When you select a constraint type, the corresponding spreadsheet appears in the right subwindow panel. This view lists all existing constraints of that type.
Figure 1. Timing Constraints Categories

Follow these steps to create a new constraint:
- Double-click the name of the target constraint.
- In the dialog box, specify the value for each option.
- Click OK. The tool does the
following:
- Validates the syntax.
- Applies the syntax to memory.
- Adds the new constraint to the end of the spreadsheet.
- Adds the new constraint to the end of the complete constraints list.