CURRENT FEATURE ARTICLES

Databahn
High-speed serial I/O for programmable logic
Going Serial with your Backplane
by Jock Tomlinson, Lattice Semiconductor
Design-in Kits Simplify Serial PCB
by Brad Griffin, Cadence Design Systems
Patently Unobvious
How the patent system works for and against technology
Embedded Dilemma
Platforms, soft-cores, RTOS, oh my!
Bringing the Processor into the FPGA
by Rob Irwin, Altium Limited
Language Barrier
How will the next generation of FPGAs be designed?
What's the Right Language for DSP System-Level Design?
by Tom Feist, VP of Marketing, AccelChip, Inc.
Board with FPGAs
Challenges getting your FPGA to work - on your board

Suppose you travel by car. In order to get around, you need certain expertise and equipment, such as a license, maps, experience, and a car. Now suppose you want to get places faster. You’ll need more skill, a faster car, better routes, and possibly a way to avoid running afoul of the law. As you push the speed envelope more, the demands and risks increase dramatically.

Moving data around through a parallel bus or backplane is much the same story. The faster you go, the more design skill and attention to detail is required. Creepy problems like clock synchronization and signal integrity start to grow into unmanageable monsters.

At some point you need to make a break. You need to travel by air. If you fly, the demands on your expertise diminish, while your speed increases dramatically. You book the flight and get yourself to the airport at the appointed time, and someone else handles the rest. Sure, enormous complexity is involved in hurling you along ten thousand meters above the earth at near the speed of sound, but you don’t have to worry about that. Someone else handled all that complexity before you entered the picture. Welcome to the world of high-speed serial I/O. If you buy the right ticket, your data can be blasting along between devices, cards, or racks faster than you can say SerDes, and your FPGA vendor will have already worried about all the complexity for you ahead of time. [more]

Legacy Parallel to Serial Backplane Design and Considerations

Parallel digital interconnect and backplanes have existed since the advent of modern electronic systems.

PCI has emerged as the most pervasive interconnect and backplane drive technology, which was first introduced in the early 1990s as a chip-to-chip interconnect standard based on 32 bits of data that operated at 33 MHz on these modern systems. PCI has evolved over the years from 32 bit/33Mhz to 64 bit/66MHz, to most recently, 64bit/133MHz, with plans to migrate up to 266 MHz and beyond in the future.

Many system design engineers viewed PCI, as a vehicle to address not only their chip-to-chip interconnect design requirements, but also to migrate PCI into the backplane for board-to-board interconnect as well. PCI was never designed nor intended to be used in backplane applications or even in mid-plane interconnect applications. Nevertheless, many design engineers successfully deployed systems that utilized PCI as not only the chip-to-chip interconnect, but also as the board-to-board (backplane) interconnect. [more]

Design-in Kits Address Challenges of Multi-Gigabit System Interconnect

After performance requirements for a system have been established, selecting the right devices to integrate into the system is an important and time-consuming part of the high-speed product design cycle. Careful attention to interconnect constructs is required when selecting devices capable of moving data around a system at gigabit data rates. Many IC companies spend significant effort providing written documentation that guides users on how to design interconnects that work with their devices. Systems companies must then spend considerable time reading and interpreting the documentation in order to evaluate performance of various devices before moving on to the board/system design.

For the PCB or systems designer, the size, cost and performance of each device is carefully considered in spite of stringent time-to-market pressure. . The design guidelines from IC companies are typically documented in a combination of terminology—some of the terms may be very familiar to the electrical engineer and some, less familiar to the PCB designer. On the other hand, some of the documentation will be more in line with typical terminology used by the PCB designer and less so by the electrical engineer. [more]