Virtual Tracks in Innovus

Each off-grid rectangle must be made on-grid in order for Innovus to recognize it. This is accomplished using virtual tracks.

Certain libraries require the creation of thousands of virtual tracks because of the presence of off-grid geometries, which must be avoided during routing. The following figure shows virtual tracks in use.

Off-grid routing on the virtual track might cause violations with fractured pin or blockage rectangles.

When virtual tracks are present, the router will use either virtual tracks or regular tracks, depending on which are closest.