In electrical mode, the Add button brings up a menu of property types that can be added. Selecting an entry will initiate prompting for the associated string. Any selection in the listing will be ignored. Unlike the case of the Edit button, the arrow keys and subsequent selection in the listing will not affect the prompt line.
With the Global button off, completion of editing by pressing Enter will ``add'' the new property to the current object. In electrical mode, properties other than the other property will be replaced if they exist, since there can be at most one such property. There can be arbitrarily many other properties, or properties of any number in physical mode. Such properties are always added and not replaced.
If the Global button is active, an identical copy of the property will be added to each of the devices in the internal list. This will be a replacement for electrical properties other than other, and an addition otherwise. Unlike the Edit button case, there is no individual prompting for a string for each device. The initial string (and number, in the case of physical mode) is added to each object.
In electrical mode, the Add menu contains buttons for the modifiable device properties. The Name button allows the modification of a name property. The name property specifies the device name to SPICE. Unlike the other user settable properties, the name property always exists. if not explicitly set by the user, the device name will be generated internally. However, if a correspondence to an existing SPICE file is necessary, the name must be specified. Xic allows any name, however for the device to be recognized by SPICE, the name must start with the device's key letter as expected by SPICE. Deleting the name property simply reverts back to the internally generated name.
If an assigned name property conflicts with an internally generated name, the internally generated name will be updated so as to not conflict by appending ``_N'', where N is some integer.
The Model, Value and Param buttons allow addition of a model, value or param property, respectively. Only one of model or value properties should be used per device, as this really represents two different names for the same text field in SPICE output. One has the choice a supplying a device model or component value to the device, but not both. The param property is a catch-all for additional parameters found in the device line in SPICE, such as initial conditions or device geometrical factors.
The NoPhys button allows addition of a nophys property. This property does not affect SPICE output, but specifies that the device or subcircuit has no physical implementation. When Xic is associating physical and electrical objects for extraction and LVS, a physical implementation will not be sought for objects with this property.
When the property is created, the user is prompted as to whether the device terminals should be shorted together during LVS. Devices that have the nophys property applied will be rendered using a different color than ``normal'' devices. See the description of LVS in 13.16 for a more complete discussion of the use of this property.
The NoSymb button is used to add a property to electrical subcircuit instances which forces them to be displayed as expanded, whether of not the master cell of the instance is symbolic. Instances with this property will behave in all respects as if the master were non-symbolic. Thus, instances of the same master can be displayed symbolically or not, in the same design. This property uses the same property number as the symbolic property applied to cells.
There can be at most one each of the properties described above. This is enforced by Xic, i.e., attempts to add a second property of a given type will cause replacement, not addition.
The Other button allows addition of an other property. These properties have no significance to Xic and are not used in SPICE output. They can be used to store alternate values for the model, value, or param properties, or to store any other information desired by the user. There can be arbitrarily many other properties per device.