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Ports |
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To export a port, select a port on a node and use the Create Port... command of the Port menu. The resulting dialog requests a port name and some characteristics. All port names on a facet must be unique; if a nonunique name is given, it is modified (by adding "-1", "-2", and so on) to be unique. Like facet names, port names may not contain spaces, tabs, or unprintable characters, and no case distinction is made between uppercase and lowercase characters. | ![]() |
Behavioral characteristics can be associated with a port by selecting the appropriate field in the port creation dialog. These behavior characteristics are stored with the port and used primarily by simulators.
The "Always drawn" check box requests that the port label should always appear, regardless of the connection or expansion of its facet. Typically, a port label on an instance of a facet is not displayed when that port is connected to an arc or when the instance is expanded. This check box overrides the suppression.
Another special check box, "Body only," requests that this port not appear when an icon is generated for the facet. This is useful for power and ground ports or duplicate connection sites on a single network.
Once a port has been exported, the characteristics can be modified by selecting the port name and using the Get Info command of the Info menu. In addition to allowing the port name and characteristics to be changed, the dialog allows the size and placement of the port text to be modified. | ![]() |
Another possible change to a port is to unexport it. The Delete Port command of the Port menu removes the exported ports on the currently highlighted node. Arcs are deleted if they connect to formerly exported ports on instances of the facet higher in the hierarchy.
It is sometimes desirable to keep an exported port but to transfer it to another node. If a facet is in use higher in the hierarchy, unexporting and then reexporting deletes all existing connections. Instead, the Move Port command of the Port menu can be used. Before using this command, two nodes and their ports must be highlighted with selection button and toggle select button. The exported port is moved from the first node to the second node.
There are two special port exporting commands that are primarily used in array-based layout. If a facet instance is replicated many times and the instances are wired together, then ports on the edge of the array are the only ones that are not wired. These ports define the connections for the next level of hierarchy. What you want to do is to export all unwired ports on all facet instances. To do this, use the Re-Export Everything command of the Port menu, which generates unique port names as it exports all unwired ports on facet instances. To do this same function, but only in the currently highlighted area, use Re-Export Highlighted. Note that ports on primitive nodes are not exported with these commands. See the Array command of the Edit menu for array generation, and see the "stitching" options of the Routing command in the Tools menu for automatic wiring.
Finally, it is possible to control how ports are displayed on the screen. The Port Display command of the Windows menu provides four options: "Full Port Names" shows full text names, "Short Port Names" shows port names only up to the first nonalphabetic character, "Ports as Crosses" shows crosses at the port locations, and "No Ports Shown" indicates that no ports are to be displayed. With short port names, the ports "Power-left" and "Power-1" are both written as "Power," which allows multiple ports with the same functionality but different names to be displayed as if they have the same name. | ![]() |
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