ARM has gone back to its beginnings developing a 12,000 gate CPU. Unlike the 1984-vintage 25,000 transistor 16-bit ARM1 which was designed to run a computer, the new 32-bit ARM Cortex-M0 is designed to power a microcontroller.
“It’s the smallest, lowest power processor ARM has ever made”, Dr Dominic Pajak, product manager at ARM’s processor division, told EW.
The core is tiny, occupying 0.25mm2 at 180nm. It dissipates 85µW per MHz, can run at over 100MHz on 180nm, but is usually limited by the flash to run at 50MHz at 180nm, and uses 60 instructions. By contrast: “The 8051 has about 100 instructions," said Pajak.
Pajak describes the MO as: “Deeply embedded, very deterministic, interrupt-driven, with a three stage pipeline.” It’s been designed to run on TSMC’s ultra-low-power process.
NXP was the lead adopter of the Cortex-M0. NXP has a family of ARM-based microcontrollers which it obtained from Sharp.
Last year revenues from microcontrollers were the fastest-growing sector of ARM’s business overall, growing 80%. “They’re used in electric motor control, in toys and games with on-board A/Ds and typical microprocessor peripherals," said ARM’s CEO Warren East.
As well as in microcontrollers, ARM sees the Cortex-M0 being used in configurable mixed signal devices bringing intelligence to sensors and accelerometers, and useful for ultra-low-power Bluetooth.
“It provides an upgrade path for the 8-bit and 16-bit people who are running out of headroom," said Pajak.
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