Click here to flash read.
We develop new algorithmic techniques for VLSI detailed routing. First, we
improve the goal-oriented version of Dijkstra's algorithm to find shortest
paths in huge incomplete grid graphs with edge costs depending on the direction
and the layer, and possibly on rectangular regions. We devise estimates of the
distance to the targets that offer better trade-offs between running time and
quality than previously known methods, leading to an overall speed-up. Second,
we combine the advantages of the two classical detailed routing approaches -
global shortest path search and track assignment with local corrections - by
treating input wires (such as the output of track assignment) as reservations
that can be used at a discount by the respective net. We show how to implement
this new approach efficiently.
No creative common's license