4
Congestion Analysis
Congestion analysis determines the routing capacity of a design. You can run congestion analysis both on globally routed and detail-routed designs. The level of congestion in a design can be represented graphically using a heat map, statistically using a histogram, or by using the routing metrics table that the global routing engine internally uses to map capacity and plan routing.
To simplify the initial problem, the global router creates a course grid that is a multiple of the average of the pitch or routing track grid for the various layers being routed. This course grid is known as the gcell grid. The congestion for every gcell grid is then calculated as the ratio between the number of routed wires and blockages versus the number of available routing tracks.
The Congestion Analysis utility lets you run comprehensive checks and ensure that accurate results are extracted and displayed. It also lets you view and analyze the routing density of a design from initial floorplanning to detailed placement and routing. This data is used to streamline the floorplanning task and let you tune global planning to improve routing convergence, and perform congestion-based pin optimization.
Related Topics
Environment Setup for Congestion Analysis
Displaying the Congestion Analysis Assistant
Loading the Congestion Analysis Workspace
Uses of the Congestion Analysis Assistant
Return to top