The ACPRD Project Page

Alarm Control Panel Reference Design using the Freescale MC9S12DP256

ACPRD reference design hardware


First of all, the Alarm Control Panel Reference Design (ACPRD) is not meant to be a sophisticated, high-end alarm device demonstrating the latest technology in the field of object surveillance or fire protection.

The main purpose of the ACPRD is to show, how the MC9S12DP256 MCU (microcontroller unit) can be used for a real-world industrial application, namely an Alarm Control Panel. The project is intended to help software developers and hardware designers understanding the MC9S12DP256 by demonstrating a large number of features of this new MCU.

The Reference Design delivers a comprehensive set of hardware building blocks as well as software library functions for the HCS12. The software is provided in a modular form, including ANSI-C source code, to allow easy re-use in other applications.

By Dec/9/2002, the ACPRD has become an official Freescale Reference Design.

What is an MC9S12DP256?

The MC9S12DP256 is a 16-bit microcontroller unit (MCU). The device belongs to the HCS12 family, Freescale's latest 16-bit microcontroller family. It has an impressive feature list, e.g.:

  • 16-bit HCS12 CPU with 25MHz max. bus speed
  • 256KB Flash, 4KB EEPROM, 12KB RAM
  • 16 channel 10 bit A/D
  • 2 x SCI/3 x SPI/1 x IIC/5 x CAN

Please note: the documentation of the MC9S12DP256 MCU is provided in a modular form, i.e. there are several data sheets for the CPU as well as for all peripheral blocks of this microcontroller. Please visit the Freescale MCU Homepage to get the latest data sheets.

Is there a detailed description of the ACPRD components?

A detailed description of the ACPRD hardware and software is contained in the ACPRD Designer Reference Manual, which is an official Freescale document.

This project page contains a general description of the project, as well as updates and additions that were made after the initial release version of the ACPRD.

Where can I get the latest version of the ACPRD Designer Reference Manual and related Software?

The ACPRD Designer Reference Manual is an official Freescale Document. It can be ordered by product order number DRM008/D. Check out Freescale's Alarm Control Panel Reference Design Page for PDF Download instructions!

A local copy of this document can be downloaded here: DRM008/D

To get the source code, you may access this local copy: ACPRD V1.00 C Source

Where to buy hardware components for the ACPRD?

The ACPRD Designer Reference Manual (see above) contains all the information that is necessary to create your own Alarm Control Panel Design from scratch.

However, if you want to minimize your design effort, you can purchase a prefabricated S12compact Controller Module, which is the heart of the ACP Reference Design.

S12compact Controller Module
S12compact Controller Module

S12compact controller modules are offered by Elektronikladen | ELMICRO (see list of sales offices in Europe, USA, Australia, Korea). Pricing starts in the USD150 range.

Currently, it is not planned to offer complete ACP devices (including base board, LCD, mechanical stuff etc.). Please contact the author (see below) if you are interested in getting the PCB files of the base board.

Where can I get an ANSI-C Compiler for the HC12/HCS12?

Some of the companies offering ANSI-C Compilers for the HC(S)12 are listed here (in alphabetical order):

Project News

Freescale and the University of Cooperative Education Lörrach have published another Reference Design, based on the ACPRD hardware. The title of this Reference Design is Internet Connectivity with HCS12 16-bit Microcontroller using the ACP Reference Design, a description can be found on Freescale's RDHCS12WSACP : Web Server and Email Client for Alarm Control Panel Reference Design page.

A local copy of the related Designer Reference Manual can be downloaded here: DRM049/D

About the Authors, Credits

  • The ACPRD was implemented by Oliver Thamm, Leipzig, Germany
  • PCB layout of the S12compact Controller Module made by Thomas Wurlitzer

Special thanks to:

  • J. Messingschlager (FRG Frischer Electronic/NDK) for his invaluable advise on quartz crystal technology and oscillator design
  • Marianne Göttler (vaREP3000/Alliance) for the support regarding high-speed RAM devices
  • Dr. Gerald Kupris from Freescale and a lot of other friendly poeple there who helped giving birth to the ACPRD :-)

Please send suggestions and inquiries concerning this page to
The original URL of this page is
Back to Oliver Thamm's HC12 Web