Prototyping A Tower

1 of Enlarge image

Freescale MCF5225X Tower

MCF5225X Coldfile board

TWR-SER interface board

I wrote about Freescale's Tower development system when it was first available and I have had one in the lab for awhile. Well, it finally moved to the top of the stack. After working with it I can say that I am as impressed with the overall encounter as I was when I first saw the design.

For those new to the Tower system, it is designed for evaluation and prototyping. The Freescale MCF5225X Tower (Fig. 1) is a good example of the system that normally consists of a processor board plus one or more a peripheral interface boards. They are linked together with a pair of elevator modules that look like backplanes. They are backplanes although these backplanes are designed for peripheral interface distribution.

The Tower boards have edge connections on two sides. They can have connectors on the other two sides. The edge connections plug into PCI Express connectors on the elevator boards.

The elevator boards are not symmetrical and they do not support PCI Express at all. The connectors were chosed because they are cheap, reliable and handle high speed communication. One board is a parallel parallel bus with a little power hardware including a USB connector and power switch. There are two connectors on the opposite/outside of the board where special modules, displays in particular, can be attached.

The other elevator board is simply a PC board with connectors attached. It provides support and rigitidy to the system.

The kit I have includes the MCF5225X Coldfile board (Fig. 2) and the TWR-SER interface board (Fig. 3). The latter has serial and Ethernet connections. The processor board has jumpers, buttons, LEDs and some connectors for debugging but no peripheral connectors. That is what the tower is for.

The approach has advantages for prototypers because a simple two layer board can be designed and plugged into the system. It may not look as slick as some platforms but it is solid, cheap and easy to use.