Page 10 - Digital Age - 3

2. CU (Control Unit)
Central Processing Unit
The Control Unit is the ‘Heart’ of the

CPU. It controls the flow of data and Control Unit
instructions between the ALU and Input Output
the Memory unit. It also controls the Device Arithmetic Logical Unit Device

overall functioning of the various
parts of the computer.
Memory Unit
3. MU (Memory Unit)

The Memory Unit stores data and instructions for a short duration of time before

and after the processing respectively.

Let us understand the IPO cycle and how the CPU works with an example. We want
to subtract 20 from 50 and display the result.

1. We type 50 - 20 using the keyboard. This is input.

2. The input comes to the Control Unit (CU).

3. The CU stores the numbers 50, 20 and the - operator in the Memory unit.
4. The CU sends the data to the ALU, which performs the subtraction and produces

the result 30. This is process.
5. The CU stores the result in the Memory unit.

6. The CU takes the result from the Memory unit and displays it on the monitor.

This is output.

Control Unit 50, 20, - Control Unit 50 - 20 = 30
Memory Unit ALU

30 Control Unit 30 Control Unit
Memory Unit

Try This Logical Thinking

Unscramble the letters to form words related to working of a computer.

1. CORSSPE ____________________
2. RYMOME TINU ____________________
3. ABODRTHMORE ____________________

4. UOPUTT ____________________

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