News Story by Jaikumar Vijayan

MARCH 22, 2004 (COMPUTERWORLD) - Though the concept of reconfigurable computing has been floating around for years and has attracted the attention of several researchers and vendors, there still is no commonly accepted definition of the term.

In its purest sense, reconfigurable computing involves chips or systems capable of modifying themselves on the fly, while running, to meet different application needs, says Jim Turley, an independent microprocessor analyst in Pacific Grove, Calif.

However, that definition is a lot narrower than the ones most people apply to the term, he says. ``Reconfigurable computing is a vague and squishy term that means a lot of different things to different people,`` Turley says.

``About half the companies I talk to don`t have chips that modify themselves on the fly, but they still consider themselves RC [reconfigurable computing] vendors,`` he says.

Most often, vendors and researchers are talking about field-programmable gate arrays (FPGA) and programmable logic devices when they are talking about reconfigurability, says Nick Tredennick, editor of the Gilder Technology Report in Great Barrington, Mass.

FPGAs are chips whose internal logic can be changed as needed. Such chips are reconfigurable to the extent that they can be modified via software in the field to accommodate bug fixes or upgrades, for instance, or to support new protocols.

But such modifications don`t take place at clock speed, when the system is running, which is what truly reconfigurable computing involves, Tredennick says. It`s only when the logic within an FPGA can be manipulated at runtime that it becomes a truly reconfigurable system, he says.

Making that jump will take some doing, says Stephen Smith. a senior manager at Xilinx Inc., a San Jose-based vendor of FPGA and programmable logic devices.

``[Dynamic] reconfiguration is the area that`s garnered the most press but has had the least commercial success,`` Smith says.

``It`s going to take a whole new attitude towards using the configurability in FPGAs,`` Smith adds. Also needed are new tools for analyzing what kind of applications can be ``decomposed`` into the small enough parts needed to do on-the-fly reconfiguration, he says.

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