Today’s microprocessors sport a general-purpose design which has its own advantages and disadvantages.
- Adv: One chip can run a range of programs. That’s why you don’t need separate computers for different jobs, such as crunching spreadsheets or editing digital photos
- Disadv: For any one application, much of the chip’s circuitry isn’t needed, and the presence of those “wasted” circuits slows things down.
Suppose, instead, that the chip’s circuits could be tailored specifically for the problem at hand–say, computer-aided design–and then rewired, on the fly, when you loaded a tax-preparation program. One set of chips, little bigger than a credit card, could do almost anything, even changing into a wireless phone. The market for such versatile marvels would be huge, and would translate into lower costs for users.
So computer scientists are hatching a novel concept that could increase number-crunching power–and trim costs as well. Call it the chameleon chip.
Chameleon chips would be an extension of what can already be done with field-programmable gate arrays (FPGAS).
An FPGA is covered with a grid of wires. At each crossover, there’s a switch that can be semipermanently opened or closed by sending it a special signal. Usually the chip must first be inserted in a little box that sends the programming signals. But now, labs in Europe, Japan, and the U.S. are developing techniques to rewire FPGA-like chips anytime–and even software that can map out circuitry that’s optimized for specific problems.
The chips still won’t change colors. But they may well color the way we use computers in years to come. it is a fusion between custom integrated circuits and programmable logic.in the case when we are doing highly performance oriented tasks custom chips that do one or two things spectacularly rather than lot of things averagely is used. Now using field programmed chips we have chips that can be rewired in an instant. Thus the benefits of customization can be brought to the mass market.
A reconfigurable processor is a microprocessor with erasable hardware that can rewire itself dynamically. This allows the chip to adapt effectively to the programming tasks demanded by the particular software they are interfacing with at any given time. Ideally, the reconfigurable processor can transform itself from a video chip to a central processing unit (cpu) to a graphics chip, for example, all optimized to allow applications to run at the highest possible speed. The new chips can be called a “chip on demand.” In practical terms, this ability can translate to immense flexibility in terms of device functions. For example, a single device could serve as both a camera and a tape recorder (among numerous other possibilities): you would simply download the desired software and the processor would reconfigure itself to optimize performance for that function.
Reconfigurable processors, competing in the market with traditional hard-wired chips and several types of programmable microprocessors. Programmable chips have been in existence for over ten years. Digital signal processors (DSPs), for example, are high-performance programmable chips used in cell phones, automobiles, and various types of music players.
Another version, programmable logic chips are equipped with arrays of memory cells that can be programmed to perform hardware functions using software tools. These are more flexible than the specialized DSP chips but also slower and more expensive. Hard-wired chips are the oldest, cheapest, and fastest – but also the least flexible – of all the options.