Quartus® Prime Pro Edition User Guide: Design Compilation

ID 683236
Date 7/08/2024
Public

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2.5.1. Identifying Routing Congestion

A global routing congested region refers to an area within the FPGA where the usage of short wires in a specific direction exceeds the region's capacity. A congested net is one that traverses through such congested regions.

To assess congestion, consult the following tools:
  • Global Router Congestion Hotspot Summary Report

    This report shows a high-level, coarse-grained ("global") view of routing utilization taken near the beginning of the routing process when the router works on a coarsened representation of the device floorplan (sometimes referred to as "global routing").

  • Global Router Wire Utilization Map

    This report shows a high-level, coarse-grained("global") view of wire utilization taken near the beginning of the routing process when the router works on a coarsened representation of the device floorplan (sometimes referred to as "global routing").

  • Report Routing Utilization Task in the Chip Planner

    This report shows routing utilization at the end of the routing process.

There is a strong correlation between the routing utilization seen in the initial stages of design routing (as reported by Global Router reports) and the utilization seen in the final stages (as reported by Chip Planner reports). This correlation helps the Global Router reports be effective tools for diagnosing and resolving congestion problems early on, despite any differences in routing utilization that you might observe at various stages of the compilation flow.