Using the Electric VLSI Design System

Chapter II: BASIC EDITING

| ## 4: Circuit Movement |

Components can be moved by clicking on them with the selection button and then dragging them around while keeping the button pressed. During the drag, the new location of the components will be shown, and once the button is released the circuitry will be moved.

Another way to move objects is to use the arrow keys. When a node or arc is selected, each press of an arrow key moves that object by one grid unit. If the menu key is held (Command on Macs, Control on Windows, Meta on UNIX) then the arrow keys move the object by 8 grid units. If you type the letter "h", then subsequent arrow key presses move by only a half of a grid unit (and shifted arrow keys move by 4 units). If you type the letter "q", then subsequent arrow key presses move by only a quarter of a grid unit (and shifted arrow keys move by 2 units). Typing the letter "f" returns to full grid units (with shifted arrows moving by 8).

To move objects along only one line (just horizontally or vertically but not both), use the constrained move button. When editing schematics, this will constrain objects to movement along 45 degree angles. If you wish this to be the default movement operation, check the "Constrained dragging by default" button in the Selection Options... subcommand of the Selection command of the Edit menu. Then, constrained movement will occur with the selection button, and unconstrained moves will occur with the constrained move button.

When arcs are moved by a large amount, they cause the connecting nodes to move with them. However, for small arc motion, the arc may shift within its ports. This can only happen if the port has nonzero area and if the arc has the slidable constraint (shown with the letter "S" when highlighted). These constraints are discussed in greater detail in section 5-2.

Another way to move a node is to use the Get Info command of the Info menu, and type new X and Y positions. The dialog shows the grab-point of the node, which may be in any number of positions (see section 2-2). Note that the default unit for typed values is lambda, unless another unit is explicitly mentioned (for more information on lambda, section 7-2). Note the "Easy to Select" checkbox in this dialog. If you uncheck it, you will have to use the special select button to select the node in the future. This feature allows you to eliminate pieces of circuitry from active editing. |

| If many nodes are selected, the Get Info command will list all of them, and allow position and size changes to be made to each. If a position and size value appears in the dialog, it means that this value is the same on every selected node. If the field is blank, it means that there are different values. Changes are only made in the fields where you type a value. To see the full "Get Info" dialog for the selected node, click on the "Info" button.

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