http://improvec.blogspot.in/ 1

Interaction between CPU, memory & input/output device, functions of CPU

http://improvec.blogspot.in/ 2

Objective

On completion of this period, you would be able to learn:

Blocks of Computer System

Interaction between functional blocks

Functions of CPU

http://improvec.blogspot.in/ 3

Recap What is a computer?

It is an electronic device which processes the data Functional units of a computer

Input unitMemory unit ALU CUOutput unit

http://improvec.blogspot.in/ 4

Prerequisites

What are parts of the computer?

Input Unit

Memory Unit

CPU

Output Unit

What is CPU?

Central Processing Unit

http://improvec.blogspot.in/ 5

Interaction between functional blocks

MEMORY UNIT OUTPUT UNITINPUT UNIT

CONTROL UNIT ALU

data

instruction read writeresult

To user

(Result)

Control signals

operand

___ data flow

------Control flow

http://improvec.blogspot.in/ 6

Interaction between Functional Blocks

Data is supplied to the computer through an input device.

The data is then transferred to memory under the supervision of the control unit.

http://improvec.blogspot.in/ 7

Interaction between functional blocks (contd)

Each instruction is interpreted before execution

Control unit informs the ALU of the precise operation to be performed and

Directs the transfer of operands to the ALU

http://improvec.blogspot.in/ 8

Interaction between functional blocks (contd)

The ALU then performs all calculations and comparisons needed

And the results are then passed unto the memory unit, from there to the output unit

http://improvec.blogspot.in/ 9

CPU (Central processing unit)

http://improvec.blogspot.in/ 10

CPU

CPU is the heart and brain of a computer.

It receives data as input.

Follows instruction, and processes data

accordingly.

Presents the information as out put to the user.

http://improvec.blogspot.in/ 11

CPU (contd)

Its primary function is to execute programs.

it controls & coordinates all components such as memory, input and output devices.

http://improvec.blogspot.in/ 12

Blocks of CPU

Fig 1

http://improvec.blogspot.in/ 13

CPU (Central Processing Unit)

ALU (Arithmetic & Logical Unit) It performs two types of operations

1. Arithmetic Operations.

2. Logical Operations.

http://improvec.blogspot.in/ 14

ALU (Arithmetic & Logical Unit)

Operation : Symbol

Addition : +

Subtraction : -

Multiplication : *

Division : /

http://improvec.blogspot.in/ 15

Logical Operations

Logical AND Logical OR Logical NOT

Logical EXCLUSIVE OR

http://improvec.blogspot.in/ 16

CU (Control Unit)

Controls the operations that takes place in various parts of a computer by sending electronic signals.

Supervises the flow of data in various parts of computer such as input device, output device, and memory devices.

http://improvec.blogspot.in/ 17

CPU

http://improvec.blogspot.in/ 18

Functions of CPU

CPU performs everything in binary form

It takes the information and process it according to instructions.

It performs all calculations.

It takes all decisions.

It controls all units of computer.

http://improvec.blogspot.in/ 19

Summary

In this class, you have learnt about

Blocks of CPU

Functions of CPU

Interaction among the functional blocks

http://improvec.blogspot.in/ 20

Questions

1. Explain the interaction between CPU, memory and I/O devices?

2. Describe the functions of CPU?

http://improvec.blogspot.in/ 21

Quiz

1. The control unit, together with the ALU and memory unit, form a. control unit

b. memoryc. CPU (central processing unit)

d. ALUAnswer: c

http://improvec.blogspot.in/ 22

Quiz (Contd...)

2. The program’s instructions and data are transferred under the control of a. CPU

b. Control Unitb. ALU

d. Memory UnitAnswer: b

http://improvec.blogspot.in/ 23

Quiz (Contd...)

3. ALU handles a. arithmetic operations

b. logical operationsc. arithmetic operations and logical operations

d. None of the aboveAnswer: c

http://improvec.blogspot.in/ 24

Assignment

• Open a CPU cabinet with the help of your teacher (expert), and try to understand the connections and working of various components in side.