Microcontroller

The integrated circuit from an Intel 8742, an 8-bit microcontroller that includes a CPU running at 12 MHz, 128 bytes of RAM, 2048 bytes of EPROM, and I/O in the same chip.

A microcontroller (abbreviated MCU or µC) is a high integrated functional computer system-on-a-chip. It contains an integrated processor core, memory (a small amount of RAM, program memory, or both), and programmable input/output peripherals. In contrast to a microprocessor which only contains a CPU (the kind used in a PC).

Other terms for a microcontroller are embedded system and embedded controller, because the microcontroller and its support circuits are often built into, or embedded in, the devices they control.

In addition to the usual arithmetic and logic elements of a general purpose microprocessor, the microcontroller integrates additional elements such as RAM for data storage, read-only memory for program storage, flash memory for permanent data storage, peripherals, and input/output interfaces.

Microcontrollers often operate at very low speed compared to microprocessors (at clock speeds of as little as 32 kHz), but this is adequate for typical applications. They consume relatively little power (milliwatts or even microwatts).

Microcontrollers are used in automatically controlled products and devices, such as automobile engine control systems, remote controls, machines, appliances, power tools, and toys, these are called embedded systems.

Related pages

• Arduino
• Atmel AVR