Micro Controller Basics

What is a Micro Controller?

A microcontroller is a single chip microcomputer made through VLSI fabrication. A microcontroller also called an embedded controller because the microcontroller and its support circuits are often built into, or embedded in, the devices they control. A microcontroller is available in different word lengths like microprocessors.

Block Diagram 

 A microcontroller basically contains one or more following components:

Central processing unit (CPU)	Random Access Memory) (RAM)
Read Only Memory (ROM)	Input/output ports
Timers and Counters	Interrupt Controls
Analog to digital converters	Digital to Analog converters
Serial interfacing ports	Oscillatory circuits

 

Click For detail in Components of Micro-controller 

        

A microcontroller internally consists of all features required for a computing system and functions as a computer without adding any external digital parts in it. Most of the pins in the microcontroller chip can be made programmable by the user. A microcontroller has many bit handling instructions that can be easily understood by the programmer. A microcontroller is capable of handling Boolean functions. Higher speed and performance. On-chip ROM structure in a microcontroller provides better firmware security. Easy to design with low cost and small size.

Advantages:

• Microcontrollers act as a microcomputer without any digital parts.
• As the higher integration inside microcontroller reduces cost and size of the system.
• Usage of a microcontroller is simple, easy to troubleshoot and system maintaining.
• Most of the pins are programmable by the user for performing different functions.
• Easily interface additional RAM, ROM, I/O ports.
• Low time required for performing operations.

Disadvantages:

• a) Microcontrollers have got more complex architecture than that of microprocessors.
• b) Only perform a limited number of executions simultaneously.
• c) Mostly used in micro-equipments.
• d) Cannot interface high power devices directly.

 

Some basic applications of a microcontroller are given below.

a) Used in biomedical instruments.

b) Widely used in communication systems.

c) Used as a peripheral controller in PC.

d) Used in robotics.

e) Used in automobile fields.

How is it different form a Micro-processor and why use a Micro-controller instead of a Micro-processor?

Though microprocessors are powerful devices, they require external chips like RAM, ROM, Input / Output ports and other components in order to design a complete working system. This made it economically difficult to develop computerized consumer appliances on a large scale as the system cost is very high.

Difference Between Micro-processor and Micro-controller

Micro-processor	Micro-controller
It is only a general-purpose computer CPU	It is a microcomputer itself
Memory, I/O ports, timers, interrupts are not available inside the chip	All are integrated inside the micro-controller chip
This must have many additional digital components to perform its operation	Can function as a microcomputer without any additional components.
Systems become bulkier and expensive.	Make the system simple, economic and compact
Not capable for handling Boolean functions	Handling Boolean functions
Higher accessing time required	Low Accessing time
Very few pins are programmable	Most of the pins are programmable
Very few numbers of bit handling instructions	Many bit handling instructions
Widely Used in modern PC and laptops	widely in small control systems
Ex. INTEL 8086, INTEL Pentium series	INTEL8051, 89960, PIC16F877