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Microcontroller is the advanced version of microprocessors. It contain on chip Central Processing Unit (CPU), Read only memory (ROM), Random access memory (RAM), Input/Output unit, Interrupts Controller etc.

Therefore a microcontroller is used for high speed signal processing operation inside an embedded system. It acts as a major component used in designing of an embedded system.

Let's see the block diagram of microcontroller:

Embedded System Microcontroller

Let's see the basic components of microcontroller:

  • Arithmetic and Logic Unit (ALU): ALU inside a microcontroller used to perform the arithmetic and logic operation. It performs the logic operation on the data stored inside a register.
  • Accumulator: Accumulator is the register inside which the intermediate arithmetic and logical operation data is stored.
  • I/O ports: I/O ports are used for connecting input devices like sensor, keyboard etc with input ports and output devices like LCD, buzzer etc with output ports available in microcontroller.
  • Working registers: Registers are the storage device used to store the data inside a microcontroller in different address location.
  • Program counter: Program counter is used for counting the number of program executed inside a microcontroller.
  • Stack pointer: Stack pointer act as a pointer to the certain address. It is a register used to store the address of the last program request made by the processor inside a stack.
  • Clock circuit: Clock circuit is used for generate the clock pulse required as a reference signal for the microcontroller.
  • Interrupt circuit: Interrupt circuit is used for generating the interrupt signal when the higher priority process required to be served first on basis of priority by microcontroller.
  • Internal ROM: Internal ROM is read only memory used to store the information in embedded system. It acts as a main memory for storing the instruction and data inside a microcontroller.