Boffins aim for clockless chip

A team of researchers at Manchester University is aiming to develop a new version of the ARM chip without a "clock".

The project is lead by Steve Furber, Professor of Computer Engineering at Manchester University, is to develop the Acorn RISC processor which became the basis of the ARM processors.

Furber's team is planning to spin out as a commercial operation, Self-Timed Solutions, with a product aimed at the growing smart card market, according to the Electronic Engineering Times.

Known as Amulet, the device belongs to a family of processors which has promised much, but thus far failed to deliver. The concept of a clockless processor has been around for a long time, but has not yet made it into large-scale commercial applications. Phillips, Sun and Intel have all experimented with them.

In normal processors, all the logical operations are carried out on a fixed regular schedule determined by a clock. So in a 500MHz processor, simple operations are carried out 500 million times every second.

In a clockless or "asynchronous" processor, different parts of the processor are allowed to run at their own schedule - So if they are not being used, they run on a slower clock and use less power.

This makes them an attractive option for processors designed to cope with "bursty" applications where power is scarce - Mobile video-phones are a typical example.

Asynchronous processors are also meant to have lower radio frequency emissions, another attractive feature for the wireless device market.