The routing tool contains a number of different subsystems for creating wires. Two stitching routers can be used in array-based design to connect adjoining cells. A maze-router runs individual wires. A river-router is available for running multiple parallel wires. The sea-of-gates router handles many wires in arbitrary connection situations. The clock-router builds balanced trees that guarantee constant-length paths to each destination cell. Finally, there are six experimental routers, based on the A* and the Lee/Moore algorithms.
All of the non-stitching routers make use of the "Unrouted Arc", a thin-line arc that can connect any two components. Creating "rats nests" of these arcs forms a graphical specification that the router can use. The unrouted arc is from the Generic Technology (see Section 7-6-3). To create one, use the Get Unrouted Wire command (in menu Tools / Routing). | ![]() |
Then use standard wiring commands to run the unrouted arc. Another way to get unrouted wires is to select all or part of an existing route (made with any arc) and use the Unroute Network or Unroute Segment commands. Unroute Network replaces all arcs on the selected network whereas Unroute Segment only removes the selected segment of the network that runs between termination or forking points.
Another way to get Unrouted arcs for router input is to use the Copy Routing Topology and Paste Routing Topology commands. These copy the network topology from one cell (the "copied" cell) to another cell (the "pasted" cell). The copied cell should be properly routed. The Paste Routing Topology command uses node and arc names to associate the two cells.