(UNIVERSAL SERIAL BUS)(UNIVERSAL SERIAL BUS)
Presented by : Shehrevar Davierwala
Contact : firstname.lastname@example.org
What is USB?
History of USB….
Features of USB….
Features of USB cable.
Version of USB.
Location of USB ports.
What uses USB ports
USB pen drives..
Best five uses pen
What is USB?
USB is know as Universal Serial Bus.
It is used to transfer data from one
device to another.
Basic architecture of USB is host-to-device
connection and transaction.
History of USB
It was first invented by Iseraeli company called
‘M-system’ and the brand is called ‘Disk on key’.
USB was released by no.of companies including
Many companies claimed to have invent the usb
storage device but M-system was the one to get
the patent in 2000.
Features of usb
Attachment is detected and device is configured
Single standard connector.
127 devices can be connected via hubs.
Three device speeds:
Power: 5V, 100mA-500mA
Error detection/recovery is automatic
D+ =Signal Line
D-= Signal Line
VBUS = Power
Supply5.25V to 4.2V
VGND = Ground
Signal Lines are twisted
Features of USB cable…
The maximum cable length is five meters orapproximately 15 feet.
The cables contain fourwires. Power, Ground, Data Plus (D+) and
Data Minus (D-). D+ and D- forma differential pair.
The powerline is +5VDC.
The usb connectors are of two types called A connectors
The A connectoris rectangularand the Bconnectorhas a
more rounded type mechanical structure.
There are also mini A, mini B, and mini ABconnectors
which are smallerspecial versions of the A and B
Types of connector
Versions of USB
USB1.0 FDR: Released in November 1995.
USB1.0: Released in January 1996.
USB1.1: Released in September 1998.
USB2.0: Released in April 2000. The
major feature of this standard was the
addition of high-speed mode. This is the
USB2.0: Revised in December 2002.
USB system consist
of three units
1] USB host
2] USB Cable
3] USB DeviceHost Device
When a device is attached, the OS
“enumerates” the device, identifies its driver,
and assigns an address to it.
In the enumeration process, data
structures (transfer descriptors) contain
information needed by the host to generate
transactions. This information includes:
USB device address.
Type of transfer.
Direction of transfer (write or read).
Transfer size (# of bytes).
Address of the device driver’s memory buffer
The host controller initiates and manages all USB
A USB transfer consist of one or more transaction and
each transaction contains up to three packets.
There are 3 types of packets
1] Token 2] Data 3] Handshake
Each packet contains packet ID block of information and
error checking codes.
PC USBPorts…where are
Front of PC…built in
Backof PC…built in
Add-On card installed
A USB“Hub” installed
USB ports…. Front of PC…built
USBports…. Rear of PC…built
USB ports….connected to
USB ports…add on card
USB ports…Laptop PCMCIA
It is used to add
memory or credit
card size peripheral
USB ports…USB Hub
USB ports…What can use
Printer, Scanner, Keyboard, Mouse
Drives…Hard, Floppy, CD, Zip, Flash Drives
Wireless…”Bluetooth”, Keyboard, Mouse
Flash memory cards…Card Readers
Hubs…up to 127 Ports useable
USB Pen Drives (flash drive)
USB flash drive was invented by Dov Moran.
Ajay Bhatt of Intel was the co-inventor.
Pen Drive is a latest invention in USB which
help us in many ways as it help to store your
precious data safely and to transfer it from one
place to another.
Best Five uses of a pendrive
1 Transferring files from one PC to another.
This will of course be limited to the size of
the Pen drive, but with sizes higher than 32
GB now available. This is the first use
anyone will put a pen drive into.
2 As a small backup solution. You can install
Windows XP or vista , to a USB pen drive.
So if for any reason you can’t boot to
Windows, you can still boot to an installation
of Windows, plug in an external hard drive
and take off any information from the hard
drive before formatting.
3 As temporary RAMin Vista. In Windows Vista,
ready boost allows you to allocate a pen drive
as RAM. Microsoft has introduced a new
technology called ReadyBoost. With the help
of this technology one can use any Flash
drive, SD Cards as the third memory option for
In order to activate the ReadyBoost technology on
your FlashDrive or Memory Cards, you have to
follow these steps…
1. Open My Computer.
2. Right Click on the Removable Disk Drive
and select Properties.
3. Click on Ready Boost Tab.
4. Enable the feature by selecting the option and
allocate the amount of space you want to use as
Things to be noted….
1. Regardless of the fact that you use Readyboost
or not, you need at least 512 Mb of memory to run
Windows Vista decently.
2. If your device is not giving the option of
ReadyBoost then it means that it doesn’t clear up
the minimum data trasfer rate required by Read
The benefits of Flash Drive or Pen drive as a
source of Memory :
1. It is faster than the virtual memory which is
accessed through the hard disk drive.
2. It is cheaper as compared to the actually
4.Portable applications. You can carry
many portable applications on your Pen
drive. eg: Mozilla thunderbird.
5.Booting to LINUX
Installing a Linux distro to a pen drive
will allow for the use of the hard drive and
all the files on it.