PREFACE

This book is a collaborative enterprise and is based on the RapidIO specifications, white papers, articles and other contributions from members of the RapidIO Trade Association. As writer/editor, I have tried to offer a good single reference source for the RapidIO technology, explaining not only the technology itself but also its various applications and the reasoning behind its development. I have also tried to structure the presentation of the material to more naturally show how the technology works. This book does not replace the RapidIO specifications themselves and if there are conflicts between what is written here and what the specifications say, the specifications are right. This book is a good introduction for someone who is going to use the RapidIO technology, or contemplate its use at either the chip or system level.

Special thanks must go the Dan Bouvier and Bryan Marietta from Motorola, now Freescale, who led the initial technical development along with Bob Frisch of Mercury Computer Systems. Dan provided the vision and leadership, Bryan provided engineering insight and the words of the specification and Bob provided experience and unique customer insights into what works and what doesn't work in the world of high-speed interconnects. While the work started with the three initial developers, the contributors and contributions to the technology have continued to grow over the years. As befits a true, open standard, contributions have come from dozens of individuals and hundreds of participants. Through them the scope and power of the technology has grown tremendously. Applications we hadn't envisioned have emerged to capture the attention of many of the leading vendors of processors, DSPs, FPGAs, systems, software and test equipment. They have also managed to keep the RapidIO Trade Association busily developing new standards long after most of us were ready to put our pencils down believing we were finished.

When we started this work, we were focused on solving problems unique to embedded systems connectivity. While many other technologies have come and gone (most purporting to be 'the standard' solution to all connectivity requirements), none has been able to offer the full value proposition for embedded systems that RapidIO offers. When you are focused on your customer's requirements you will be able to offer a better solution to their problem. That is what we have tried to accomplish with RapidIO and the embedded systems market. The challenge has been in seeing all of the various embedded systems vendors as a single market or as a group of closely related markets. Then working to develop a great solution for the problems of this market.

When you step back and look at these embedded systems you begin to realize that most all electronics systems perform three basic functions. They process data, they 'move data around' and while they are doing this processing and moving they also save the data in various places along the way. You process data with processors like CPUs, DSPs and Network Processors, you store data in RAM, ROM, FLASH and hard disks, and you move data around on buses and interconnects like PCI, Ethernet, Fibre Channel, and RapidIO. In the area of 'moving data around' standards can help tremendously in simplifying system design. RapidIO was developed to provide standard ways to move data around within embedded systems based on a switched interconnect rather than a bus. It has the capability of replacing lots of existing bus or switch based technologies such as PCI, VME, Utopia, Infiniband, Ethernet (for in-system use) or SPI4. As well as the many proprietary interconnects that systems vendors develop because there just isn't the right solution available on the market.

Thanks should also go to: Craig Lund for his insight and perseverance, Alan Gatherer for suggesting that someone should write a book on this technology and for putting me in touch with the good people at John Wiley and Sons, Bill Quackenbush for his technical contributions, Gary Robinson for leading us through the standards setting process, David Wickliff, Louis-Francois Pau, Steve MacArthur, and Peter Olanders for the customer's insight that they provided, Rick O'Connor, Tom Cox, Victor Menasce, David Somppi and the other good folks at Tundra for all of their many contributions to the effort. Thanks to Greg Shippen for taking the baton and running the next leg. And to Kalpesh, Nupur, Jason, Sarah, John, Andy, Travis, Jim, Kathy, Greg and Stephane for making sure that the journey was always fun.

Sam Fuller

Austin, Texas