First released in 2013, their function is to collect sensor data from integrated accelerometers, gyroscopes and compasses and offload the collecting and processing of sensor data from the main central processing unit (CPU).

It uses an ARM Cortex-M3 core with a customised packaging and naming scheme indicating that it is for an Apple customized part.

[17] The M-series motion coprocessors are accessible to applications through the Core Motion API introduced in iOS 7, so they do, for example, allow fitness apps that track physical activity and access data from the M processors without constantly engaging the main application processor.

They enable applications to be aware of what type of movement the user is experiencing, such as driving, walking, running, or sleeping.

[21] In iOS 10, the motion coprocessor is used to implement raise-to-wake functionality, reducing idle energy usage.