Incremental physical design is an important methodology towards achieving design closure for high-performance large-scale circuits. Placement tools must accommodate incremental changes to the layout and netlist due to physical synthesis techniques without perturbing the original metrics. We present an incremental placement approach using floorplan sizing to manage the resources and demands of the whole chip region in order to accommodate the changes due to gate sizing and buffer insertion. The experimental results show that this approach can accommodate a wide range of incremental changes without a loss in wirelength and routability. Most important, it also maintains the stability of a placement such that the convergence of physical synthesis iterations can be greatly enhanced.
Chen Li 0004, Cheng-Kok Koh, Patrick H. Madden