Processor fundamentals

Question 1

ALU

Answer 1

Requires arithmetic or logic operations to be carried while being run. It is a the arithmetic logical unit of the computer which does all the mathematical functions

Question 2

CU

Answer 2

Reads the instruction from memory, the instruction is interpreted. Signals are generated along the control bus to tell the computer what to do

Question 3

System clock

Answer 3

to coordinate / synchronise the actions of other components in the CPU
* to send / receive control signals along the control bus
* to manage the execution of instructions (in sequence)
* to control the communication between the components of the CPU

Question 4

CIR

Answer 4

Holds the op code and operand of an
instruction ready for it to be decoded

Question 5

MAR

Answer 5

Holds the address where data is to be
written to or read from

Question 6

MDR

Answer 6

Holds data read from, or to be written to,
memory

Question 7

PC

Answer 7

Holds the address of the next instruction to
be read

Question 8

ACC

Answer 8

Holds the result of the last instruction
executed by the ALU

Question 9

IX

Answer 9

to store a value that is added to an address to give another address

Question 10

Status register

Answer 10

to store flags which are set by events // from the results of arithmetic and logic operations and interrupt flags

Question 11

MU

Answer 11

Holds flags that are set when the Arithmetic
and Logic Unit (ALU) executes instructions

Question 12

Fetch Execute cycle

Answer 12

[PC]—-> MAR
[MAR] —-> [MDR]
[MDR]—->[CIR]
PC<—- [PC] +1

Question 13

Address bus

Answer 13

Unidirectional, between CPU and memory of the address bus. Prevents addresses being carried back to the CPU
width is important wider the bus more memory locations it can address at any given time

Question 14

Data bus

Answer 14

Bidirectional, allows data to be sent in both direction. Carries out data from CPU to memory. Data can be an address or a instruction or numerical value.

Question 15

Control bus

Answer 15

Bidirectional carries signals from CU to other parts of the computer.

Question 16

What affects Computer speed

Answer 16

Width of busses
Clock speed
Cache memory
No. of cores

Question 17

Overclocking

Answer 17

Clock speed can be changed by going into BIOS. Using a higher clock speed leads to problems.
* An instruction will not be complete with the given amount of time, so the computer will frequently crash and become unstable.
* Overheating of the CPU

Question 18

Cache memory

Answer 18

Improves processor performance. Uses RAM, memory gets lost after no power is supplied. Uses SRAM, there is no need to keep refreshing as it slows down access time
It stores frequently used data and instructions that need to accessed faster.

Question 19

Cores

Answer 19

A core is made up of a ALU, CU and registers. CPU is made up of two cores - dual cores. quad cores - 4 cores.
Using more cores increases clock speed, BUT they do not always increase a processors speed.
Dual cores increases speed - one channel, needs CPU to communicate with both cores
Quad cores decreases speed - 6 channels too many channels, CPU overworks, reduces speed

Question 20

USB ports

Answer 20

Universal serial Bus - detects that a device is present due to the change in the voltage level.
Device is recognized and the device driver is loaded, so that it can communicate with the device

Question 21

HDMI

Answer 21

Supports high definition signals.
Widescreen format
Uses a greater number of pixels when compared to VGA
Screens have a faster refresh rate.
Large range of colors

Question 22

Pros and cons of HDMI

Answer 22

Pros - standard for modern television
fast data transfer
improved security
modern digital system
Cons - not robust
breaks the connection by just moving the device
limited cable length

Question 23

Pros and cons VGA

Answer 23

Pros - Simpler technology
only on standard
easy to spilt and signal
connection is secure
Cons - Old out dates analogue tech
easy to bend the pins
cables must be very high grade

Question 24

Interrupts

Answer 24

Interrupt signal appears
checks priority
Status of the tasks that were running are saved.
Interrupt service routine is executed.
Interrupt is serviced, task continued from its prior point

Question 25

Indirect addressing

Answer 25

the address to be used is at the given address

Question 26

Relative addressing

Answer 26

the address to be used is an offset number of locations away, relative to the address of the current instruction

Question 27

Indexed addressing

Answer 27

form the address from the given address plus the contents of the index register

Question 28

Opcode

Answer 28

The opcode is the instruction that is executed by the CPU

Question 29

Operand

Answer 29

Data or memory location used to execute that instruction