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The Info Button: Display Information About Objects

The Info button in the View Menu brings up a an Info window, which can display information about the current cell or any visible object. This command can also facilitate pushing the editing context to specific locations within the hierarchy.

Alternatively, if any objects are selected when the command is given, information about all selected objects can be dumped to a file. When the command is entered, if there are selected objects, the user is prompted whether to dump the info to a file. If `y' is given to the prompt, the user is asked for a file name, and is given the option of viewing the file when the dump is complete.

If there is no prompt, or `n' is given at the prompt, any selected objects become deselected, and ``info mode'' becomes active. Objects and unexpanded subcells can be clicked on, and information about an object will be displayed in the text window that will appear. The chosen object will be highlighted in the display.

Although the clicking/highlighting operation is superficially similar to normal selection, in fact there are important differences. However, the layer selectability and object type selectability flags for normal selections are observed.

  1. Any object or unexpanded subcell visible in the drawing window can be chosen, at any depth in the cell hierarchy. In normal selection, only objects and subcells of the current cell can be selected. The ``selection'' mechanism tracks the expansion depth of the display window, including peek mode if active (see 12.4). Any object that is visible, or any subcell that is shown as unexpanded, can be chosen by clicking on the object in the window.

  2. Only one object or unexpanded subcell can be highlighted at a time. This is the item whose information is shown in the window. To highlight a different object at the same location, click multiple times. A different object will be highlighted on each click.

The information shown in the window will include the name of the cell that contains the chosen object, and a ``back trace'' of containing subcells in the hierarchy up to the current cell. Thus, one can easily determine the cell which ``owns'' an object in the display.

While an object is selected, pressing Enter will toggle selection of all or other objects in the cell containing the original selected object. The objects selected will respect the settings of layer-specific selection mode, and object type selectability, as set in the Selection Control Panel. In this state, the text in the Info window will describe the instance containing the selected objects. Pressing Enter again will revert to the previous state. This is useful for determining which objects belong to a particular cell instance.

When an object is highlighted, initiating the Push command in the Cell Menu will push the editing context to the cell containing the chosen object. That is, the current cell becomes the cell containing the object, in the context of the instance in the chosen location. The objects in this cell can then be edited. The Pop command in the Cell Menu can be used to pop the editing context back up the hierarchy to the original current cell. This can be a useful way to navigate through a complex hierarchy, while editing a layout.

If the Shift key is held while the user clicks anywhere in a drawing window showing the current cell, or if the click occurs outside of the current cell bounding box, information about the current cell is shown, rather than information about a chosen object.

If the user clicks in a sub-window that is displaying a cell that is not the current cell, information about the cell will be shown. It is not possible to select objects in this case.

The information shown in the text window contains items such as the object type and bounding box, as well as details specific to the type of object. For objects not in the current cell, coordinates are usually shown relative to the object's containing cell, as well as those reflected to the current cell.

By default, dimensions are given in microns. If the variable InfoInternal is set (with the !set command) then dimensions are given in internal units (usually 1000 units per micron).

The text window contains two buttons. The Dismiss button removes the pop-up and exits info mode. The Activate button, which is initially active, can be used to exit and reenter info mode, while the pop-up remains visible.

When applied to polygons, the Info command performs reentrancy tests, and a message is added if the condition is found, i.e., if the polygon can not be rendered unambiguously.

Similarly, when applied to wires, the wire is checked for certain properties that might cause trouble. See the description of the !wirecheck command in 19.14.13 for a description of the flag keywords that might appear in the info text.

The Info pop-up is also made visible by the Info button in the Cells Listing panel brought up by the Cells List button in the Cell Menu. When this button is used, previously selected objects are ignored, and there is no provision for dumping to a file. The Info window will provide information on cells selected in the cells listing, or on objects selected in the drawing windows.

next up previous contents index
Next: The Allocation Button: Show Up: The View Menu: Alter Previous: The Rulers Button: Create   Contents   Index
Stephen R. Whiteley 2022-05-28