Hi Jerry,
One really good trick is how to hook a logic analyzer to those itty-bitty balls on the processor. Back when I was a boy, processors had 40 legs and no balls. :-D You must have a board with a logic analyzer connector.
Thankfully the Freescale MDS boards do have logic analyzer headers on their boards.
My custom boards have 5000+ BGA balls ....
http://www.ovro.caltech.edu/~dwh/carma_board/
so I made sure to hang a few logic analyzer connectors on that too :)
One interesting thing that came out of the board development is that the PowerPC processor was RoHS, while the FPGAs were not. The assembly company stripped the RoHS balls off the PowerPC, reballed them non-RoHS, and then assembled the boards. The boards were then X-rayed with what amounts to a CT scanner, and each ball shape was observed at the bottom, middle, and top to ensure that they all looked nice and pretty.
Amazing stuff :)
Cheers, Dave