The user draws the four sides and the inner in a cell with Layout: $PadFrame. One to four corners may also be present. The four sides are regular objects, typically produced by abutting pads. The AttributeProc interprets the following properties, attached as object satellites of this cell. Default values are shown if the property is not mandatory; all dimensions in lambdas.

The four sides, corners (if present) and the inner are expected to be positionned properly in the schematics. The layout of the top and bottom sides are expected to match in width; similarly, left and right in height.

The direction of metal applies inside the power routing, close to the inner. If you specify "metal2" for example, vertical wires will leave the inner in metal2, and horizontal wires in metal. Notice that there is an inversion of material when wires go through the power region.

The external channel is used only to scoot over signal pins from the pads which face pins in the power area: a few tracks usually suffice.

The size of the power region determines the size of the power buses. If both padframe and inner have multiple power pins, the buses can be quite thin, otherwise they can be a fraction of a mm wide. No tool is available today to determine this size, so it is a designer's decision. Typically, fill-up any leftover space with power buses, and check that they are sufficiently wide.

The inner is normally centered inside the cavity, but can be manually adjusted with innerDX and innerDY to balance the size of routing around it. Sorry for the lack of automation, but it is a hard problem.

There is a little switchbox in all four corners which can get very crowded if there are too many pins on the sides on the corners. The idea is to extend the top and bottom sides by an amount equal to outerWidth (1/2 on each side), so that the switchboxes have pins only on the left or right. For all circuits of the Dynabus family, designers should extend the top and bottom sides by 90m on each side, so that all circuits have identical pad frames. This can be done graphically with Layout: $Extend, Left: 90, Right: 90. Circuits which have few or no pins near the corners can ignore this parameter and save area.