PDQ Board Overview
Using the PDQ Board's HCS12/9S12 - An Introduction to Software and Hardware Interfacing

The user guide for the PDQ Board is intended for those learning embedded system design and programming based on the Freescale HCS12/9S12 microcontroller. The PDQ Board is an excellent platform to become adept at software and hardware interfacing the HCS12/9S12 processors. We hope that this guide will help you turn your ideas into products.

This page is intended as a short form guide to the available software and hardware interfacing topics.

Be sure to peruse the introductory chapters, about:

• Becoming familiar with the hardware and software
• Getting to know the hardware, jumper switches and connectors
• Powering the board
• Installing and connecting to it

Throughout the user's manual, supportive examples clearly illustrate all applications of the HCS12 core and peripheral functions. Each hardware interface is supported by pre-coded device drivers that you can use directly from the high-level C language. For example, you can learn how to:

• Read and write to the parallel digital I/O ports
• Interface to hardware and connect external devices to digital I/O pins
• Use PWM (pulse width modulated) digital I/O to create waveforms, frequencies, and duty cycles
• Capture and respond to external events with timer-controlled I/O
• Acquire data using the ATD (analog to digital converter)
• Manage serial communications and queued serial lines
• Use the SPI (serial peripheral interface)
• Use the IIC (I2C) serial interface bus to communicate with external hardware devices
• Use the battery backed real time clock and calendar

Throughout the user's guide, numerous C language examples will show you step-by-step how to program the HCS12 and its many peripheral functions.

You'll learn to use the Mosaic IDE Plus, a full featured development environment and compiler based on the GNU C open source compiler, and customized for the expanded memory model used by the PDQ Board.

The IDE also includes hundreds device drivers and reusable utility functions to speed your programming. A subject sorted listing of the C functions will give you an idea of the scope and breadth of the software already written for you.

In particular, be sure to peruse the chapters about:

• Using paged memory
• Storing and accessing data variables in paged RAM and Flash memory
• Writing your first C program
• Writing and compiling programs
• Using the Mosaic IDE Plus
• Timekeeping and using the multitasking real time kernel
• Writing interrupt service routines
• Failure and runtime error recovery