Buffer block planning for interconnect planning and prediction

Abstract

This paper studies buffer block planning (BBP) for interconnect planning and prediction in deep submicron designs. We first introduce the concept of feasible region for buffer insertion, and derive its closed-form formula. We observe that the feasible region for a buffer is quite large in general even under fairly tight delay constraint. Therefore, it gives us a lot of flexibility to plan for buffer locations. We then develop an effective BBP algorithm to perform buffer clustering such that design objectives such as overall chip area and the number of buffer blocks can be minimized. Effective BBP can plan and predict system-level interconnect by construction, so that accurate interconnect information can be used in early design stages to ensure design closure.