Microcontroller .. Know it more

     A microcontroller is a single chip, self-contained computer which incorporates

     all the basic components of a personal computer on a much smaller scale

     A microcontroller is a programmable single chip which controls a process or 

     system

Microcontrollers are designed to be low cost solutions

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Microprocessor vs. Microcontroller

Microprocessor requires several other components for its operation such as program memory and data memory, input-output devices, and an external clock circuit

 Microcontroller, on the other hand, has all the support chips incorporated inside its single chip

    Microprocessor = CPU only 

Microcontroller = CPU + Memory + Clock Circuit + Peripherals

    

A microcontroller differs from a microprocessor in many ways. The first and most important difference is its functionality.

In order the microprocessor may be used, other components such as memory or components for data transfer must be added to it. Even though

the microprocessor is considered to be a powerful computer machine, the weak point is that it is not adjusted to communication to peripheral environment.

Simply, in order to communicate with peripheral environment, the microprocessor must use specialized circuits added as external chips. It means in short that microprocessors are the pure heart of the computers. That is how it was when they appeared and the same is now


Basically, a microcontroller is a device which integrates a number of the components of a microprocessor system onto a single microchip. 

So a microcontroller combines onto the same microchip : 

The CPU core (microprocessor)

Memory (both ROM and RAM)

Some parallel digital I/O

Also, a microcontroller is part of an embedded system, which is essentially the whole circuit board. 

The difference is that microcontroller incorporates features of microprocessor(CPU,ALU,Registers)along with the presence of added features like presence of RAM,ROM,I\O ports,counter etc.Here microcontroller control the operation of machine using fixed programme stored in Rom that doesn't change with lifetime

A Microcontroller is basically a computer on a chip. It differs form normal desktop or laptop computers in that a microcontroller is an application specific computer that usually runs a single program performing dedicated task(s) while the the later two are general purpose computers that can run numerous programs depending on a users needs. A microcontroller contains on chip CPU, input/output interface, memory, clock, timer, and an assortment of of other peripherals.


A Microprocessor on the other hand is just a CPU one has to add externally memory, clock, input/output interfaces, timer and all other needed peripheral. This is the reason a microprocessor has so many pins.