The Great Gigabit Backplane Shootout Arrives!
10 Companies Answer A Baker's Dozen Questions To Shed Light
On The Science, Technology, Economics, And Politics Of High-Speed Backplane
Silicon.
by Lee Goldberg
January, 2003....It's been nearly six months since the i/oZONE section of analogZONE first proposed the idea of providing a forum in which manufacturers of multi-gigabit backplane transceiver silicon could debate the complex, and sometimes murky issues that factor into their technologies. And although it's taken about three months longer than I'd hoped to develop the questions and compile the answers, I think you'll find it was worth the wait.
The shoot-out came into being because of the conflicting claims being made between advocates of binary-level and multi-level signaling technologies (BLS/MLS.) Each claimed that their technology offered the highest-performance, lowest-cost, most energy-efficient way to ship multi-gigabit data streams across the noisy, hostile backplane environment.
As the debate evolved, we also began to look at issues within the more heavily-populated BLS community as well, and included questions about the optimum techniques for equalization, pre-emphasis, and other signal-correction techniques. The shootout also sought to glean industry experts' understanding of the other factors in backplane design, and how they drove the requirements of the silicon.
We've gotten responses from ten manufacturers of the original dozen we invited to participate, each answering a list of questions compiled after consulting with industry experts. Although there seem to be many areas of agreement in their answers, there also are many areas where manufacturers differ. As you will see, the divisions are most often along the BLS-MLS fault line, but there are several clear areas of disagreement within the BLS camp over the best equalization schemes, and the market's future directions.
As a bonus, we're proud to offer you several contributed white papers from the likes of PMC-Sierra and National Semi that should add to your insights on both backplane design, and the issues surrounding the semiconductors that go into them.
Of course, no study of this nature is ever definitive or complete. Despite our best efforts, there are probably many important questions that were not put to our participants, and several backplane silicon vendors who were somehow overlooked. If interest warrants, we'll be running a second part to the shootout, with additional questions that get raised as a result of this first forum. We are also open to the idea of opening the process up to any additional newcomers.
For now, however, there should be sufficient material here to inform, communicate, and stimulate a series of lively debates in this rapidly evolving field. If you have any questions, comments, or suggestions on this, or any other issue, feel free to write me at: lgoldberg@green-electronics.com.