Intel® Quartus® Prime Pro Edition User Guide: Design Compilation

ID 683236
Date 12/04/2023
Public
Document Table of Contents
Give Feedback

2.7.2.3.1. Global Router Congestion Hotspot Summary Report

The Global Router Congestion Hotspot Summary report shows congested net hotspots in your design by hierarchical node name.

A global routing congested region is an area of the FPGA where short wire usage in a particular direction exceeds the capacity of that region. A congested net is a net that passes through a congested region.

If the congested area is small, detailed routing can recover by detouring around these overused regions. However, if the congested area is large, you most likely encounter a no route. The exact threshold where that happens varies greatly depending on the design.

Use the Global Router Congestion Hotspot Summary report to identify parts of your RTL code that are associated with routing congestion.

Figure 82. Example of the Global Router Congestion Hotspot Summary Report


Note: In the Number of Congested Nets column, the numerator is the number of nets under the current hierarchical level that overlap with the largest congestion island, and the denominator is the total number of nets under the current hierarchical level (including nets that are not in the congestion island). The largest congestion island is the largest group of adjacent grids whose short wire usage exceeds capacity. You can see a visualization of this report in the Global Router Wire Utilization Map.

The Global Router Wire Utilization Map provides a visualization of the Global Router Congestion Hotspot Summary Report.

If the size of adjacent congested regions is below a threshold, the report shows the threshold and size of the largest congested region instead of a hierarchical report of congested nets.