Step 2: Cut Timing Paths

You can direct the Timing Analyzer to ignore specific signal paths by cutting them from the timing analysis. You can turn on options in the Other Requirements & Options page (Settings dialog box) to cut all instances of specific categories of paths, or you can cut specific paths on a node-by-node basis with the Cut Timing Path assignment in the Assignment Organizer (Assignments menu).

To globally cut off feedback from I/O pins, follow these steps:

  1. In the Settings dialog box, select Other Requirements & Options under Timing Settings. The Other Requirements & Options page appears.

  2. Make sure Cut off feedback from I/O pins is turned on. The Timing Analyzer will now ignore all signal feedback from within the device.

  3. Click OK.


To continue the tutorial, proceed to Section 3: Perform Multiclock Timing Analysis.