The ARM Cortex-M is a group of 32-bit RISC ARM processor cores licensed by Arm Holdings. They are intended for microcontroller use, and have been shipped in tens of billions of devices. The cores consist of the Cortex-M0, Cortex-M0+, Cortex-M1, Cortex-M3, Cortex-M4, Cortex-M7, Cortex-M23, Cortex-M33, Cortex-M35P.