Packer: a Switchbox Router Based on Conflict Elimination by Local Transformations*

PACKER is an algorithm for switchbox routing, based on a novel approach. In an initial phase, the connectivity of each net is established without taking the other nets into account. In general this will give rise to conflicts (short circuits). In the second stage the conflicts are removed iteratively using connectivity p e e ing local tmnsformations. They ”reshape” a net by displacing one of its segments without disconnecting it from the net. The transformations are applied in a systematic way using a scan line technique. The results obtained by PACKER are very positive: it solves all well-known “benchmark” examples.