Section 7 (if something is wrong please change/if there are good questions i have not asked add them in)

Question 1

What is the Processor (also known as CPU)

Answer 1

A device that carries out computation on data and instructions, in order to produce an output.

Question 2

Define Main memory

Answer 2

Stores data and instructions that will be used by the processor.

Question 3

Fetch execute cycle

Answer 3

The continuous process of data movement between main memory and the processor during the running of a program.

Question 4

Random access memory

Answer 4

Stores data and can be read to and written from, it is a temporary storage, which is quickly accessible.

Question 5

Read only memory

Answer 5

Stores data and can be read from but not written to(unless it is programmable ROM) and is not volatile.

Question 6

Data Bus

Answer 6

Transfers data between memory and processor(bi-directional).

Question 7

Address Bus

Answer 7

Used to specify a physical address in memory so that the data bus can access it.

Question 8

Control Bus

Answer 8

Controls the flow of data between the processor and other parts of the computer.(bi-directional).

Question 9

Bus width

Answer 9

The number of wires in a bus.

Question 10

Word length

Answer 10

The number of bits that can be addressed, manipulated or transferred as one unit.

Question 11

Input and output controller

Answer 11

The processor cannot directly communicate with I/O devices therefore an interface called the I/O controller handles the flow of data between the two.

Controller also behaves as a buffer as data from I/O devices are processed slower.

Question 12

Von Neumann architectures

Answer 12

A technique of building a processor that stores data and instructions in the same main memory and uses the same busses.

Question 13

Harvard architectures

Answer 13

A technique of building a processor that stores data and instruction in seperate memory and uses different busses

Question 14

What benefits are there to the two architectures.

Answer 14

pass

Question 15

State the Stored Program Concept

Answer 15

The idea that data and instructions are stored in memory together and is fetched , decoded and executed by the processor.

Question 16

List the components of the processor that allows for the fetch execute cycle to occur

Answer 16

The Control Unit
The Clock
The Arithmetic Logic Unit
Registers

Question 17

Define Control Unit

Answer 17

Part of the processor that manages the execution of instructions and makes sure data is being transmitted to the correct destination.

Question 18

Define ALU

Answer 18

Part of the processor that processes and manipulates data.

Also carries out arithmetic and logic calculations when the control unit sends it an opcode and operand to process.

Question 19

Define Clock

Answer 19

A device that generates a signal that synchronises the components pf a computer, processor and the movement of data(MHz..millions of cycles a second)

Question 20

Define Register

Answer 20

A small piece of temporary storage that is part of the processor and stores data and instructions during the fetch execute cycle

Question 21

Name the 5 registers involved in the fetch execute cycle

Answer 21

Program Counter
Memory Address Register
Memory Buffer Register
Current Instruction Register
Status Register

Question 22

Program Counter

Answer 22

A register that stores the address of the first or next instruction to be taken from main memory by the processor

Question 23

MAR

Answer 23

A register that stores the location of address that data is either being COPIED FROM or WRITTEN TOO by the processor

Question 24

MBR

Answer 24

A register that stores the data and instruction that is either being COPIED FROM or WRITTEN TOO by the processor

Question 25

CIR

Answer 25

A register that stores the instruction that the processor is currently decoding or executing

Question 26

SR

Answer 26

Keeps track of the computers various functions and the properties of data

Question 27

Define the Fetch Execute Cycle

Answer 27

The continuous cycle of retrieval of machine code and movement of data from main memory to processor while a program is being ran.

Question 28

Fetch

Answer 28

• PC set to address of first/next instruction
• Address in PC sent to the MAR
• Address of memory is transferred along the address bus into main memory
• Content of main memory is transferred through the Data Bus and stored in the MBR
• The data or instruction is stored in the CIR
• PC increments

Question 29

Decode

Answer 29

-Instruction/Data held in CIR is transferred into the Control Unit(which will execute the instruction)

Question 30

Execute

Answer 30

• If necessary data is fetched
• The opcode and Operands are sent to the ALU
• Result stored in the accumulator

Question 31

Factors affecting the performance of the processor

Answer 31

• Multiple Cores: The n amount of cores allows for n amount of instructions to be executed in one clock pulse
• Clock Speed: How fast each instruction will be executed
• Bus Width: The more wires there are in a bus more bits will be transferred in one pulse
• Cache Memory: High speed temporary memory that stores frequented data and instructions

Question 32

The Processors Instruction Set

Answer 32

A pattern of machine code that a specific processor recognises as commands

Question 33

What are the two types of instruction sets

Answer 33

Complex instruction set (CISC) and Reduced instruction set(RISC)

Question 34

Define Addressing mode

Answer 34

The way in which the operand is interpreted

Question 35

Direct Address

Answer 35

The operand is the memory address or register number

Question 36

Immediate Address

Answer 36

The operand is the datum

Question 37

Opcode

Answer 37

An operation code used in assembly language

Question 38

Operand

Answer 38

A value or memory address that forms part of an assembly language’s instruction

Question 39

what are the two types of addressing modes?

Answer 39

Immediate address

Direct address

Question 40

Translate:
IF x < 5
       THEN B = 10
       ELSE B = 11
END IF

Answer 40

CMP #5 < R1
BLT foo
B goo

foo 
    mov R2, #10
halt
goo 
  mov R2, #11

Question 41

Define Interrupt

Answer 41

A signal sent by a device or program to the processor requesting its attention.

Additional Information: Interrupts are stored in the interrupt register and each time the CPU completes one cycle it will check the interrupt register for any instructions it should do immediately before continuing with the fetch execute cycle.

Question 42

Examples of when an Interrupt signal is sent to the processor?

Answer 42

• Printer requesting for more data to be sent
• User pressing key on keyboard or clicks on the mouse
• User sending a signal asking the computer to terminate a program

Question 43

Define Interrupt Service Routine (IRS)

Answer 43

Calls the routine required to handle an interrupt

Additional Information: This routine consists of placing whatever its current task is on the fetch execute cycle and placing it on the system stack. Once the Interrupt has been processed it will retrieve the values on the stack and put them back in the appropriate registers.

Question 44

Define Priorities

Answer 44

A method for assigning importance to interrupts in order to process them in the right order.

Additional Information: interrupts on order of highest priority

1. Hardware Failure
2. Reset Interrupt
3. Program error

Question 45

Vectored Interrupt mechanisms

Answer 45

A method of handling interrupts by pointing to the first memory address of the instruction needed.

Additional Information: