A microcontroller ( abbreviated MCU or Â C ) 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 . A microcontroller ( sometimes abbreviated Â C , uC or MCU ) is a small computer on a single integrated circuit containing a processor core , memory , and programmable input\/output peripherals .