slr1 - Structure and function of the CPU

Question 1

What is the role of the control unit

Answer 1

Controlling and coordinating the activities of the CPU
Managing the flow of data between the CPU and other devices
Accepting the next instruction
Decoding instructions
Storing the resulting data back in memory

Question 2

Which register Accepts the next instruction and decodes it

Answer 2

Control unit

Question 3

What is stored in the program counter

Answer 3

The address of the next instruction in memory that the processor needs to execute

Question 4

At the start of every fetch decode execute cycle where is the address in the PC copied to

Answer 4

The Memory Address Register

Question 5

What is stored in the MAR

Answer 5

The address of the memory location data or instructions are to be read from or written to memory

Question 6

Which register sends addresses to memory

Answer 6

MAR

Question 7

Which bus only transfers data in one direction

Answer 7

Address

Question 8

What is the role of the address bus

Answer 8

Transmits memory addresses from the processor to other parts of the system

Question 9

What is stored in the MDR

Answer 9

Data which is read from or written to memory

Question 10

What can the MDR also be called

Answer 10

“Memory Buffer Register” or “the gateway to the processor”

Question 11

Where must all data going to and coming from memory pass through

Answer 11

The Memory Data Register

Question 12

Which bus is responsible for transferring data to and from memory

Answer 12

Data Bus

Question 13

Name the three buses

Answer 13

Control
Address
Data

Question 14

What is held in the CIR

Answer 14

The current instruction being executed

Question 15

If the data stored in the MDR is an instruction where is it copied to

Answer 15

The CIR

Question 16

What is stored in an instruction

Answer 16

Opcode and Operand

Question 17

What is opcode

Answer 17

The instruction being executed

Question 18

What is the Operand

Answer 18

Which address in memory to execute it on

Question 19

What is the role of the ALU

Answer 19

Performs arithmetic and logical operations on data

Question 20

What are the 3 types of operation

Answer 20

Arithmetic
Bitwise
Boolean logic

Question 21

what are bitwise operations

Answer 21

Operations that manipulate the individual bits of binary data

Question 22

What is stored in the accumulator

Answer 22

The result of calculations carried out by the ALU

Question 23

What is the role of general purpose registers

Answer 23

They temporarily store data within the CPU

Question 24

What is the role of the control bus

Answer 24

Sends command and control signals to and from every component of the computer

Question 25

What is carried by the data bus

Answer 25

The actual 1s and 0s that make up the information being transmitted around the CPU

Question 26

What is the role of the decode unit

Answer 26

Prepares the execution of an instruction by looking up the binary operation code

Question 27

What is the stored in the status register

Answer 27

Information about the status of the CPU

Question 28

What is the role of the clock

Answer 28

Synchronises components by generating pulses at a fixed rate

Question 29

What are the 3 main factors affecting the speed of a CPU

Answer 29

Clock speed
Cache size
Number of cores

Question 30

How does clock speed affect the speed of a processor

Answer 30

higher clock speed means more FDE cycles per second

Question 31

Why does cache size affect processor speed

Answer 31

A larger cache means that the cpu can have faster access to more instructions

Question 32

What is cache

Answer 32

Small memory located on or near the CPU that temporarily stores data and instructions for faster access

Question 33

Why is cache better than main memory

Answer 33

Cache is faster to access

Question 34

describe a core

Answer 34

A complete copy of a CPU that contains all of the necessary registers

Question 35

Why does the number of cores affect performance

Answer 35

CPUs with more cores have more power to run multiple programs at the same time

Question 36

Why does doubling the number of cores not double the performance of a CPU

Answer 36

CPU cores have to communicate with each other
Many programs aren’t designed to use multiple cores

Question 37

Describe the difference between a CMP and a CPU

Answer 37

A CMP houses multiple CPU cores

Question 38

What does CMP stand for

Answer 38

Chip Multiprocessor

Question 39

Describe the Von Neumann architecture

Answer 39

Shared memory for instructions and data
Instructions and data are stored in the same format
Each processor follows a liner fetch decode and execute cycle
One instruction at a time
Registers are used for fast access to instructions and data

Question 40

Describe the Harvard architecture

Answer 40

Instructions and data are stored in separate memory units
Each of which has its own bus
Reading and writing can be done at the same time as fetching an instruction
Used by RISC processors

Question 41

How do contemporary architectures differ from older architectures

Answer 41

They can make use of SIMD and MIMD

Question 42

Describe SIMD

Answer 42

Where the processor uses parallel processing to carry out a single instruction on multiple items of data at the same time

Question 43

Describe MIMD

Answer 43

Another version of parallel processing where multiple instructions are carried out on different data items across multiple cores

Question 44

What is distributed computing

Answer 44

Where multiple computers on a shared network each take on part of a larger problem

Question 45

What is a register

Answer 45

Small memory units that operate at a very high speed

Question 46

What are the 6 instruction that can be sent down buses

Answer 46

Request
Grant
Memory write
Memory read
Interrupt request
Clock