High Speed Constraints:
Note: The content in this section is also contained in Part 3 of our Constraint Management Guide.
Min/Max Relative Propagation Delay: Controlling Signal Timing
Definition: Managing the propagation delay of signals to ensure they arrive at their destination at the correct time.
Example: Ensuring that critical signals have minimal delay to synchronize with other signals.
Steps:
To set the signal propagation delay:
1. Go to the following worksheet: Electrical > Routing > Min/Max Propagation Delays.
2. You can create your desired constraint set, but let's look at the existing ones shown below.
3. You can choose the pin pairs (transmitter and receiver) that will be on either side of the signal being propagated through
the respective trace.
4. Choose the Pin Pairs based on your design criteria.
5. Next you can apply the constraint in the worksheet called Net > Routing > Min/Max Propagation Delays
6. Notice that once you apply your constraint set, you can right click on the nets of interest, then choose Analyze, then the
constraint manager will let you know in the Prop Delay columns whether those nets have the actual propagation delays
you need in the board.
IMPORTANT: Please note that you must enable Analysis Mode in Constraint Manager. To ensure this, go to the menu at the top,
Analyze - Analysis Modes. The Analysis Modes window will appear.
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OrCAD X High-Speed Digital Design Guide
