1.1

Question 1

CPU

Answer 1

Central Processing Unit

• function is to process data and execute instructions
• measured in hertz
• 1 Hertz= 1 FDE cycle per second

Question 2

FDE cycle-fetch

Answer 2

• PC passes an address to MAR
• PC is incremented (goes up by one )
• Address in MAR is passed to memory
• Instruction is fetched from memory
• Fetched instruction is placed in MDR

Question 3

FDE cycle-decode

Answer 3

-Instruction is passed to CIR and decoded

Question 4

FDE cycle-execute

Answer 4

• The decoded instruction is then executed

- The process is repeated

Question 5

What is Von Neuman Architecture?

Answer 5

FDE cycle

Question 6

factors that affect CPU performance-Cores

Answer 6

• Cores are where FDE cycles take place
• Single core can only execute one FDE at once
• Multiple cores can execute multiple FDEs at the same time

Question 7

factors that affect CPU performance-Clock Speed

Answer 7

• Measure in Hertz (normally measured in gigahertz-1 billion)
• A measurement of the number of FDE cycles that can be completed in one second

Question 8

factors that affect CPU performance-Cache

Answer 8

• Stores frequently used data and instructions
• It’s faster to transfer to and from cache than it is from RAM
• This makes the CPU more efficient

Question 9

what else can affect performance of CPU?

Answer 9

RAM, HDD, SSD

optional-graphics card (GPU)

Question 10

Embedded System

Answer 10

A computer system built into another device and has a specific purpose e.g.

• Microwave
• Sat-Nav
• Dishwasher
• DVD player

Question 11

Describe RAM

Answer 11

Random Access Memory

• Volatile- needs power to retain data
• Stores currently used data and instructions and memory
• 1024MB=1GB

Question 12

Describe ROM

Answer 12

Read Only Memory

• Non-volatile-doesn’t need power to retain data
• Stores the boot up instructions

Question 13

Secondary Storage

Answer 13

To store data and progress e.g. operating system
-Secondary storage is persistent (Data is saved even when the power is turned off)
-Magnetic
Cheap per MB/GB (cheapest)
Large Capacity
Sensitive to movement (fragile) due to moving parts
Relatively slow to access
-Solid State
No moving parts, therefore not sensitive to
movement
Portable ,lightweight and requires less power
Relatively expensive per MB/GB
Smaller capacities than magnetic
Faster access due to no moving part

Question 14

Virtual Memory

Answer 14

• Use of secondary storage as RAM
• Stores contents of RAM
• When there isn’t enough physical space in RAM

Question 15

Developments in memory

Answer 15

• Memory clips have become physically smaller
• Whilst increasing their capacity
• Memory has become faster to access
• Memory has become cheaper per byte/kB/MB