It seems like a contradiction in terms to talk about a resource-rich MCU in conjunction with the small, battery-powered application space that is wearables. But ARM aims to resolve that contradiction with its recent release of the Cortex-A32 processor. The combination of processor architecture and process technology in the new device does just that, boasting a 25% more efficient 32-bit core in as little as 0.25 mm2 of silicon.
The Cortex-A32 is built on ARM's ARMv8-A architecture and represents an upgrade path for the popular A-5 and A7 architectures used in many 32-bit application processors. Not only does it offer higher performance for lower power than the A7, the new A32 increases the resources available for handling 32-bit applications. More than 100 32-bit instructions have been added to the A32's architecture, including enhancements for media performance, software encryption, and floating point calculations.
The A32 is designed for scalability to address a range of applications. At the high end, a quad-core device can operate at GHz clock speeds, consuming less than 75 mW per core. In its smallest configuration, a 100 MHz single-core A32 with AMBA interface and 8k each of instruction and data cache takes less than 4 mW of power.
The A32 can offer the kind of performance needed in industrial applications such as gateways, robotics, and edge devices with local data analytics and control responsibilities. But the combination of rich resources and low power also make the A32 suitable for challenging wearable IoT applications. Smart watches, health monitors, and the like must be very power efficient in order to minimize user frustration around frequent battery charging or replacement. They also require sophisticated graphical interfaces, robust operating systems, and significant sensor processing capabilities in order to provide the functionality and rich user interface users demand. The A32 was designed to meet these seemly mutually exclusive requirements.