With the increasing density of VLSI circuits, the interconnection wires are getting
packed even closer. This has increased the effect of interaction between these wires on
circuit performance and hence, the importance of controlling crosstalk. We consider the
gridded channel routing problem where, specifically, the channel has 3 routing layers in
the VHV configuration. Given a horizontal track assignment for the nets, we present an
optimal algorithm for minimizing the crosstalk between vertical wiring segments in the
channel by finding an optimal vertical layer assignment for them. We give an algorithm
that minimizes total crosstalk between vertical wires on the same V layer on adjacent
columns of the grid in O(ν logν) time using O(ν) memory, where the channel has ν
columns. We then extend this algorithm to consider crosstalk between wires in nonadjacent
columns and between wires on different layers. Finally, we show how our
algorithms can be extended to take crosstalk tolerance specifications for nets into
account.
Minimum Crosstalk Vertical Layer Assignment for Three-Layer VHV Channel Routing