Contact

Connecting Cell pins to a metal bus, using the SkillCAD V-Editor, Bus Connect application.

When routing metals at higher levels of hierarchy, the layout designer will often combine many metals (signal wires) into a bus for efficient routing.  The signal wires in the bus may go to many different circuit blocks.  The circuit blocks will usually have the internal routing, that goes out of the block, routed to the edge of the block with a pin (port) on the circuit block edge.

As the bus is routed by the circuit block, the designer needs to connect metal from the pin, on the edge of the circuit block, to the correct signal metal in the bus.  Usually the layout designer has to find the pin on the circuit block edge, then find the correct signal metal in the bus.  The designer then has to set the correct metal layer for the pin, select the wire command, and enter the points for the metal wire from the circuit block pin to the correct signal metal in the bus, set the wire width to match the pin width, and select the correct via to connect to the signal wire.  This process is repeated over and over again, until all the pins on the circuit block that goes to the signal metals in the bus are connected.  The more pins, the longer it takes.  Flight lines from the circuit block pin to the correct signal metal make this process a little easier.  But it is still a very manual process.

Using the SkillCAD, V-Editor, Bus Connect application, makes this whole process as simple as drawing two selection lines.  One line, drawn across the pins, selects the pins on the edge of the circuit cell block.  The other line, drawn across the signal metals in the bus, selects the metals that connect to the pins.  Based on the Virtuoso XL connectivity, the application automatically matches the metal widths to the pin widths, sets the correct metal layer for each pin, and connects all the pins to the correct signal metals, with the correct vias.  Connecting one pin or a hundred pins can be accomplished with just the two selection lines.

Video: V-Editor Bus Connect, Connect Pins to Bus Metals