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19.9 Schematic editing commands

The schematic editing style is an extension of symbolic. In addition to the general, selection, and options editing commands, the following commands are specific to the schematic editing style:

delete-objects			D		[objs] or
[pnts, lines, boxes] ["layer"]
This command takes either an object list created with the select-objects and unselect-objects commands, or points, lines, and boxes with an optional layer-name. The resulting objects are deleted from the cell.

select-major-net				Control-N	
pnts, lines, or boxes
["net name"]
This command finds the net associated with the object under the points, intersecting the lines, or inside the boxes and highlights all objects on that net. If no points, boxes, or lines are specified, the object under the cursor will be examined. Alternatively, if a net name is provided, objects on the named net are highlighted. This command can be used to check the connectivity of a symbolic cell. The command is incremental (i.e. multiple nets can be selected).

move-objects			m		[objs] {pnt pnt}
The move-objects command in schematic editing mode is similar to the same command in physical editing mode above. One difference, however, is that the connectivity of the items moved by this command is not changed. This means an instance moved using this command also causes the segments attached to its terminals to move as well. Moving objects between facets is not supported.

copy-objects			x		(See Below)
The copy-objects command copies a set of objects from one place to another. This command has the same form as move-objects (see above) except that the objects are copied not moved. Like move-objects, the objects copied remain on the argument list for further move and copy operations. However, unlike move-objects, the connections to the objects in the selected set are not copied. Instead, the connectivity between the selected items is copied along with the objects.

create			c		(See Below)
The create command allows the user to add new objects to a schematic cell. Different arguments given to create will produce different objects.

Formal Terminals - "terminal-name [type] [direction]" : create

When create is given a single argument string, the name of a new formal terminal, a formal terminal is created. The implementation of the formal terminal is taken to be the actual terminal currently under the mouse (note: a connector terminal can also be used for this purpose). Since terminals in schematic may be quite small, this routine will try to find nearby terminals if it doesn't find a terminal directly beneath the cursor.

Formal terminal names must be unique within the cell. If a formal terminal of the given name already exists, vem will display a dialog box asking whether or not you wish to replace the old terminal.

Two optional pieces of annotation can be placed on the terminal: type and direction. The type can be one of SIGNAL, CLOCK, GROUND, SUPPLY, or TRISTATE. If not provided, SIGNAL will be assumed. The direction can be one of IN, OUT, or INOUT. If not specified, INOUT will be assumed. If either of these values are not provided in the terminal name specification, vem will post a dialog box containing fields for entering both the terminal type and direction. Pressing the left mouse button in the value area for these fields will cause a menu of the possible choices to appear. New values can be selected by releasing the mouse button over the desired value. Once appropriate values are selected, activating the Ok button at the bottom of the dialog will save the annotations. Activating the Dismiss option will leave the annotations unspecified. These annotations can be edited later using the edit-property command.

Instances - pnts [[master:view] [instance-name] : create

If the arguments to create are a number of points followed by an optional string, instances will be created with their origins at those points. If the name of the master is not specified textually, it will be inferred from the instance under the mouse.

The string argument has two parts: the instance specification and name. Both of these fields are optional. Specifying a null string is considered to be the same as no string at all. The instance specification is a master-view pair, such as "amp:schematic". If this field is left out, the master is inferred from the instance under the mouse. Otherwise, an attempt is made to locate the instance by the master-view pair. If the name field is given, the instance will be given the specified name.

NOTES: Newly created instances whose actual terminals intersect actual terminals of other instances will be automatically connected. In this case, no path is required between the terminals. Rotated and mirrored forms of instances can be created by instantiating a new instance and using the transform and move-objects or transform and copy-objects commands.

Paths - lines : create

This command creates new segments for connecting together instance actual terminals. A new series of segments will be created on a predefined layer (WIRING). Connector instances will be placed automatically at all jog points. The width of the new path is always zero.

Normally, the schematic editing style has a feature turned on called "gravity". When you draw segments with gravity turned on, vem will try to connect the segments to a nearby terminal if you miss a terminal by a small amount. This is useful when editing a large cell.

edit-label			E		[pnt] {"layer"} or [objs]
The edit-label command creates and edits labels, and is identical to the version in physical editing mode, documented above.

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