ARM Offers First Clockless Processor Core

Sam Haine '95 writes "EETimes is reporting that ARM Holdings have developed an asynchronous processor based on the ARM9 core. The ARM996HS is thought to be the world's first commercial clockless processor. ARM announced they were developing the processor back in October 2004, along with an unnamed lead customer, which it appears could be Philips. The processor is especially suitable for automotive, medical and deeply embedded control applications. Although reduced power consumption, due to the lack of clock circuitry, is one benefit the clockless design also produces a low electromagnetic signature because of the diffuse nature of digital transitions within the chip. Because clockless processors consume zero dynamic power when there is no activity, they can significantly extend battery life compared with clocked equivalents."

Comments

Sun was talking about clockless chips in 2001

[tjstork]

Sun exhorts people to make clockless chips

Re:Overdoing it

[langelgjm]

I know nothing about microprocessor design, but a simple answer would be to have a temperature sensor attached to a voltage regulator. When the temperature gets too high, reduce the voltage, and consequently, the speed (that is, assuming the other few posts I skimmed were correct - always a toss-up on /.).

You'd have to specify a specific benchmark...

[mbessey]

There's no easy answer. On a traditional clocked processor, each instruction takes a certain number of clock cycles. In the async case, everything just takes however long it takes. In fact, some arithmetic operations might take variable amounts of time depending on the value of the operands.

Given an equivalent process, layout technology, and number of transistors, an async design will be at least somewhat faster and vastly more power-efficient than a clocked design.

But none of those things are going to be equivalent in the real world - except possibly the process that ARM designs to. So comparisons will be difficult.