Here is a simple article about introduction of microcontrollers and microprocessors.

Microprocessor

Microprocessor is nothing but a data manipulator. It manipulates or modifies data according to the instructions given. The “Instructions given” is the program what we are writing and giving it to the computer. (The computer what we are using has a microprocessor to which we will give programs to execute like C programs which they execute to produce certain result. The result is what we see in the computer’s screen)

Simply, microprocessor (μP) is an executer unit of instructions. μP has a very small memory to store the results and operands. The data is in the form of numbers.

The instructions (i.e.) program is stored in a separate memory called ‘Program Memory’. The data that has to be manipulated or processed is stored in a separate memory called ‘Data Memory’.

Data Means

Now we will describe what Data means…

In the field of microprocessor, data is a number. In human language, we represent numbers as 1,2,3,4,5,6,7,8,9,0 and its combinations. In computer’s language,(i.e.) microprocessor’s language, it knows only 2 numbers  {0,1}. So symbolically we have to represent the number 1,2,3,4,… using {0,1}

To understand this You need to study number systems.

Number Systems

In human system, to express a count ‘ten’, we use two digits. Do you know why and the logic behind all number systems. It’s simple.

->0,1,2,3,4,5,6,7,8,9

From 0 to 9, we use single digits. After that there is no number or characters to express the count so we increase the no of digits -> 1_

After that we start counting from 0 to 9, --> 10,11,12,13,14,15,16,17,18,19

Again we increase the second digit by one and start counting from 0 to 9, ->20,21,22,23,24,25,26,27,28,29……………..98,99

After you reach 99, you again increase one digit and start counting from 0-9, ->100,101,102,…109,

->110,111,112………..

This is how the number system works.

Let’s try with octal number system

->0,1,2,3,4,5,6,7

After 7 there is no number exist in octal system. So increase the no of digits and start counting->1_

->10,11,12,13,14,15,16,17

Again increase the second digit and count

->20,21,22,23,24,25,26,27…….

Here the number 10 expresses the count ‘eight’

11 expresses the count ‘nine’

12 expresses the count ‘ten’

13 expresses the count ‘eleven’ and so on.

Similarly we try for hexadecimal system,

->0,1,2,3,4,5,6,7,8,9

After 9 still we have numbers or characters to express the count ‘ten’

->0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F

After ‘F’ (expresses the count 15), we increase the no of digits and start counting from 0 to ‘F’

->10,11,12,13,14,15,16,17,18,19,1A,1B,1C,1D,1E,1F

->20,21,22,23,24,25,26,27,28,29,2A,2B,2C,2D,2E,2F….

‘A’ represents the count ‘10’

‘B’ represents the count ‘11’

‘C’ represents the count ‘12’

‘D’ represents the count ‘13’

‘E’ represents the count ‘14’

‘F’ represents the count ‘15’

Totally from zero to 15, we express 16 numbers. That’s why it is called as ‘Hexadecimal System’

Binary System

0->0

1->1

2->10

3->11

4->100

5->101

6->110

7->111

8->1000

9->1001

10->1010

11->1011

12->1100

13->1101

14->1110

15->1111