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Tutorial: Managing Signal Integrity Analysis Results with User Directed Groups in OrCAD

A Directed Group is a component-based selection of nets, allowing you to select an entire interface based on component connectivity rather than net name. By using a Directed Group in your analysis, you can view the results for a collection of nets progressing along the same time-line. This helps you prioritize issues in your design; for example, issues found near the starting point versus issues found near the ending point. Focus your attention on known problem areas by performing the analysis on a portion of the net (between two desired components) rather than simulating the entire net.

Step 1: Set the Analysis Mode to “Directed Groups” and click Select Directed Groups in the Workflow Manager.

This will bring up the dialog box to select, create or modify directed groups.


Step 2: Create a Directed Group.

Select a starting component from the list in the Start Component box. This will automatically create a list of the valid ending components in the End Component box.

Select an ending component from the list in the End Component box.

Step 3: Preview and Create the Directed Group.

Select the desired nets in the Directed Group Creation Preview Window. By default, all nets are selected.

When the desired nets have been selected, click Create. The Directed Group is created and can be viewed in the Directed Group Selection Window.

Note: By default, the created directed group is automatically selected for analysis.

Click Apply and click OK.


Step 4: Continue with the Analysis.

Click Start Analysis in the Workflow Manager.


Step 5:  View the results for the Directed Group. 

Under View Modes select “Directed Group”.


Step 6: Click on the plot to view the results.

View specific nets by using the selection window on the left or view simulation results for all nets in the directed group. By default, all nets are selected.