowledge, this is the first in-depth study on buffer planning for interconnect-driven floorplanning with both area and delay consideration.