ARM Cortex-M7: a more powerful microcontroller for connected more autonomous objects

The ARM company yesterday announced its new microcontroller generation Cortex-M7, which brings doubled performance and opens the way for more self connected objects.

Unlike Cortex A-series, upon which a majority of phones and tablets, Cortex M series are not microprocessors, microcontrollers are. Lacking memory controller, they are unable to perform general operating systems such as Windows or Linux (ie Android), but they are nevertheless increasingly important.

Microcontrollers actually animate, among others, all kinds of connected objects. Since the birth of the range in 2004, 8 billion processors including at least one heart Cortex-M were delivered, of which 2.9 billion in 2013 and $ 1.7 billion in just the first quarter of 2014.

ARM Cortex-M7

Architecture and improved computing power

To meet this burgeoning market, ARM has launched the Cortex-M7, which brings improvements in terms of architecture computing power.

The new architecture provides such calculation in double precision floating point (single precision on M4), caches of instructions and data, dedicated improvements in digital signal processing, and an interface Tightly Coupled Memory (TCM) a kind of cache extent (up to 16 MB) and programmable (as opposed to non-programmable traditional caches 64 kB).

In terms of computing power, the M7 would be twice as efficient as the most efficient microcontrollers to date, its predecessor, the M4. One passes for example from 1.25 to 2.14 DMIPS / MHz Dhrystone test, and 3.4 to 5 CoreMark / MHz. Also the maximum frequency of 168 passes at 400 MHz.

Double the performance to extend autonomy, contradictory?

Thus the Cortex-M7 can firstly replace multiple dedicated DSP, who can treat one type of signal (audio, video, movement, etc.). The company may also reduce the need for an application Cortex-A, by appropriating certain operations.

It thus opens the way for connected objects hybrids, where the Cortex-M microcontroller is the main chip, constantly alert, and the application Cortex-A coprocessor, woke up only when the user interface is requested. Until now it was rather the opposite, which in particular explains the reduced autonomy of connected watches, according to ARM, who believes that we could reduce consumption by up to 85% by optimizing the design of the devices.

Extending the life of objects connected while doubling performance might seem contradictory, but it is by appropriating the functions formerly assigned to greedy applications processors derivatives phone market as the Cortex-M7 succeeds.

ARM Cortex M7 diagram
The architecture ARM Cortex-M7 is already available to manufacturers, who will be able to realize from one day to another. Manufacturers such as Freescale and STMicroelectronics have already acquired licenses. So we should not soon see new products to enjoy on markets wearables (Watches, glasses), connected objects but also automotive and industry.Edited on 09/25/2014 at 1:32 p.m.