Intel® Quartus® Prime Standard Edition User Guide: Design Optimization

ID 683230
Date 11/12/2018
Document Table of Contents

5.1.5. Viewing Routing Congestion

The Report Routing Utilization task allows you to determine the percentage of routing resources in use following a compilation. This feature can identify zones with lack of routing resources, helping you to make design changes to meet routing congestion design requirements.

To view the routing congestion in the Chip Planner:

  1. In the Tasks pane, double-click the Report Routing Utilization command to launch the Report Routing Utilization dialog box.
  2. Click Preview in the Report Routing Utilization dialog box to preview the default congestion display.
  3. Change the Routing Utilization Type to display congestion for specific resources.
    The default display uses dark blue for 0% congestion (blue indicates zero utilization) and red for 100%. You can adjust the slider for Threshold percentage to change the congestion threshold level.

The congestion map helps you determine whether you can modify the floorplan, or modify the RTL to reduce routing congestion. Consider:

  • The routing congestion map uses the color and shading of logic resources to indicate relative resource utilization; darker shading represents a greater utilization of routing resources. Areas where routing utilization exceeds the threshold value that you specify in the Report Routing Utilization dialog box appear in red.
  • To identify a lack of routing resources, you must investigate each routing interconnect type separately by selecting each interconnect type in turn in the Routing Utilization Settings dialog box.
  • The Compiler's messages contain information about average and peak interconnect usage. Peak interconnect usage over 75%, or average interconnect usage over 60%, can indicate difficulties fitting your design. Similarly, peak interconnect usage over 90%, or average interconnect usage over 75%, show increased chances of not getting a valid fit.