1.1 The characteristics of contemporary processors, input, output and storage devices

Question 1

What does the ALU do?

Answer 1

The arithmetic and logic unit performs all arithmetic and logic calculations.

Question 2

What does the CU do?

Answer 2

The control unit coordinates the activities of the CPU.

Question 3

What are the names of the five registers?

Answer 3

Program counter (PC), Accumulator (ACC), Memory Address Register (MAR), Memory Data Register (MDR) and Current Instruction Register (CIR).

Question 4

What does the Program Counter do?

Answer 4

Holds the address of the next instruction to be executed.

Question 5

What does the Accumulator do?

Answer 5

a register that stores logical and arithmetic data in multistep calculations temporally.

Question 6

What does the MAR do?

Answer 6

The Memory Address Register holds the address of the instruction being fetched from/ sent to memory.

Question 7

What does the MDR do?

Answer 7

The Memory Data register temporarily stores the data being fetched from/ sent to main memory.

Question 8

What does the CIR do?

Answer 8

The Current Instruction Register holds the instruction currently being executed (divided into operand and opcode)

Question 9

What does the Operand ( in the CIR) contain?

Answer 9

Codes the address of the. data which the operation is to be performed.

Question 10

What does the Opcode ( in the CIR) contain?

Answer 10

The type of instruction to be executed.

Question 11

What are the three system buses?

Answer 11

Address, Data and Control bus

Question 12

What is a Bus?

Answer 12

a set of parallel wires which connect two or more components in the CPU.

Question 13

How is a Buses’ width related to the number of bits transferred?

Answer 13

width of bus is directly proportional to the number of bits transferred

Question 14

What is the Address bus?

Answer 14

a unidirectional bus, that passes the address of the instructions from CPU to the Ram.

Question 15

What is the data bus?

Answer 15

a Bi-directional bus that carries data to and from the address held on the address bus.

Question 16

What is the Control bus

Answer 16

a unidirectional bus that carries control signals from processor to other components (carries clock pulses)

Question 17

What is the fetch-decode-execute cycle?

Answer 17

A sequence of operations that are completed in order to execute an operation.

Question 18

What happens in the fetch stage of the fetch execute cycle?

Answer 18

• The address is copied from the PC to the MAR.
• The instruction held in that address is copied to MDR by the data bus.
• Contents of PC increased by 1
• value held in MDR is copied into CIR

Question 19

What happens in the Decode stage of the fetch-execute cycle?

Answer 19

The contents of CIR are split into Operand and Opcode.

Question 20

What happens in the Execute stage of the fetch-execute cycle?

Answer 20

The Decoded instruction is executed.

Question 21

What are the three factors that affect the processor?

Answer 21

Clock speed, Number of cores and Cache size.

Question 22

What is the System Clock?

Answer 22

it controls the clock speed with signals of 1s and 0s. the activities start on the clock pulse ( when 0 switches to 1)

Question 23

What is the Clock speed?

Answer 23

The time it takes for one clock cycle to complete. the faster the clock speed the more clock cycles completed in a given space of time.(measured in hertz)

Question 24

What is a Core?

Answer 24

a independent processor that is able to complete its own fetch-execute cycle.

Question 25

Whats the benefit of having multiple cores?

Answer 25

more fetch-execute cycles can be completed at one time.

Question 26

Whats the drawback of having multiple cores?

Answer 26

Not all programs are able to work with multiple cores.

Question 27

What is the Cache?

Answer 27

a type of memory stored within the CPU that temporarily stores frequently used instructions.

Question 28

What is the benefit of having a large cache?

Answer 28

It takes less time to collect data from the cache then the RAM.

Question 29

Whats the difference between the three types of Cache?

Answer 29

The first level is the fastest with the smallest capacity and the third is the slowest with the largest capacity.

Question 30

What is pipelining?

Answer 30

The process of completing the fetch, decode and execute cycles of three separate instructions simultaneously.

Question 31

What are the two types of pipelining?

Answer 31

Instruction and arithmetic pipelining.

Question 32

What is instruction pipelining?

Answer 32

Separating the instruction into fetching decoding and executing.

Question 33

What is Arithmetic pipelining?

Answer 33

breaking down the arithmetic operations and overlapping them as they are performed.

Question 34

What is the downside of pipelining?

Answer 34

programs with a lot of selection ,as some lines will be fetched and decoded when they are not needed.

Question 35

What is Von Neumann Architecture?

Answer 35

an architecture of the cpus components that share data and programs in the same registers and carry the on the same buses.

Question 36

Where is Von Neumann architecture commonly used?

Answer 36

In conventional processors in PCs.

Question 37

Whats the benefits of Von Neumann Architecture?

Answer 37

its cheaper to develop and allows programs to be optimised in size.

Question 38

What is Harvard Architecture?

Answer 38

an architecture that has two physically separate memories for instructions and data.They are transferred in parallel buses making for quicker execution

Question 39

Where is Harvard architecture commonly used?

Answer 39

often used in embedded systems

Question 40

What are the benefits and drawbacks to harvard architecture?

Answer 40

Benefit- efficient use of space Drawback- programs tend to be large

Question 41

What is Contemporary processing?

Answer 41

A processor that uses a combination of Harvard and Von Neumann architecture. Harvard in the cache; Von Neumann in the main memory.

Question 42

What does RISC stand for ?

Answer 42

Reduces instruction set computing

Question 43

Where are RISC processors most often used?

Answer 43

in smartphones and tablets.

Question 44

What does CISC stand for?

Answer 44

Complex Instruction Set Computing

Question 45

Where are CISC Processors most often used?

Answer 45

in Laptops and Desktop computers

Question 46

Compare the Hardware of RISC and CISC Processor.

Answer 46

CISC has more complex hardware; RISCC has less complex hardware

Question 47

Compare the machine cycles of RISC and CISC processors

Answer 47

CISC has multiple machine cycles per instruction; RISC only has one per instruction.

Question 48

Compare the energy consumption of CISC and RISC processors

Answer 48

CISC has a greater energy consumption; RISC has a lower energy consumption.

Question 49

Which processor would more intensive tasks be more efficient with, Out of RISC and CISC?

Answer 49

CISC (RISC is better/quicker at simpler tasks)

Question 50

Which architecture can address memory in more ways?

Answer 50

CISC

Question 51

Compare the physical size of CISC and RISC processors.

Answer 51

CISC is physically larger and more expensive; RISC is smaller and cheaper

Question 52

Why is a RISC processor cheaper?

Answer 52

its smaller so requires less silicon

Question 53

What is a GPU?

Answer 53

the graphical processing unit is a device with multiple independent processing units which work in parallel

Question 54

Why are GPUs useful?

Answer 54

they are efficient at completing repetitive tasks such as image rendering and machine learning.

Question 55

What is threading?

Answer 55

it refers to concurrent execution of multiple threads within a single process

Question 56

What are threads?

Answer 56

individual sequences of instructions that can run independently but share the same resources, including memory space , within a process.

Question 57

What are Multi-core processors?

Answer 57

Processors with multiple independent cores that can complete instructions separately.

Question 58

What are Parallel processing systems?

Answer 58

processors that complete tasks in a single core using threading

Question 59

Which of parallel systems and multi-core cpus perform better in larger projects?

Answer 59

multicore systems perform better

Question 60

What is an input decive?

Answer 60

a device which can be used to put data and information into a computer

Question 61

What is an output device?

Answer 61

a device which can be used to send information from the computer

Question 62

Give some examples of input devices.

Answer 62

Keyboard; Webcam; Magnetic stripe reader; barcode reader and digital cameras

Question 63

Give some examples of output devices.

Answer 63

LCD monitors; Organic LED monitor; speakers; printers; projectors ;and actuators

Question 64

What are the three types of secondary storage?