Using the Electric VLSI Design System

Chapter VI: ADVANCED EDITING

| ## 2: Creation Defaults |

The Duplicate command is useful because a node may have been modified (rotated, scaled, etc.) and duplication preserves all of those changes. Another way to create nodes that are nonstandard is to set creation defaults.

The New Node Options... command of the Info menu provides a dialog for changing this information on subsequently created nodes. You can change the default size of any primitive node in the current technology by choosing the node and changing the values. Note that the default unit for typed values is lambda, unless another unit is explicitly mentioned (for more on lambda, see section 7-2).

The options at the bottom of the dialog apply to all new nodes. You can specify a default orientation (rotation and transposition).

The check box "Disallow modification of locked primitives" requests that all lockable primitive node instances be anchored. Like the facet modification lock, these nodes cannot be created, deleted, or modified in any way while the lock is on. Typically, only primitives in "array" technologies are lockable (such as the FPGA technology, described in section 7-8), presuming that these components will be used to define the fixed circuitry that is then customized. Design of the fixed circuitry can be done with this lock off, and then the customization phase can be done with this lock on.

The check box "Move after Duplicate" allows duplicated objects to be interactively positioned. This is the default condition. However, if this is unchecked, then the Duplicate command of the Edit menu will place a copy automatically, without allowing the new location to be specified by the cursor. This has the advantage that it learns the location to use from past actions, so repeated Duplicate commands can be used to automatically place things correctly.

The check box "Duplicate/Array/Extract copies ports" requests that all node-copying operations also copy their exported ports. This includes the Duplicate and Array commands of the Edit menu and the Extract Facet Instance command of the Facets menu. By default, ports are not copied with their nodes.

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