Congestion Analysis Toolbar

Lets you access the main functions with a single mouse click.

Customizable Histogram

Lets you illustrate and customize the congestion results in the design based on the selected filter option.

Global Cell Track Utilization Table

Provides the capacity and availability information of every global cell (gcell) in the design.

Net Selection Table

Displays the nets passing through the gcell selected in the Global Cell Track Utilization table.

Congestion Analyze

Runs different methods of congestion analysis on the design.

Global Route and Congestion Analysis

Runs global routing to build the gcell grid, run four passes of global routing on all nets, and then runs congestion analysis to build the histogram, create the heat map, and populate the global cell track utilization table. This is the default mode

Global Route and ECO Congestion Analysis

Runs global routing in ECO mode, which means that global routing is run on the nets for which the global bias constraint has been created. It then runs congestion analysis to update histogram, heat map and the global cell track utilization table.

Global Route and Ignore Penalty Congestion Analysis

A special what-if analysis mode for early floor planning. It runs global routing, where each net takes the shortest possible path regardless of other nets. This lets you evaluate if the floorplan is underutilized and if it can be compacted early in the design cycle or highlight the most common regions of over-congestion to indicate that more space might be required.

After global routing, it runs congestion analysis to update the histogram, the heat map, and the global cell track utilization table.

Congestion Analysis

Runs only congestion analysis on the design to build the histogram, create the heat map, and populate the global cell track utilization table based on the previously routed data. This mode is useful when you already have a fully detail routed design and you want to save the run time.

Options

Opens the Congestion Analysis subform in the Virtuoso Space-based Router Options form.

Clear Congestion Analysis Data

Clears the congestion analysis results and removes global routing.

Zoom Selected Global Cells

Lets you zoom to selected global cells or nets.

Filter Global Cells By

Provides options to filter and display congestion data.

All Layers without Filters

Resets any filters that have been applied.

Define Area

Lets you draw a box in the main window to filter an area of the design to display congestion analysis. The heat map, histogram, and global cell track utilization table are updated to only show the congestion data within the defined area.

Show Selected Global Net Edges

Highlights the selected nets in the heat map. Also, the histogram and the global cell track utilization table are updated to show the congestion data of only the selected nets.

All Layers Average Congestion

Calculates the average congestion for all horizontal and vertical layers in a design.

Used Layers Average Congestion

Calculates the average congestion for only the horizontal or vertical layers that have been routed in a design.

Maximum Congestion

Calculates the maximum congestion for all horizontal and vertical layers in a design. This is the default congestion analysis mode.

Show Unusable Global Cells

Enables the display of the global cells that are blocked and are essentially not available for any global paths or interactive routing.

Environment variable: cmapShowUnusedGCellMode

Congestion Map Visible

Toggles the display of the existing congestion map.

Show Empty Global Cells Only

Displays all gcells that have zero congestion in the heat map and histogram.

Layer Display

Lets you choose specific layers when calculating and displaying congestion in the heat map, histogram, and global cell track utilization table.

Congestion Histogram Customize

Lets you filter the histogram to display specific buckets of congestion.

Environment variable: cmapHistogramRanges

Global Bias Setup

Lets you create, modify, and delete global bias constraints that can be used to plan the routing of a net group.

Finish with Detailed Routing

Starts Virtuoso Space-based Router to complete detailed routing of the selected set of nets or the entire design.

Route All Nets

Routes all nets using the standard VSR routing flow.

Route Selected Nets

Routes only the selected nets using the standard VSR routing flow.

Cell Index

An internal numbering system for all the gcells in a design.

Layer

A layer of the gcell for which the track utilization data is displayed.

Used Blockages

The number of tracks used by blockages for the specified layer of the gcell.

Used Pre Routes

The number of tracks used by pre-routed nets for the specified layer of the gcell.

Used Global Routes

The number of tracks used by globally routed nets for the specified layer of the gcell.

Available

The number of tracks that are not used for the specified layer of the gcell. The information in this column is based on a simple calculation.

Available = Gcell Total Tracks – Used Blockages – Used Pre Routes – Used Global Routes

Gcell Total Tracks

The total number of tracks for the specified layer of the gcell.

Net

Displays the nets passing through the selected gcell.

Number Cell Occupied

Displays the numbers of cells occupied.

Selected Color

Displays the color selected for the net.