Section 5 - Computer organisation and architecture

Question 1

Each processor has its own instruction set, list all the instructions that are typically supported by its hardware.

Answer 1

• Data Transfer
• Arithmetic operations
• Comparison operations
• Logical operations
• Branching (conditional and unconditional)
• Logical processing (shifting bits)
• Halt

Question 2

2 types of basic data transfer instructions?

Answer 2

Load & Store

Question 3

Examples of arithmetic operational instructions?

Answer 3

Add & Subtract

Question 4

Examples of comparison operations typically supported by the processors hardware?

Answer 4

< (Less than) & >(Greater than)

Question 5

Examples of logical operations the processors instruction set can support?

Answer 5

And, Not, etc…

Question 6

What is the typical format of machine code operation?

Answer 6

Operation code(opcode) , which includes the machine instruction followed by the address mode.
Operand

Question 7

The size of the OPCODE and OPERAND can vary, explain why?

Answer 7

architecture –
word size –
processor type –

Question 8

Where are all operations assumed to take place?

Answer 8

a special register called the accumulator

Question 9

What can complex architectures allow for?

Answer 9

bigger OPCODE and sometimes 2 OPERAND’s

Question 10

How many digits is the code that represents the address mode in machine code?

Answer 10

2

Question 11

There are 3 types of address mode, explain.

Answer 11

Immediate, actual value operated on.
Direct, OPERAND holds the address of value to be operated on.
Indirect, holds the address of the memory that holds the address of the value to be operated on.

Question 12

What effects the performance of the processor?

Answer 12

CPU registers, CACHE, Main memory RAM, Secondary storage device type, Input sources

Question 13

What is the definition of a CPU’s word length?

Answer 13

the number of bits that the CPU can process simultaneously

Question 14

How is word length grouped in the CPU?

Answer 14

ie 8,16,32,64 or 128 bit ‘words’

Question 15

How is each ‘word’ processed in the CPU?

Answer 15

as a unit

Question 16

What effect does increasing word length have on the speed of processing?

Answer 16

A major impact.

16 bit processes twice the amount compared to 8

Question 17

What is the typical word length of a CPU and processing?

Answer 17

32 or 64 bits

Question 18

Explain why the width of the data and address buses has an effect on the processor?

Answer 18

An important factor
ie if bus width is 16 bits and address is longer than 16 bits, address is sent in two groups of 16 bits. This in turn has a detrimental effect on processing.
The wider the bus the more data that can be transferred simultaneously, this gives an increase in performance.

Question 19

explain how a laser printer works

Answer 19

print drum coated in a negative static
printer generates bit map of page
laser beams shine and ‘draw’ on print drum via rotating octagonal mirror
laser is modulated (turned on and off)
laser removes/reverses electric charge on drum, where image should be
toner is given negative charge
charged drum picks up toner
toner transferred from drum to paper
toner is fused/bonded/melted/stuck to paper by heated rollers through pressure

Question 20

Explain how a laser printer works.

Answer 20

Print drum coated in negative static charge
printer generates bitmap of page
laser beams shone/’draws’ on print drum via rotating (octagonal) mirror
laser is modulated (turned on and off)
laser removes/reverses electric charge on drum, where image should be dark/black
toner is given negative charge
charged drum picks up toner
toner transferred from drum to paper
toner is fused/bonded/melted/stuck to paper by heated rollers/pressure