Via minimization

Via minimization. Routing is preferred-direction: horizontal runs go on one metal layer and vertical runs on another, so every turn in the wire is a via (a layer change), and vias cost resistance and yield.

• Source connected to target - lay wire from S to T.
• Vias within budget - the route's via count is the fewest turns a path through your wire takes. Favour long straight runs; a wiggly shortest path racks up vias, while a slightly longer, straighter route uses fewer.

Route it with few vias, then Submit design.