Creating Instances

An instance is a database object that represents a master cellview. You can have several instances of the same cellview in a design. Use the Create Instance command to place an instance of a cell into the current cellview.

By default, the layout editor automatically assigns names to instances, starting with the first instance as I1 and continuing with I2, I3, and so forth. If the instances are mosaics, the default names are M1, M2, and so forth. If you override the assigned name, the first name in the form is assigned to the first instance you place. The next name is assigned to the next instance you place, and so forth. You can use the Display Options form to display instance names in the cellview.

In case the design has Embedded Module Hierarchy (EMH), you can specify the complete hierarchical path name, starting from the top module to the new instance to be created using the hierarchy delimiter in CDB name space, for specifying the location in EMH where the instance is to be created. An example of such a name is modA‘modB‘15, where A and B are the names of the module instances and 15 is the name of the newly created instance.

To place a cell inside the current cellview:

1. In the layout window, choose Create – Instance or click the Create Instance icon on the Create toolbar.
   Alternatively, right-click at any free space on the design canvas to display the Layout shortcut menu and select Create – Instance.
   The Create Instance form appears.
2. Fill out the Library, Cell, and View fields to specify the name of the master cell you want to place as an instance in the cellview.
3. To override the automatic naming of instances, type one or more instance names in the Names field, leaving a space between names.
   Do not use the character forward slash (/) in instances names. If used, it gets replaced with its octal representation #2f. Therefore, do not use a name such as I1/I2 for an instance.
4. Select the Physical Only check box to create the instance in such a way such that it exists only in the block domain and not in the module domain.
5. Optionally, you can create a mosaic or array of instances by typing values in the Rows and Columns fields in the Mosaic section.
6. To change the spacing between the rows or columns, type values for Delta Y,X.
   By default, the fields are set to the width and length of the original cell, so that the edges of each instance touch but do not overlap.
7. To rotate the instance, use the Rotate Left or Rotate Right icons in the form, or click the middle mouse button as you place the instance.
8. To mirror the instance, use the Flip Vertically or Flip Horizontally icons in the form. Alternatively, as you place the instance, press Ctrl and click the middle mouse button to mirror the instance horizontally or press Shift and click the middle mouse button to mirror the instance vertically.
9. Click on the canvas to place the instance. Alternatively, you can specify the points where you want to place the instance using the Enter Points form.

If you specify the Description field in the Edit CDF form for a cell with Component Description Format (CDF) parameters, the description is displayed as a tooltip on the mouse over of that field.

Related Topics

Create Instance Form

Enter Points Form

Edit CDF Form

Display Options Form

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