An asynchronous processor is being developed by ARM and Philips, with the aim of reducing power in smartcards, consumer electronics and automotive applications.
The firms will base their design on version five of ARM's instruction set, as used in the ARM7 processor, with 16-bit Thumb and DSP extensions. The asynchronous ARM will be able to integrate into both asynchronous and synchronous Asics, said the companies.
Asynchronous CPUs have some advantages like reduced power consumption because each section of the circuit only operates when data arrives, with local handshaking being used for control.
And because there are no clocks, the switching activity of transistors will not be concurrent, so electromagnetic emissions are also reduced.
ARM claims that their asynchronous technology uses a third to a tenth of the power consumption of regular synchronous designs. But the disadvantage is that asynchronous designs are harder to imply.