The design and specification of a computer architecture is an involved process, one that is becoming more challenging as microprocessors incorporate ever more sophisticated organizational structures. The author reviews this design process by surveying several microprocessor architectures developed by Motorola and discussing the important architectural aspects as they relate to system design. As the author notes in the preface, modern system design requires not only an understanding of the entire system but also a keen awareness of the effects of each design tradeoff. In approaching the material from this perspective, the text is quite different from most academic computer architecture texts. In this work, the focus is on understanding the problems and learning the right questions, rather than on obtaining in-depth technical knowledge of the underlying principles.

By focusing almost exclusively on Motorola products, the author works within a common architectural philosophy that allows an easy and logical flow when comparing system design issues. Since the text is not intended as a general survey of modern microprocessors, the focus on Motorola does not limit the effectiveness of the text. Moreover, key architectural issues, such as instruction set design, instruction set execution, and data paths, are sufficiently generic to allow the basic concepts covered in the text to be applied to other vendors’ microprocessors.

Although most of the material covered in the text examines reasonably complex topics, the author approaches the material with a light, conversational style. Overall, the focus is on helping the reader to understand how the microprocessor performs a specific function and--equally important--how aspects of the microprocessor’s architecture address key design problems. For example, the chapter that focuses on digital signal processors (DSPs) not only discusses the important architectural design elements, but includes an overview of a design problem particularly suited to the capabilities of a DSP.

The weakness of this big-picture approach is that it is not entirely clear who the audience for the text is. The text is not an academic work, in tone, approach, or technical content. If one considers it an introduction to the field, the lack of bibliographic references or suggestions for further reading leaves one without any guidance on how to learn more about this topic. Conversely, the technical designer faced with selecting a new architecture would find that, while the text clearly and thoroughly describes many design problems, it does not provide sufficient information to answer the questions it raises. Perhaps readers who would benefit most from this text are those with sufficient technical skills to conduct an independent technical analysis, but who are not aware of the architectural options currently available.

With respect to the organization of the text itself, the first section (chapters 1 to 5) describes the evolutionary development of the microprocessor and the three main architectural models (CISC, RISC, and DSP), along with a comparative review of CISC and RISC design models. In the second section (chapters 6 to 8), the focus changes from within the processor to the external design considerations, such as memory systems and interrupts, that can significantly affect the design and performance of a system. Although only 30 pages long, the applications-oriented material in chapter 9 demonstrates how many of the concepts presented in the text can be used to solve real problems. Most of the remaining chapters in the text (chapters 10 to 12) offer a look forward to the technical developments, both in terms of hardware and software, that a design engineer might see. The final chapter presents a broad-brush summary of the many design problems that should be considered, but offers few specific recommendations on how to solve them. The text concludes with two appendices on benchmarks (their use and misuse) and a brief overview of alternative architectures (such as the Intel 80x86 family).