Chapter 13: Porting MicroMonitor to the ColdFire MCF5272

Overview

In this chapter, Ill walk through the process of porting the MicroMonitor boot monitor to a Motorola ColdFire MCF5272C3 evaluation board. Ill assume you have some familiarity with the MicroMonitor command set and that you have access to the source code (all of which is on the CD). Ill limit my discussion of the ColdFire to those details that are necessary to the porting process. Consider this chapter a lesson on the monitor porting process rather than on the MCF5272C3 or the ColdFire architecture.

I chose the MCF5272C3 evaluation board because:

• The MCF5272C3 CPU has a good set of built-in peripherals. Its size and complexity are a good match for MicroMonitor;

• The MCF5272C3 core is very similar to the popular Motorola 68000 series of microprocessors;

• Motorolas support web sites provide a lot of information on the CPU and the evaluation board, including the source code for their boot monitor;

• Although it is not used in this port, the ColdFires BDM interface is top of the line;

• The facilities built into the monitor shipped with the board make it very easy to install MicroMonitor. In fact, I can install MicroMonitor without even needing to overwrite the default boot monitor.

Since I am working with an evaluation board, I can immediately make a few convenient assumptions that could not be made if this were brand new hardware. I can assume the hardware design has been tested , I can assume I have correct schematics, and I can assume the example code in Motorolas boot monitor truly does illustrate how to manipulate the hardware correctly.

Tip 

If your project includes building new hardware and you are writing the firmware, try really hard to get an evaluation board for the CPU and to get the hardware designers to follow the evaluation board design as a reference. If the new hardware follows the evaluation board as a reference, you can work on firmware on the evaluation board, and, when the real hardware becomes available, the transition to the real hardware will be easy.