Apple M7

[Eug]

Any speculation what M7 is?

At first I thought it might be a LITTLE in an ARM big.LITTLE configuration, but it doesn't really seem like it, at least from the press blurbs. They specifically label it as a "motion coprocessor". Before this week, I wouldn't have thought such a subset of usage would warrant a separate processor, but what do I know.

Perhaps this stuff is so low power that even a "little" CPU would be too much for it if it's operating 24/7? Apple chose to split off the lowest power always-on activities from the low power activities that other manufacturers might hand off to a "little" CPU?

 

[Phynaz]

A MEMS style gyroscope?

 

[Eug]

A MEMS style gyroscope?

They call it a coprocessor. I suspect the gyroscope would be separate (along with the accelerometer).

 

[Mopetar]

My guess is that it's an ARM SoC that has a very low clock, uses very little power, and exists only to interact with the accelerometer, etc.

They alluded that it was for saving power for when the device isn't doing anything else other than monitoring data. My guess is that they're still working on their watch and needed to design a really low-power component to handle some of the functionality expected out of a smart watch while minimizing the battery drain.

 

[liahos1]

let me tell you guys what it is. its a sensor hub similar to the one found in the s4 (atml makes that)

typically in apple mobile products all the sensor fusion (conversion of mems data output into something consequential for the device) is done in the apps processor. In this round apple has decided given the 9-axis mems to go to a sensor hub configuration). This allows the sensor fusion to be offloaded to another processor without burdening the cpu. This is not a big.little implementation (those are built onto SOC not separate die). there is no general purpose coprocessing here. this is a specific microcontroller built to do a specific task.

 

[sciwizam]

From the Moto X review, which also has a low power "core" for context.

http://www.anandtech.com/show/7235/moto-x-review/4

This stowage and contextual awareness detection comes through fusion of the accelerometer, gyro, and ambient light sensor data on a TI MSP430 controller which enables most of the active display features from what I can tell. These then are exposed as flat down, flat up, stowed, docked, and the camera activation (flick) gesture. The MSP430 also surfaces its own temperature sensor to the rest of Android, which is nifty (the Moto X has an accelerometer, gyro, pressure sensor, compass, and the MSP430’s temp sensor).

 

[Rakehellion]

Before this week, I wouldn't have thought such a subset of usage would warrant a separate processor, but what do I know.

Motion data, especially GPS, sucks up a ton of processing power. Having a dedicated processor for all of this makes it so you don't have to gimp your motion features to save battery life.