CPU Structure, Function and Performance

Question 1

what happens in the fetch

Answer 1

data and instructions are fetched from main memory

Question 2

what is the address bus

Answer 2

this transmits memory addresses specifying where data is to be sent to

Question 3

what is a data bus

Answer 3

used or transporting data and instructions between components

Question 4

what happens in the decode stage

Answer 4

this is where the the fetched instruction is decoded

Question 5

execute phase

Answer 5

this is where the decoded instruction is executed

Question 6

control units

Answer 6

controls the activities of the CPU and the flow of data

Question 7

what does the clock speed mean

Answer 7

time taken for one clock cycle to complete

Question 8

what does CPU cores allow u to do

Answer 8

allows multiple instructions to be processed at the same time

Question 9

what is pipelining

Answer 9

where the output of one stage is the input for another

Question 10

what is the Harvard architecture

Answer 10

where the programs instructions are stored separately in memory

Question 11

what are the disadvantages of the Harvard architecture

Answer 11

memory is not dynamic as one half is used for data and the other for instruction

Question 12

what are the advantages of the Harvard architecture

Answer 12

quicker execution as data and instructions can be fetched in parallel

Question 13

what is CISC

Answer 13

complex instruction set computers, can execute many instructions in only one line of code

Question 14

what is RISC

Answer 14

reduced instruction set computers, can only execute one line of code at a time

Question 15

what is an example of a parallel system

Answer 15

a GPU it has lots of different processors which work in parallel to complete repetitive tasks

Question 16

Current instruction Register

Answer 16

holds the current instruction being executed by the CPU

Question 17

what does the MAR do

Answer 17

holds the address of the location that is to be fetched from memory

Question 18

what does the MDR do

Answer 18

holds the data that has been read or data that has to be written

Question 19

what does the PC do

Answer 19

holds the address of the next instruction to be executed

Question 20

what does the PC do

Answer 20

holds the address of the next instruction to be executed

Question 21

what are buses

Answer 21

parallel wires which connect components inside the CPU

Question 22

what happens in the fetch relating to registers

Answer 22

address from the PC is copied to the MAR

Question 23

what happens in the decode relating to registers

Answer 23

the contents in the CIR are split into operand and opcode

Question 24

what is the difference between level 1 cache and level 3

Answer 24

level1 cache is faster than level 3

Question 25

what are the advantages of von neumann architecture

Answer 25

it is cheaper to develop as control unit is easier to design programs can be optimised in size

Question 26

what are the advantages of the Harvard architecture

Answer 26

quicker execution as data and instruction can be fetched in parallel memories can be different sizes which can make more efficient use of space

Question 27

what does the GPU do with respect to its processors

Answer 27

graphics processing unit which contains lots of different processors working in parallel making it very efficient to complete various REPETITITVE TASKS (image processing)

Question 28

why is pipelining possible on the RISC processor

Answer 28

it is possible since each instruction takes one clock cycle and it is simpler to execute therefore they can processed in parallel

Question 29

what is the difference between parallel systems and multicore systems

Answer 29

multicore systems use multiple cores to process instruction in parallel parallel systems ONLY USE 1 core to process tasks simultaneously

Question 30

what is the purpose of the CU

Answer 30

synchronizes data transfer between registers