Creating a Snap Boundary

A snap boundary is used for designs that implement any rectilinear macros or standard cells. A snap boundary must be a rectangle. Placement tools use the snap boundary to place instances of the design in rows, thereby aligning the snap boundary origin with the site origin. If the PR boundary is a rectangle, no snap boundary is needed. You may need a snap boundary for cells with rectilinear (but non-rectangular) PR boundaries. Only one snap boundary is allowed per cellview.

To create a snap boundary:

1. In the layout window, choose Create – P&R Objects – Snap Boundary.
2. Press F3 to open the Create Snap Boundary form.
3. Select Create as ROD Object if you want to create the snap boundary as a ROD object. The Name field becomes editable, allowing you to change the name from the default.
4. From Create Method choose a method and create the snap boundary.
   • From Selected Set
     Select From Selected Set. Then, select objects on the canvas to add to the selected set. Once you have selected the objects, click the Apply button in the form to create the snap boundary.
   • Rectangle
     Select Rectangle. Then, specify a rectangle area on the canvas for the snap boundary. The Apply button field is grayed out when using this method.

Related Topics

Create Snap Boundary Form