Designing with Microcomputers -- The 68HCS12 and 68HC12

Overview and History


Sixth Revision (2015) now shipping!

I've developed CD based textbook and simulator packages for the 68HCS12 and 68HC12 which are available via this site.

In 1999, after teaching a microncontroller course using the Motorola 68HC11, I felt that students would be better served by a more modern microcontroller, so I switched to the 68HC12 and more recently the 68HCS12. However there was a problem: no textbook was available, and while there was a free assembler, there was no reasonably priced simulator. It's much easier to learn beginning programming with a simulator than with a debugger on the target hardware!

So over the years I wrote both a textbook, HTML based, and a simulator. I distribute them on CD to my students each term. The original simulator for the 68HC12 I've always distributed for free from my website, and I will continue to do so. But in 2004 I decided to make the CD textbooks and the 68HCS12 simulator available to students and individuals who want to learn these microcontrollers on their own.

The textbooks are hyperlinked for cross references and to the Freescale documentation, and will also launch the simulator for example programs in the text. In addition the textbooks are fully indexed. The 68HCS12 text can be printed, in whole or part, for personal use, using the supplied PDF format file. Printed, softbound copies of this text are also available.

Please note that running the simulator from within the text using a browser is becoming less possible and will not be possible with any browser in the near future. The issue is that the simulator in this case must run as a Java Applet, a technology that is being abandoned. However this does not prevent running the example programs from outside the browser using the simulator "stand alone".

CD Based Instruction Advantages

Many people are nervous about having a CD based text; however, there are many advantages:

The simulators are written in Java and have been tested under Microsoft Windows 2000 through 10, Red Hat and Ubuntu Linux, and Mac OS X 10.4 through 10.11. The textbook being in HTML and PDF is readable under any of these systems. The included assembler is compiled for Windows but source code is provided which can be compiled for other environments. The included assembler IDE is for Windows only.