The Theory

What we all have in our computers now are general purpose processors. These processors are designed to perform a variety of functions from doing mathematical computations to moving data from one memory location to another. Hence, they cannot be optimized to run a certain category of instructions such as DSP algorithms.

But with reconfigurable computing, you can! You will have one general purpose processor controlling anywhere from one to a large array of field programmable gate arrays (FPGA).

What's a FPGA?

For years, the industry has been using field programmable gate array boards to test digital designs. An FPGA contains thousands of transistors with programmable connections between them. How the transistors are connected is will depend on the design you load. Therefore, you can use a FPGA to build anything from a simple adder to a USB controller! This allows the designer to test his design out on a FPGA board before sending it to the fab.

Imagine if we use a FPGA in a PC.

The FPGA can configure itself to provide the most optimal architecture for the situation. It can continuously reconfigure itself as the situation changes. This boosts the speed of your software without the need to increase the clock speed!

For example, when you are playing Doom III (we can dream!), you enter a room with millions of polygons. This requires a high amount of 128-bit mathematical calculations. The FPGA can configure itself to do those multiplications in one clock cycle or at least faster than a general purpose processor can do.

Then you hear a sound coming from the back. This is going to involve DSP operations. Your FPGA then reconfigures itself into a DSP processor! This allows it to process DSP operations faster than a general purpose processor!

You may say that one can easily get dedicated graphics and sound processors to do the job. This is true. But it also means you will have to go out and spend hundreds of dollars to buy new graphics or sound cards when they come out if you want to play the latest games. With reconfigurable computing, all you need to do is just install software upgrades that tell your FPGA how to reconfigure itself into the latest graphics or sound processor!