Topic 3 Flashcards
(109 cards)
1
Q
What is the CPU
A
central processing unit.most important hardware component in a computer.
2
Q
what is inside the CPU
A
ALU, CU, registers (MDR,MAR,CIR) , ACC, PC, cache
3
Q
two main features of CPU
A
: to process data and instructions. to control the rest of the computer system.
4
Q
what is the Von Neuman Architecture
A
the design upon which many general purpose computers are based
5
Q
main features of Von Neuman Architecture
A
-CPU able to access memory directly
-computer memories couls store programs as well as data.
-stored programs were made up of instructions which could be executed in sequential order
6
Q
components of CPU
A
control unit (CU)
Arithmetic and logic unit(ALU)
registers and buses
7
Q
what does the system clock do
A
keeps in time all components of CPU
8
Q
what does the CU do
A
reads instruction form meomory, which is thgen interpreteted using the FDE cycle
coordinates and controlls all operations that are carried out
9
Q
What does the ALU do
A
allows the required arithmetic and logic operations to be carried out while program is run
10
Q
eg of arithmetic operations and logics
A
arith. addition or substraction
log. smaller, grater equal
11
Q
what are registers
A
small amounts of high speed memory contained within the CPU
12
Q
what is storedin registers uring processing
A
address of next instruction to be executed
current instruction being decoded
results of calculations
13
Q
MAR
A
memory address register, stores the address of memory location currently being read from or written to
14
Q
MDR
A
memory data register
stores data which has just been read from memory or data which is about to be written to memory
15
Q
PC
A
program counter
stores the address where the next instruction to be read can be found.
its value change once an instructions i fetched, it is incremented by 1
16
Q
ACC
A
accumulator
used when carrying out ALU calculations, stores data temporarily during this calc.
17
Q
what is a bus
A
high-speed internal connection, used to send control signals and data between the processor and other components
18
Q
address bus
A
carries memory address from processor to other components(primary mem, input/output devices)
19
Q
Control bus
A
carries control signals from the processor and carries the clock’s pulses
20
Q
data bus
A
carries actual data
21
Q
primary storage memory
A
RAM,ROM
22
Q
RAM
A
main memory, random access memory, access to it very fast, volatile
23
Q
ROM
A
read only memory
data permantly saved, non-volatile
holds firmware, bootstrap instuction and BIOS
24
Q
3 operations operated by CPU
A
fetch= fetched data from memory and stores them in suitable registers
decode
exexute
25
FDE cycle in details
fetch= address of an instruction in the PC is fetched from RAM
decode= this instruction is decoded by CU
execute= fetched data from memory, jumps to another instruction and writes data back to RAM
26
clock speed
frequency of pulses, number of cycles per second, higher frequency more instructon can be performed.
Clock sens out a regular electrical pulse that keeps in time all components.
3.2 GHz
27
what is consequence if CPU gets overclocked
instability and damage to the processor
28
what is a core
single complete copy of CPU, processor
Can improve performance by processing 2 instructions at simultaeously.
29
uses of single,dual,quad core CPUs
1 instructuon at time
basic tasks, word processing, browsing
gaming performance (4 seperate processing units)
30
what is cache
very fast memory locate dwithin the CPU, temporary storage of data from RAM
the larger the cache size the better the CPU performance
provides data and instructions frequently used without having to go to RAM
31
operations that instruct ALU and CU
opcode= tells processor the job that need to be done
operand=specifies the data that needs to be acted on
32
what is an embadded system
small computer that forms part of a larger system, device or machine
33
purpose of embadded systems
control the device and allow a iser to interact with it, allow devices to perform specific functions
34
examples of embadded systems
GPSs systems, fitness trackers, smart watches, mobile phones, dishwashers, TVs and central heating systems
35
what can embadded systems be based on
microcontrollers(CPU and some RAM and ROM on single chip)
microprocessor (integrated circuit with only CPU on chip)
Soc (system on chip) =may contain a microcontroller as one of its components
36
what do machines have for controlling all tasks in embadded systems
microprocessor, user only needs to input limit amount of info and press buttom
37
can embeadded systems be programmed by a user
they can't but it is possible to upgrade software(eg fitness trackers can be upgraded by connecting device to a pc and installing the new software
38
benefits of embadded systems
small in size
low cost to make
-require little power
-can be controlled remotely
-simple interfaces
-very fast reaction to changing input
39
drawbacks of emadded systems
-can be difficult to upgrade
-the interface can appear simple but ic cann be confusing
-open to hackers as any device connected to internet is
40
embadded in security
alarm activated using keypad and security code is set in RAM. data from sensors is sent to controller checking against values stored is SSD. output can be lights, message, sound incase of values being different. owner can interface the system remotely if necessary.
41
what is data storage
how info is kept in a digital format to be accessed again later
42
primary memory
RAM, ROM
43
internal secondary storage
SSD,
HDD
44
External secondary storage
DVD7CD &DVD-RAM, BLUE-RAY DISC, USB memory stickm Removable hard drive
45
Features about primary memory
directly accessable by CPU
contains RAM, ROM and Cache memory
allaws CPU to accessapplications and services temporarily stored in memory locations
46
Features about secondary storage
non directly accessable by CPU
ALL are non-volatile
can be external or internal to the computer
can store more data but data access is shorter
47
types of secondary storage
magnetic
optical
solid state
48
what is magnetic storage
mechanical parts move over the disk surface to read and write data magnetically
49
magnetic disks features
has concentric circles called tracks divided into sectors
50
HDD
Hard disk drive- magnetic storage
built in PCs and laptops
large storage capacity
it can be portable(via USB port)
used for backing or transporting data
51
advantages of magnetic
cheap
vast storage capability
fast write speed
52
disadvantages
and capacity of magnetic
durability an issue, lots of mechanical parts
500 GB - 6 TB
53
what is opticl storage
lasers read and write data using light
54
how is data stored in optical
laser is shone at disk pits and lands
laser burns pits into surface
laser used to read pits and lands on surface
the reflected light is captured by a sensor
55
adv in optical storage
cheap, very easily portable, takes up little space physically
56
disavantages, uses and in optical
less storage capacity, easily damaged, requires CD reader, slow write speeds
songs, videos and other multi-vdia storage, backup and archiving of data
57
capacity of optical
CD to 720 MB, DVD 84GB, BLUE-RAY 50GB
58
how does blue-ray work
uses blue laser to carry out operations, pits and lands are smaller so high definition
59
What is SSD
solid state drive
data recorded onto solid memory chips
replaced traditional HDD
60
examples of SSD
SD card, USB flash memory drive
61
how does SSD work
no moving parts all data is retrived at the same rate, don't rely on magnetic properties
62
features of solid state disks
uses non-volatile flash memory
very fast burst read/write speeds
63
advantages of SSD
highly durable, no moving parts, no noisy fan, faster start up times
64
Disadvantages of SSD
expensive, lss storage capacity
65
uses and capacity of SSD
portable computers, military usage
100 GB- to 16 TB
66
how does flash memory work
large electric current used to force elecetrons through a barrier and trap them on the other side
they remain on other side until flashed with new current,
trapped (charged) or not trapped=0 or 1
67
uses andadvantages and of flash memory
+low cost, durable, portable, no moving parts
-offline deviced (cmeras, iphone, USB memory stick)
68
Virtual memory
uses senables computer to compensate for physical memory shortages, temporarily transferring data from RAM to disk storage
69
virtual memory allows to treat secondary memory like
the main one
70
what to do if RAM is exceeded
a system crush is likely to occur, so the solution is to use hard-disks or SSD if we need more memory
71
benefits of virtual memory
-more applications to be used at once
-increased security because of memory isolation
-data con be moved automatically
-increased speed when onlly a segmentof program is needed for execution
-saves user from having to add additional memory modules
72
what is cloud storage
method where data is stored on remote servers over the internet, saved in more than 1 server so that user can access it at any time from anywhere with an internet connection(called data redundacy)
73
benefits of cloud storage
-unlimited storage capacity
-can be accessed from anywhere at anytime
-no need to carry external storage device for user or same computer
-provides user with remote backup of data
74
drawbacks of cloud storage
if internet connection is slow, probelms accessing
-costs can be high
-potential failure of cloud storage company is possible, risk of loss of data
-requires internet connection
-data actually need to be contained in whare houses and servers that can tale up vast amount of space.
75
differences between public cloud and private cloud
public=is cloud computing that's delivered via the internet and shared across organisations
private=is cloud computing that is dedicated solely to your organisation
in schools we use private, companies that need to store sensitive data use private
76
what is data redundancy
Data redundancy is created within a database when the same piece of data is held in several places
77
NIC
network interface card
needed for devices to connect to network
circuit board installated in the device hardware, contains MAC
78
what are WNICs
antenna used to communicate with networks via microwaves
79
what is MAC
media access control
unique serial number assigned to each NIC
80
what does MAC do
allows a network to identify any device
-identify the sender's and the recipent's devices when pack of data is sent/received
81
characteristics of MAC
written as hex
- created using manufacturer code and serial code
- -48 bits, gropus of 6 hex
82
2 types of MAC
UAA=Universally administered MAC address
LAA=locally administered address
83
IP address
internal protocol
unique number assigned to your device in a network(only on that nework)
84
types of IP addresses
static or dynamic
85
bits of IP
32(IPv4) or 128 bits (IPv6)
86
what happen if router conncets to internet
given a unique public Ip address supplied by ISP( internal service provided)
87
features about static IP
assigned manually by ISP, doesn't change
ideal for hosting computer servers, fcilitates faster data exchange
difficult to set up and manage, more expensive, vulnerable to hacking
88
Dynamic IP features and pross
temporary, may chnage when you reboot your system or router.
assigned by ISP via a DHCP server
automatically configured, cost-effective, less prone to hacking
nearly impossible to set up remote access, can cause downtime when disconnected, affects performance of geolocation devices
89
disadvantgaes of dynamic IP
nearly impossible to set up remote access,
can cause downtime when disconnected,
affects performance of geolocation devices
90
what does a router do(main)
sends data to a specific destination on a network, designed to receive, analyze and forward data packets to computer networks
91
features of routers
-can connect a local network to the internet
-can assign a local IP address to each device on a netowrk
-manages traffic on network
-creates a firewall to prevent security breaches
92
how does a router allow different networks to communicate
by converting the data to a protocol and format undesrstood by the other network
93
what does the same part of IP address allow the router to do
send data packet to correct node and thorugh MAC address data will be delivered to the right device
94
what does the same part of IP address allow the router to do
send data packet to correct node and thorugh MAC address data will be delivered to the right device
95
examples of input devices
keyboard, digital camera, barcode/QR code scanner, microphone, optical mouse,touch-screen, 2D/3D scanners, sensor, interactive white boards
96
different types of touch screen
capacitive, infrared, resistive
97
advantages and dis. of capacitive
multi-touch allowed, good image clarity, high scratch resistance
only work woth bare fingers/stylus, sensitove to electromagnetic radiation
98
adv dis of infrared
allow multi-touch, good screen durability, operability isn't affected by cracked screen.
sensitive to water and sometimes to light interference
99
adv dis resistive
good resistance to dust+water, can be used with stylus, fingers, gloved hand.
low-touch sensitivity
no multi-touch, vulnerable to scratches, poor visibility on strong light
100
how are key presses processed by computer
A key is pressed that presses a switch, location of key press is calculated.
ASCII value has binary value.
binary value can then be processed by CPU to action key press
101
examples of output devices
actuator, DLP projector, inkject printer, laser printer, LED screen, LCD projector, LCD screen, speaker, 3D printer
102
adv dis DLP (digital light processing projector)
high reliability, quiet, small+light,high contrast ratios
colour definitio is not as good, image suffers from shadow, no grey components in image
103
adv dis LCD (liquid crystal dislplay projector)
give sharper images, better colour saturation, generate less heat
contrast rations aren't as good, limited life, screens tun yellow with time
104
inkject printer advaneges and dis compared to laser printers
less expensive, more people can afford them,
resolutions isn't as good. lower quality
105
LCD (liquid cristal display) Screen
Low power consumption and low heat production
sharp image with more realistic colours
LEDs last for an extremely long time, this increases reliability
LEDs are smaller so screens can be thinner (Good for mobile devices)
106
OLED ( Organic Light Emitting Diode) adv dis
much lower power consumption, (Less electricity required), thinner and lighter
drawabacks dont last as much, more expensive
107
speaker, how it works
data is sent from the computer to a DAC (Digital to analogue converter), this creates the analogue signal which is sent to an amplifier which then creates the actual sound.
108
magnetic door sensor
detects if a magnet moves
away from its sensor – used on doors and windows
109
sesnsors
infra-red(detect motion), light, temperture, acustic, sound, smoke detector, pressure (cars)
