Abstract-This paper describes a deterministic placement method for standard cells which minimizes total power consumption and leads to a smooth temperature distribution over the die. It is based on the Quadratic Placement formulation, where the overall weighted net length is minimized. Two innovations are introduced to achieve the above goals. First, overall power consumption is minimized by shortening nets with a high power dissipation. Second, cells are spread over the placement area such that the die temperature profile inside the package is flattened. Experimental results show a significant reduction of the maximum temperature on the die and a reduction of total power consumption.

The performance of timing-driven placement methods depends strongly on the choice of the net model. In this paper a more precise net model is presented that does not increase numerical complexity. We introduce a method that replaces the clique model of a net by a tree model in the quadratic placement formulation. This improvement enables us to control the length of every tree segment separately. Furthermore, we present an analysis of the effects of every tree segment to the net delay. The result is in turn used to control the placement engine. Our presented results are based on legal placements. They show significant improvements over state-of-the art methods.

During the ispd05 placement contest, we employed the forcedirected approach Kraftwerk for global placement complemented by the network-flow based final placer Domino. These powerful and flexible tools for standard cell placement can cope with various placement objectives and design conditions.