It is easy to see from their unique look that the OMAP35x parts have a very unusual footprint. The OMAP35x ball grid array is designed with a 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 methods to correctly route this BGA chip on a PCB in order 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.