Global routing and congestion

Global routing and congestion. Each net is routed as an L across the tile grid and can bend two ways. Every tile a route crosses uses one unit of that tile's track capacity, and a tile overflows when more routes cross it than it can hold.

• No tile over capacity - click a net's route to flip its bend, spreading the routes so the congestion heat map has no red (over-capacity) tiles.

This is the core of global routing: choosing coarse routes so the design is congestion-feasible before detailed routing. Clear the overflow, then Submit design.