Using Electric 3-7: Facet Information

Chapter 3: HIERARCHY

| ## 3-7: Facet Information |

### Miscellaneous Commands

The most basic facet information that you can get is a list of facets. This can be done with the Edit Facet... command of the Facets menu. The dialog will show the facet names (at which point you can cancel the dialog).

To get some basic information about the current facet (size, dates, etc) use the Describe this Facet command of the Facets menu.

| To get such information for a subset of facets, use the General Facet Lists... command. The dialog selects a subset of the facets in the current library. The section labeled "Which facets:" selects the facets to be listed (all, only those used in other facets, only those in the current facet, or only "placeholder" facets: those created because of cross-library dependency failures). The section labeled "View filter:" allows only certain views to be displayed. The section labeled "Version filter:" allows removal of older or newer versions of facets. The section labeled "Display ordering:" controls the order in which the selected facets will be listed. The section labeled "Destination:" allows you to dump this listing to a disk file, formatted for spreadsheets (tab-separated).

The last six columns show the usage and five state bits. The usage is the number of times that this facet appears as an instance in other facets. The state bits are: "L" (if the facet contents are locked), "I" (if instances of the facet are locked), "C" (if the facet is part of a cell library), "D" (if the facet has passed design-rule checking), and "N" (if the facet has passed network consistency checking).

To see all exports in the current facet, use the Export menu commands List Exports (for a text listing) or Show Exports (for a graphical indication). To see a list of exports that are electrically connected to the current object, at multiple levels of hierarchy, use the List Exports on Network and List Exports below Network commands from the Info menu.

For more facet information, use the subcommands of the Special Facet Lists submenu of the Facets menu. The List Nodes in this Facet subcommand shows all nonprimitive nodes in the current facet. The List Facet Instances subcommand shows all facet instances below the current facet. The List Facet Usage... subcommand looks up the hierarchy and finds facets that contain the a particular facet as an instance (you will be prompted for the particular facet).

The Graphically, Entire Library subcommand displays a graph of every facet in the library. The Graphically, From Current Facet subcommand displays a graph that places the current facet at the top. These commands create a graph of the facet hierarchy. This graph is actually a new facet, called "FacetStructure", built from Artwork nodes, and stored with the other facets. If you select a name in this graph, then the Edit Facet... command of the Facets menu defaults to that facet. |

The Edit Documentation View command of the View menu allows you to store arbitrary text with the cell. The text editing window that appears can contain any information. See Section 4-10 for more on text editing.

The List Layer Coverage command of the Info menu computes the percentage of the facet that is covered by each layer. This is useful information for certain fabrication processes which insist on a minimum amount of each layer in the die.

### Facet Options

To examine and set more information about existing facets, use the Facet Options... command of the Facets menu:

The upper part of the dialog provides options on a per-facet basis (choose the library and the facet and then set its options). The checkbox "Disallow modification of anything in this facet", allows you to control whether the contents of a facet is editable or not. When modification is disallowed, no changes may be made. This is useful when you want to allow examination without accidental modification. The checkbox "Disallow modification of instances in this facet", also prevents changes to the selected facet, but in this case, only sub-instances are locked. This is useful when you have a correct instance placement and are doing wiring. Buttons on the right allow you to set or clear these flags for all facets.

If you make a change that has been disallowed, a dialog appears that asks if you want to override the lock. You may make the change, disallow the change, or remove the lock (which effectively unchecks the locks in the Facet Options... dialog). |

The check box "Part of a cell-library" indicates that this facet is from a library of standard cells and should be treated accordingly. Buttons on the right allow you to set or clear this flag for all facets. Most dialogs that list facets can remove those from cell-libraries to keep the list simpler.

The "Expand new instances" and "Unexpand new instances" buttons choose whether newly created instances of this facet are expanded (contents visible) or unexpanded (drawn with a black outline) See Section 3-4 for more on expansion.

The "Characteristic Spacing" is the spacing of this facet when arrayed (see Section 6-4).

The lower part of the dialog contains options that will apply to all facets. The check box "Check facet dates during creation" requests that date information be used to ensure a proper circuit building sequence. When this box is checked, warning messages will be issued when editing a facet that has more recent subfacet instances. Electric tracks facet creation and revision dates, and this information can be displayed with the Describe this Facet command and others in the Facets menu.

The check box "Switch technology to match current facet" requests that the current technology automatically change whenever the current facet changes so that the two match.

The check box "Place Facet-Center in new facets" requests that all newly created facets have a Facet-Center node placed at the origin (see Section 3-3 for more on Facet centers).

The check box "Tiny facets hashed out" requests that facets be displayed with a gray hash pattern when they are too tiny for their contents to be distinguished. Without this option, all geometry is drawn, which can take a long time. You can control the threshold of "tinyness" by setting the number of lambda units per pixel. Any view in which this many lambda units are shown in pixel will be too small to display fully.

### The Facet Explorer

The Facet Explorer... command of the Facets menu splits the current window, and shows a hierarchical "explorer" window in the left half. The explorer window has 3 sections: the Contents View, Errors View, and Hierarchical View.

| The Contents View of the facet explorer lists every facet in every library. Inside of each facet is a list of arcs, exports, networks, and nodes. The Hierarchical View of the facet explorer lists only the "top level" facets of each library (top level facets are those that are not used as instances in any other facets). By clicking on the box with the "+", the facet's contents are shown in a recursively indented manner. Each facet lists the number of times that it occurs in the higher-level facet. In both the Contents and Hierarchical View, you can double-click on any object to see it in the other half of the window. Double-clicking on a facet shows that facet. Clicking a facet and typing the DELETE key deletes that facet. Double-clicking on a library name makes that library the current one. In addition, these views have "power buttons" to the right of facet names that open or close every entry underneath them. Any text shown in the Facet Explorer can be copied (and pasted to another document) by selecting a line and using the Copy command.

The third part of the Facet Explorer is the Errors View. This lists all errors that were generated by other tools (DRC, ERC, NCC, etc.) and which are normally presented with the "<" and ">" keys.

The line which separates the Facet Explorer from the edit window can be moved simply by clicking on it and dragging it (see Section 4-3 for more on window control). To make the Facet Explorer go away, delete that window partition, or issue the Facet Explorer... command again.

The font size of text in the Facet Explorer can be set in the "Facet explorer text size" field of the Facet Options... dialog.

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