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Prototyping board supports direct 8-32bit MCU upgrade

PCB links to compatible boards for rapid prototyping and MCU evaluation

26th June 2007 - Engineers contemplating moving from 8-bit to the 32-bit microcontroller systems now have a new option in the shape of Freescale's Flexis MCU chips. Two chips released to introduce the Flexis range provide, respectively, 8- and 32-bit devices that are not only software- and peripheral-compatible, but pin-for-pin compatible to permit a direct upgrade. MC9S08QE128 is the 8-bit part, and MCF51QE128 the 32-bit, Coldfire architecture, chip. Software you write for the 8-bit part will run unmodified on the 32-bit.
Supporting the Freescale parts at launch is the Crossbow development board from distributor Future Electronics. Crossbow conforms to the company’s Future-Blox format: this is a common mechanical and electrical design that the distributor created to promote easy adoption of products it supplies from a variety of manufacturers. Future-Blox boards host active devices in a range of typical configurations in a stackable interconnection format, allowing you to rapidly prototype a complete system. Boards previously released include Ethernet embedded controllers, a brushless DC motor controller board, an AC induction motor controller board and a DSP board.
Crossbow extends the concept in that it provides a development environment for the new Freescale parts – and other MCUs yet to be announced that will not be part of the Flexis range – in an interchangeable format. The MCU itself is mounted on a small “mezzanine” board that plugs onto the main pcb. Crossbow. You can, the company says, design a complete system using the 8-bit part, and simply plug in the corresponding 32-bit chip to evaluate the effect of the more powerful chip in your system. Future supplies a special free edition of CodeWarrior tools with the Crossbow board. Features include CAN 2.0B and USB 2.0 interfaces, LCD driver ports, I2C and SCI buses, 8-channel ADC, sockets for connectBlue Bluetooth module, Freescale ZigBee module and MaxStream ZigBee module.
As with other Future-Blox boards, Crossbow will be available free of charge to qualifying developers – which, the company says, means anyone who can demonstrate a likely reasonable usage of the parts they host. Future also issues full manufacturing descriptions of the boards: although the company intends them explicitly as development and prototyping changes, it says it has already seen users adopt the board designs with minimal modifications for short production runs.