Using the Electric VLSI Design System

Chapter III: HIERARCHY

| ## 11: Facet Views |

### Setting a Facet's View

All facets have views, which provide a description of their contents. A view consists of a full name and an abbreviation to be used in facet naming. For example, the "layout" view is abbreviated "lay" and so the layout view of cell "adder" is called "adder{lay}." When no view name appears, the facet has the "unknown" view. Possible views are:

- "layout" (for IC layout)
- "schematic" (for logic designs)
- "schematic-page-N" (for multipage schematics)
- "icon" (to describe a facet symbolically)
- "simulation-output" (used by SPICE simulation)
- "skeleton" (a minimal view)
- "documentation" (a text-only view)
- "VHDL" or "Verilog" (text-only views for hardware-description language editing)
- a number of "netlist" views (text-only views that list connectivity for various tools such as "netlisp", "als", "quisc", "rsim", and "silos")
- "unknown" (no specified view)

When creating a facet with the Edit Facet... command, you can specify its view in the "New Facet" subdialog. After creation, you can change the current facet's view with the Change Facet's View... command of the View menu. Note that this is one of the few commands in Electric that is NOT undoable. |

### Switching between Views of a Facet

When editing one view of a cell, there are a set of commands in the View menu that will switch to an alternate view of the same cell. Use Edit Layout View to switch to the layout view, Edit Schematic View to switch to the unnumbered schematic view, Edit Multi-Page Schematic View... to switch to a particular page of a multipage schematic (this is the only command that can create new pages of a multipage schematic), and Edit VHDL View... to switch to the VHDL view. For all other view types, use Edit Other View and select the desired view. Note that these commands are equivalent to the Edit Facet... command of the Facets menu with an appropriate selection.

When editing facets with text-only views, the window becomes a text editor. You may then use the Write Text Facet... and Read Text Facet... commands of the Facets menu to save and restore this text to disk. See section 4-10 for more on text editing.

### Creating and Deleting Views

If the list of possible views is not sufficient to describe a facet, new views can be created with the New View Type... command of the View menu. This command requests a name and an abbreviation. Generally, an abbreviation should be the first few letters of the full view name. This abbreviation will be used when describing facets with that view. For example, the view "fast-layout" might have the abbreviation "fast". The "Textual View" checkbox indicates that this is a text-only view, like "Documentation", "Netlist", and "VHDL". |

To delete a view, use the Delete View Type... command of the View menu. You can only delete views that you have created, not the basic views that exist on startup (such as "layout", "schematic", etc). Also, there must be no facets with the view that is being deleted.

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