4.7 Fundamentals of computer organisation and Architecture UPDATED

Question 1

What is the role of processor

Answer 1

primary role is to execute instructions stored in the computer’s memory

Question 2

Where does the address bus send and receive data from

Answer 2

Uni directional bus from processor to I/O or memory

Question 3

Where does the data bus send and receive data from

Answer 3

Send: CPU, Memory and I/O

Receive: CPU, Memory and I/O

Question 4

Where does the control bus send and receive data from

Answer 4

Send: CPU, Memory, I/O

Receive, CPU, Memory, I/O

Question 5

What is the role of the main memory

Answer 5

Main memory holds the data and instructions that the processor needs to access quickly during program execution

Question 6

Role of the io controllers

Answer 6

facilitating communication between the CPU and various input/output devices, such as peripherals.

Question 7

What are the three types of bus found within the cpu?

Answer 7

address buss, data bus, control bus

Question 8

What is the role of the address bus(3)

Answer 8

A pathway specifically for transmitting memory addresses.

When the CPU wants to read from or write to a specific location in memory

it sends the address of that location via the address bus.

Question 9

What is the role of the data bus

Answer 9

the pathway through which data travels within a computer system

Question 10

What determines the load capacity of the data bus

Answer 10

The width of the data bus determines how much data can be transferred at once.

For example, a computer might have a 32-bit or 64-bit data bus, meaning it can transfer 32 or 64 bits of data simultaneously

Question 11

What is the function of the control bus

Answer 11

Responsible for coordinating and controlling the various activities within the computer system.

It carries signals that indicate the type of operation being performed

It also carries timing signals to synchronize the activities of different components.

Question 12

Explain the von neumann architecure

Answer 12

• shared memory space for data and instructions in same format
• a single processor unit follows a linear fetch decode execute cycle one instruction at a time.
• registers are used for fast access to instructions and data.

Question 13

Where is the Harvard architecture system typical used

Answer 13

Embedded systems such as digital signal processing

Question 14

Where is the Von Neumann system typically used

Answer 14

Typically used in general purpose computing systems

Question 15

Explain the harvard architecture system

Answer 15

• instructions and data are stored in separate memory units
• each has its own bus
• reading and writing data can be done at the same time as fetching.

Question 16

What is addressable memory

Answer 16

Addressable memory enables the processor to read from or write to specific memory locations as needed during program execution.

Question 17

What is the stored program concept (3)

Answer 17

The idea that:

machine code instructions and data are stored in
main memory

instructions are fetched from memory and executed serially

by a processor that performs arithmetic and
logical operations.

Question 18

What is cache memory

Answer 18

Memory that can be accessed very quickly located near the processor

Question 19

How does increasing amount of cache memory improve performance of a processor.

Answer 19

• More instructions/data can be stored in the cache
• Instructions/data stored in cache can be accessed more quickly than instructions/data in main memory

Question 20

Describe the role of the control unit (3)

Answer 20

• Controls fetch execute cycle
• Synchronise operation of processor
• Control Transfer of data between registers

Question 21

What are registers (2)

Answer 21

small, high-speed storage locations within the CPU

used for storing and processing data and instructions during computation.

Question 22

What are the six types of register found in CPU

Answer 22

MAR - Memory address register
MBR - Memory buffer register
MDR - Memory data register
IR - Instruction register
PC - Program counter
Accumulator

Question 23

Explain how the Fetch-Decode Execute cycle is used to
execute machine code (7)

Answer 23

When an instruction is to be fetched the program counter contains the address of the next instruction.

The address is then copied into the memory address register

It is then sent along the address bus

Control unit sends memory read signal via control bus to the memory controller to retrieve the instruction

Contents in the correct address are transferred along the data bus.

Value from instruction goes to the CIR

Instruction in CIR is decoded by decode unit

Question 24

What is the role and operation of the ALU

Answer 24

Part of processor that performs mathematical, logical, and data processing operations.

Question 25

What is the role and operation of the Control unit within the fetch execute cycle

Answer 25

Fetch data from memory to decode them and execute them serially

Question 26

What is the role and operation of the general purpose registers

Answer 26

Can be used to hold data and instructions temporarily

Question 27

What is the role and operation of the dedicated registers

Answer 27

Used by processors to carry out a specific role

Question 28

What is the role and operation of the program counter

Answer 28

Register that holds the address of the next instruction being fetched

Question 29

What is the role and operation of the current instruction register

Answer 29

Used to store the instruction that is to be decoded and executed

Question 30

What is the role and operation of the memory address register

Answer 30

Holds the address of the current instruction being executed

Question 31

What is the role and operation of the memory buffer register

Answer 31

Holds the instruction from the MAR and the associated data

Question 32

What is the role and operation of the status register

Answer 32

Used to hold the status of various flags indicating positive results or negative result or interrupt status

Question 33

What is meant by the term ‘processor instruction set’

Answer 33

The set of machine code instructions that a particular type of processor can understand

Question 34

What is meant by opcode

Answer 34

represents the basic machine operation of the machine code instruction

Question 35

What is meant by operand

Answer 35

A value or address that forms part of a machine code instruction

Question 36

Describe the makeup of instructions

Answer 36

Consists of opcode and operand

Question 37

What is immediate addressing

Answer 37

When the data in the operand is fixed meaning it is immediately available for use

Question 38

What is direct addressing

Answer 38

Code is directly referred to a memory location

Question 39

Describe the role of interrupts and interrupt service routines (ISRs); their effect on the Fetch-Execute cycle

Answer 39

Interrupts can be generated by hardware of software when detecting an error or illegal operation. Once interrupt is generated, if it is high priority it causes the fetch execute cycle to be interrupted after completing current instruction

Question 40

Describe the Interrupt service routine

Answer 40

Interrupted task is stored - program counter contents stored in memory, current instruction finishes execution, register contents stored in memory Interrupt service routine is carried out Interrupt number examined source of interrupt identified, program counter loaded with start address for interrupt service routine which is executed. Continue Interrupted task

Question 41

What effect does multiple cores have on processor performance

Answer 41

With multiple cores, a processor can divide tasks into smaller chunks and execute them simultaneously across multiple cores. This is known as parallel processing. This will allow instructions to be carried out faster than with a single core processor

Question 42

What effect does cache memory have on processor performance

Answer 42

Cache is high speed memory fitted close to the processor, It can be accessed faster than main memory This means the speed of retrieving data instructions will be greatly increased and time taken to fetch data will reduce improving performance

Question 43

What effect does clock speed have on processor performance

Answer 43

refers to the number of cycles a CPU can perform per second, A higher clock speed means the CPU can process more instructions per second. resulting in quicker execution of tasks and programs.

Question 44

What effect does word length have on processor performance

Answer 44

performance improves with greater word length, Using a 64 bit word length with a 64 bit bus will allow 64 bits of data to be handled in one clock pulse

Question 45

what is meant by word length

Answer 45

represents the size of the data units the CPU can work with at once, has a direct effect on the processor's efficiency and the amount of data it can handle in a single cycle.

Question 46

What effect does address bus width have on processor performance

Answer 46

Affects the amount of memory that can be read from or written to When the address bus width increases, the processor can access and work with larger amounts of data stored in memory

Question 47

What effect does data bus width have on processor performance

Answer 47

data bus width directly affects how much data can be carried in one fetch operation Increased data bus width means more data can be carried in one fetch operation, allowing the processor to work faster

Question 48

Explain the need for secondary storage in a computer system

Answer 48

Avoid having to re-enter programs and data for processing by storing a permanent copy.

Question 49

operation of the barcode reader (6)

Answer 49

Operation: Scans the barcode using visible red light Light sensor measures reflected light, white areas reflect more than black creating a analogue waveform of the bar code analogue wave is converted into digital data interpreted by computer to identify product data Check digit on the end of barcode is used to ensure bar code validity

Question 50

What information do barcode lines provide (3)

Answer 50

Country of manufacturer Name of manufacturer Product code

Question 51

operation of digital camera (4)

Answer 51

Operation: Picture is taken image strikes the camera sensor Sensor records the amount of light received and converts into a digital value Image sensor records in RGB format so all other colours can be created within the image Picture is stored as image file on memory card

Question 52

Once an image has been imported to the computer which improvements can a image editing software make (4)

Answer 52

Cropping or removing of unwanted parts of the image Changing resolution Modifying brightness red eye removal

Question 53

How can pictures taken using a digital camera be transferred to a computer

Answer 53

Connecting the camera to computer via usb port Plugging the camera memory card into the computers card reader

Question 54

operation of the laser printer (5)

Answer 54

Operation: Operate one page at a time, files that require printing are sent to the laser printer using a page description language Printer processes the file and creates a bitmap pattern for the page Printer laser beam scans along and across the drum inside the printer creating the same pattern as the page this builds up a pattern of static electricity which attracts toner onto the page Toner is then fused onto paper by heat and pressure

Question 55

Advantages of laser printers

Answer 55

Print speed High quality dry page output

Question 56

What is a RFID

Answer 56

Radio Frequency Identification Tags, fixed to products which contain information similar to a barcode

Question 57

characteristics, operation and purposes of the RFID

Answer 57

Operation: RFID tags have an antenna that is used to communicate with RFID reader RFID reader transmits a radio signal which is received by the tag and a programmed information code is returned to the reader This code is then decoded and translated into digital data that is interpreted by the to computer to identify information received.

Question 58

How can RFID tags be used for security

Answer 58

Prevents theft as an unpaid item will set off an alarm when removed from store

Question 59

Advantages of using an RFID reader vs Barcode

Answer 59

RFID scanners can read multiple codes at once, which can help streamline operations. RFID systems are much more efficient for scanning a large number of items but can be more expensive and require more setup than barcodes.

Question 60

Disadvantages of using an RFID reader

Answer 60

RFID range is reduced where the tag does not have its own power source

Question 61

principles of operation of the hard disk

Answer 61

Drive consists of a number of metal disks which have been coated with a special magnetic material Disks are mounted on a spindle and rotate at high speeds A series of read/write heads move across the disk surface together to access or store the data on the disk Hard disk is mounted in a sealed unit and connected to the power supply inside the computer

Question 62

Advantages of using a hard disk drive

Answer 62

High data transfer rate High storage capacity Cheaper than SSD

Question 63

Disadvantages of Hard disk

Answer 63

Disk is fixed inside computer, making it difficult to transfer data to another computer Fragile

Question 64

principles of operation of the optical disk

Answer 64

Optical disk is a plastic disc with a mirrored surface Binary data is burned or pressed onto the surface of the disk as series of pits and lands pits have a binary value of 0 and lands a binary value of 1 laser beams are used to read the data stored on disk, since pits and lands reflect light differently, this is then decoded into original binary

Question 65

Advantages of optical disks

Answer 65

Portable cheap to produce compatible with cd or dvd

Question 66

Disadvantages of optical disks

Answer 66

scratching surface can render it inoperative less storage capacity than a hard disk slower access time than hard disk or ssd

Question 67

main characteristics, purposes, suitability and understand the principles of operation of the solid-state-disk

Answer 67

NAND flash memory + a controller that manages pages, blocks and complexities of writing. Based on floating gate transistors that trap and store charge. no moving parts, no noise, low power expensive

Question 68

SSD vs Hard Disk

Answer 68

SSD perform faster than hard drives as there are no moving parts read/write data faster SSD significantly more expensive than Hard disks and ssd tend to be smaller capacity.

Question 68

What is meant by NAND flash memory

Answer 68

The term NAND comes from the logic gate that is used to design the memory cells is a type of non-volatile storage that retains data even when power is turned off.

Question 69

Describe why fragmentation of files occurs on a hard disk drive

Answer 69

files are saved sequentially when a new or existing file is saved it may be too big to be stored in the current / next available segment so the file is broken into multiple parts / fragmented which are saved in the next available segments