Minimizing channel density with movable terminals

Abstract

We give algorithms to minimize density for VLSI channel-routing problems with terminals that are movable subject to certain constraints. The main cases considered are channels with linear-order constraints, channels with linear-order constraints and separation constraints, channels with movable modules containing fixed terminals, and channels with movable modules and terminals. In each case we improve previous results for running time and space by a factor ofL/lgn andL, respectively, whereL is the channel length andn is the number of terminals.