The sea-of-gates router is able to take an arbitrary set of unrouted arcs and convert them to layout.

To do this, use the Sea-Of-Gates Route this Cell command (in menu Tools / Routing). If there are unrouted arcs selected, these will be the only ones converted. Otherwise, all unrouted arcs in the cell will be converted. If sub-cells below the current cell need to be routed, use Sea-of-Gates Route Sub-Cells.

The router has many features that can be controlled by the Routing Preferences and by cell-specific properties.

Routing Preferences

The Routing Preferences (in menu File / Preferences..., "Tools" section, "Routing" tab) has these options:

Cell Properties

Users can set cell-specific properties that control how a particular cell is routed. Use the Sea-Of-Gates Cell Properties... command in the Tools / Routing menu to control this. The upper part of the dialog controls routing properties for the entire cell.
  • Horizontal/Vertical Layer Properties controls the placement of alternating layers for horizontal and vertical wires. You can choose whether odd-numbered arcs are horizontal or vertical. You can also choose to ignore the alternating layers requirement.
  • Do not make Steiner Trees (already done) Before routing begins, the unrouted arcs are reorganized so that daisy-chains (multiple arcs on a single network that connect more than two ports) run in the most efficient way. This efficient path is called a "Steiner Tree". If you believe that the routes are already optimized, you can request that this step be skipped.
Figure 9.69

The lower part of the dialog controls individual layers in the cell. It lets you disable the use of any layer, or favor it above others. It also lets you set a grid for placement of the layer.