A microcontroller (sometimes abbreviated µC, uC or MCU) is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals, program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM. Microcontrollers are designed for embedded applications. MCUs are commonly available in 8-bit, 16-bit and 32-bit. Avnet Memec suppliers’ Renesas Electronics, Energy Micro and Silicon Labs offer MCU with additional peripherals including Touch Sense or Power Line Communication (PLC) and can be targeted at Low Power Applications. Other peripherals can include Wireless Communications Protocols such as Zigbee or Near-Field Communication (NFC) – these types of MCU are now referred to as Wireless MCU.

MCUs can different core processing engines. Energy Micro, an Avnet Memec MCU Supplier specialising in energy friendly ultra low power applications, is an ARM-Based Processor using ARM Cortex-M3 and Cortex-M0; Silicon Labs favour one of the longest lasting core in the industry, the 8-bit 8051. By contrast, Renesas Electronics, the largest MCU supplier in the world, offer a various families of proprietary core, from the 8-bit RL78, up to the 32-bit V850 and RX.