A Deep - Submicron Steiner Tree ?

A-Tree is a rectilinear Steiner tree in which every sink is connected to a driver by a shortest length path, while simultaneously minimizing total wire length. This paper presents a polynomial approximation algorithm for the generalized version of A-Tree problem with upper-bounded delays along each path from the driver to the sinks and with restrictions on the number of Steiner nodes. We refer to it as "Deep-submicron Steiner tree" as minimizing the number of Steiner nodes is crucial for signal integrity issues in deep-submicron very-large-scaled-integrated-circuit (VLSI) designs. The idea behind the algorithm is to control two parameters in order to construct a feasible (with respect to the paths delays and the number of Steiner nodes) tree of small cost. The simulation results show the high eeciency of our approach.