Using the Electric VLSI Design System

Chapter VI: ADVANCED EDITING

| ## 10: Outline Editing |

### What is an Outline?

For some primitive nodes, it is not enough to rotate, mirror, and scale. These primitives can to be augmented with an outline, which is a polygonal description. The Outline Edit command of the Edit menu is used to create, delete, and move individual points in a node's outline.

There are quite a few primitive nodes that make use of outline information. The MOS transistors use the outline to define the gate path in serpentine configurations (see section 7-4). Also, all of the pure-layer nodes in the IC layout technologies are precisely defined with the outline. The pure-layer nodes are those in the New Pure-Layer Node command of the Edit menu (see section 7-1). For example, the node called "Metal-1-Node" in the CMOS technologies looks like a rectangle of the Metal-1, until you add outline information. With an outline, this node can take any shape. Finally, the Artwork technology has nodes that use outline information: Opened-Solid-Polygon, Opened-Dotted-Polygon, Opened-Dashed-Polygon, Opened-FarDotted-Polygon, Closed-Polygon, Filled-Polygon, and Spline (see section 7-7).

### Manipulating Outlines

To manipulate outline information on the currently highlighted node, use the Outline Edit command of the Edit menu. After issuing this command, the selection button is used to select and move a point on the outline, and the creation button adds a new point after the selected one. You can also use the left and right arrow keys to move around the outline. Use the Erase command of the Edit menu (or the Delete key) to delete the highlighted outline point. The Rotate and Mirror commands of the Edit menu change to Rotate about Point and Mirror about Point which allow the entire node to pivot about the currently selected point. Finally, the Get Info command of the Info menu changes to Get Outline Info and displays a dialog which allows precise manipulation of the data. |

When done editing the outline, use the Exit Outline Edit command (in the same location as Outline Edit was in the Edit menu).

### Special Outline Generation

| To generate a doughnut shaped outline, use the Annular Ring subcommand of the New Special Object command of the Edit menu. This dialog prompts for a layer to use and an inner and outer radius for the annulus. By default, it is made as a full circle (360 degrees), but this can also be changed. Finally, the number of line segments used in the construction can be set, allowing for smoother or coarser shapes.

To generate text-shaped outline, use the Text (layout)... subcommand of the New Special Object command of the Edit menu. This dialog prompts for a layer to use, the font size, and text. The scaling factor can make arbitrarily large text. |

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