单片机是一种集成在电路芯片，是采用超大规模集成电路技术把具有数据处理能力的中央处理器CPU随机存储器RAM、只读存储器ROM、多种I/O口和中断系统、定时器/计时器等功能（可能还包括显示驱动电路、脉宽调制电路、模拟多路转换器、A/D转换器等电路）集成到一块硅片上构成的一个小而完善的计算机系统。

-SCM is integrated in a circuit chip, is the use of very large scale integrated circuit technology have data processing capability of the central processor CPU ram, Rom ROM RAM, multiple I/O port, and interrupt system timer/timer function ( may also include a display drive circuit, a pulse width modulation circuit, analog multiplexer, A A/D converter circuit ) is integrated into a piece of silicon constitutes a small but perfect computer system.