title: computer operation subject: computer studies edd 5161 f educational communication &...
TRANSCRIPT
Title: Computer Operation
Subject: Computer Studies
EDD 5161 F
Educational Communication & Technology
About the author …
Name of student:
Fok Yan Ming
Student ID:
98039900
Introduction
The target audience are form 4 students.
This slide show will be presented as a lecture.
Computer Operation
What can you find in a personal computer?
Input device Input device
Output device
How about this case?
What can you find
In my body?
Central Processing Unit (CPU)
Control Unit (CU) It coordinate machine activities.
Arithmetic and Logic Unit (ALU) It performs data manipulation.
Memory Unit (This name is seldom used)
It accesses the main memory cells.
There are some components in each unit.
Control Unit Program Counter
Instruction Register
Instruction Decoder
Arithmetic and Logic Unit Accumulator
Status Register
Logic Circuit
Memory Unit Memory Data Register
Memory Address Register
Address Decoder
In Control Unit (CU)Program counter (PC)
To hold the address of the next instruction. Instruction register (IR)
To hold the instruction currently executed. Instruction decoder
To decode the instruction.
Let’s see how the control unit works!
Box 1
Box 2
Box 3
The Treasure Boxes
Clean theboard
See theteacher
CollectThe forms
Now the teacher give you three treasure boxes. Each box contain a command from the teacher.
You cannot open the boxes or read the commands yourself. The monitor knows which box should be opened and the monitress reads the command inside the box.
Box 1
Box 2
Box 3
The Treasure Boxes
Clean theboard
See theteacher
CollectThe forms
Box 1
The monitor knows which box should be opened.
Box 1
Box 2
Box 3
The Treasure Boxes
Clean theboard
See theteacher
CollectThe forms
Box 1
The monitress reads the commands.
Box 2
At the same time, the monitorprepares to show you the nextbox should be opened.
Box 1
Box 2
Box 3
The Treasure Boxes
Clean theboard
See theteacher
CollectThe forms
But you don’t knowEnglish! Oh!
?
Box 1
Box 2
Box 3
The Treasure Boxes
Clean theboard
See theteacher
CollectThe forms叫你擦黑板呀!
哦,我明白啦!
Box 1
Box 2
Box 3
The Treasure Boxes
Clean theboard
See theteacher
CollectThe forms
The monitor plays the role ofProgram Counter.
The monitress plays the role ofInstruction register.
The translator plays the role ofInstruction decoder.
Interpretation
001
010
011
Main Memory
Inp A
Sto B
End
::::
001Program Counter
Inp AInstruction Register
Program Decoder
In Arithmetic & Logic Unit (ALU)
Accumulator (ACC) To hold the result or intermediate result of
the operation temporarily.Status register (SR)
To hold the status flag which show the status of the content in the accumulator.
Logic circuit To perform arithmetic and logic operation.
AccumulatorThe accumulator acts as the note pad. You can jot down the intermediate result (or final result) of your calculation.
For example, when evaluating
(7.9 + 1.7) (2.4 – 1.8)
You better jot the result
(7.9 + 1.7) and (2.4 – 1.8)
on the note pad, right?
Status Register
It describes the current status of the accumulator.
When 0 or 1 is assigned to the flags in status register, the status can be shown.
For example,
9Accumulator
Status Register
odd integer positive zero
-2
Interpretation
In this example, we only have four flags.
You may imagine that if we have many flags….
we can describe the content in the accumulator accurately
Memory Data register (MDR) To hold the data or instruction to be stored
in or fetched from main memory.Memory Address register (MAR)
To hold the address of the memory location to be accessed.
Address Decoder To location the memory cell whose address
is stored in MAR.
In Memory Unit
In the previous example about control unit, the instruction seems to be accessed directly.Actually, we must access the main memory via the MAR and MDR.
Now lets see an demonstration.
001
010
011
Main Memory
Inp A
Sto B
End
:::
001
Program Counter
Inp A
Instruction Register
MAR
MDR
Address Decoder
001
Inp AInp A
Instruction decoder
IR PC
CU
Logic circuit
SR
ACC
ALU
Address decoder
MAR
Memory Unit
MDR
The Central Processing Unit
Summary
This is the end.
Click the button to exit.