2. Starter Activity: What is it?
You will be given a small part of a computer. In
groups of 4 you are to discuss what you think it is
and how it might work. Be ready to feedback your
thoughts to the rest of the class.
Fetch Execute Cycle
3. In this lesson you will learn about what a CPU is,
what it does and how it works. You will create an
annotated diagram of a CPU that explains the
different operations of the fetch execute cycle.
Lesson
Objectives
Understand the purpose of a CPU and its role
Be able to describe the components of a CPU
Be able to locate a CPU in a computer
Be able to explain the fetch execute cycle
Fetch Execute Cycle
4. What is a CPU
Watch the What is a CPU video, this will introduce
you to what a CPU is.
Fetch Execute Cycle
5. CPU (Central Processing Unit)
•The CPU (Central Processing Unit) is commonly
referred to as the “brains of a computer”
•The CPU is also know as a processor
•It is responsible for executing a sequence of
instructions called a program
•The program will take inputs, process them and
output the results
•CPUs are in mobile phones, washing machines,
tablet computers
Fetch Execute Cycle
6. Task 13: CPU Drawing
Using a paint program create a drawing of a CPU. It
must be a realistic. (10cm x 10cm)
Fetch Execute Cycle
7. Where is the CPU?
The CPU sits in the motherboard of the central unit.
Fetch Execute Cycle
8. Components of a CPU
•Control unit- Coordinates and controls all parts of
the computer system
•Arithmetic Logic unit- Performs arithmetic or
logical operations
•Register- Stores the most frequently used
instructions and data
Fetch Execute Cycle
9. The Control Unit
Control Unit- Manages four basic operations (Fetch
Execute Cycle)
•Fetch- Gets next program instruction from the
computer’s memory
•Decode- Figure out what the program is telling the
computer to do
•Execute- Perform the requested action
•Store the results to a register or to memory
Fetch Execute Cycle
10. The Arithmetic-Logic Unit (ALU)
Arithmetic-Logic Unit (ALU)- Perform basic
arithmetic or logic operations
•Add, Subtract, Multiply, Divide
•Compare two items to see which one is larger or
smaller
Fetch Execute Cycle
11. How a CPU works – Fetch Execute Cycle
Fetch Execute Cycle
Control unit ALU
Memory
12. Task 14: Parts of a CPU
Create a word document and add a SmartArt text
cycle with four text boxes. Add the four basic
operations of the Fetch Execute Cycle in the text
boxes. Fetch, Decode, Execute and Store.
Copy and paste your drawing of the CPU into the
middle of the circle.
Fetch Execute Cycle
13. Drinks Machine – Fetch Execute Cycle
Lets think of the Fetch Execute Cycle like a drinks
machine. Customer presses the coke button.
The stuff could be a number, a word or an
instruction. The next customers arrives and
presses the lemonade button – this is the cycle.
Fetch Execute Cycle
Address Stuff
1 Load 41
2 Load 42
3 Load 67
41 Coke
42 Lemonade
Fetch
Load 41
Execute
Memory
14. Task 15: CPU Annotation
Annotate your diagram to explain exactly how a
CPU works. You must explain the four operations
of the fetch execute cycle .
Fetch Execute Cycle
15. Plenary: Calculator
Using only words explain how a CPU would add
up three numbers. (The computers calculator)
Fetch Execute Cycle
16. Keywords
Understand the purpose of a CPU and its role
Be able to describe the components of a CPU
Be able to locate a CPU in a computer
Be able to explain the fetch execute cycle
Objectives
CPC
Motherboard
Control Unit
Arithmetic Logic Unit
Fetch
Decode
Execute
Store
Fetch Execute Cycle
