Pin Spacing in Abstract Generator

Pin spacing is usually more than line-to-via spacing and less than via-to-via spacing. Start with line-to-via spacing and, if necessary, increase the pin spacing to allow access to both pins by dropping vias (adjacent vias). Normally, the maximum spacing necessary is via-to-via spacing. A single grid pin is a pin with only one port that covers only one grid point.

Use pin spacing so that it is legal to drop vias on all pins, as shown in the following figure.

If you place single grid pins on orthogonally adjacent grid points, you must use via-to-via routing pitch; otherwise, the router might not be able to access the pins.

If you place single grid pins on diagonally adjacent grid points, your routing pitch must be able to accommodate diagonal vias.

Related Topics

Guidelines for Defining Blockages in a Cell Library

Guidelines for Setting Cell Porosity and High Density in a Cell Library