It is easy to see from the unique look that the OMAP35x parts have a very unusual footprint. The OMAP35x ball grid array is designed with new technology called the Via Channel™ array, which makes significant printed circuit board (PCB) cost savings possible. If the PCB is routed correctly, this cost savings can be substantial. This application report explains how this is possible and shows several methods in which this can be done.
This document will explain methods to correctly route this BGA chip on a printed circuit board to take advantage of the features of the Via Channel array. It also shows how to route the entire OMAP35x chip in only two signal layers, using cheap PCB technology rules.
For more information regarding routing an OMAP35x system, see the SDRAM Controller Subsystem (SDRC) section in the device data sheet.