UNIVERSAL SERIAL BUS

Introduction

Universal Serial Bus (USB) is an industry standard Developed that defines the cables, connectors and communications protocols used in a bus for connection, communication and power supply between computers and electronic devices.

Versions of USB

• USB 1.0• USB 2.0• USB 3.0

Components of USB system• USB host controller• USB hub• USB cable• USB peripheral devices

USB host controller

• It is an interface that allows an enabled piece of hardware to interact and communicate with a particular piece of software.

• USB host controller is a card that easily installs into any available slot in the motherboard. • The back-facing plate of the controller provides two or

more USB ports.

USB hubs

• A USB hub is a device that expands a single USB port into several so that there are more ports available to connect devices to a host system• A USB hub is a small, light unit with multiple ports for

plugging in USB devices.

PEHRIPHERAL DEVICES

• A peripheral is a device that is connected to a host computer , but not part of it.• It expands the host's capabilities but does not form part of

the core computer architecture.• Ex.- Mouse,keyboard,Printer

USB TOPOLOGY

• USB elements connected via a tiered star topology.• It supports up to 127 devices.

USB SYSTEM DESIGN

USB TRANSFER TYPES

• Isochronus transfer• Interrupt transfer• Bulk transfer

USB PACKETS

• USB data travels in packets• Identified by “Packet ID” (PID)• Token packet tells what’s coming• Data packets deliver bytes• Handshake packets report success or failure

Packet IDs(PIDS)

• TOKEN PACKETS

IN,OUT,SOF,SETUP• DATA PACKETS

DATA0,DATA1(USB LS/FS)

DATA2,MDATA (USB HS)• HANDSHAKE PACKETS

ACK,NAK,STALL (USB LS/FS)

NYET (USB HS)

USB DESCRIPTORS AND TYPES

• USB descriptors keep every information about the device.• Descriptors typically reside in non-volatile data storage on the

device.• Device descriptor• Configuration descriptor• Interface descriptor• Endpoint descriptor

Descriptor types

• Device descriptor• Configuration descriptor• Interface descriptor

Device descriptor

• USB devices can only have one device descriptor.

• The device descriptor includes information such as what USB revision the device complies to, the Product and Vendor IDs.

• The number of possible configurations the device can have.

Interface descriptor

• The interface descriptor could be seen as a header or grouping of the endpoints into a functional group performing a single feature of the device.

• There is no limitation as to having only one interface enabled at a time.

USB CONNECTORS

PIN CONFIGURATION OF USB CONNECTORS

Difference between RS232 and USB

USB

• In usb only 4 to 5 pins are there.• USB ports are compact in

size. • USB speed is now

increase upto 5 gbps.• USB supports plug and

play feature.

RS232

• RS232 has many pins and then it is again divided into male and female pins.• RS232 is bulky and cover

more space.• RS232 spped

aproximately is 10 Mbps.• RS232 USES UART

COMMAND

ADVANTAGES OF USB• Ease of use• One interface for many devices• Automatic configuration• No user settings• Speed• Reliability• Low cost• Low power consumption

WIRELESS USB

• Wireless USB will build on the success of wired USB, bringing USB technology into the wireless future.

• Wireless USB is a short-range, high-bandwidth wireless radio communication protocol created by the wireless USB promoter group.

• The basic transport mechanism for Wireless USB is the ultra-wide band (UWB) radio platform.

Topology of WUSB

FEATURES OF ULTRA WIDE BAND

• Speed/Range-Scaleable speeds up over 1 Gbps• Currently 480 Mbps at 3 m; 110 Mbps at 10 m• Frequency: 3.1 GHz to 10.6 GHz• Divided into 14 bands; 5 group• Each band is 528 MHz wide• OFDM symbols are interleaved across all bands• Provides protection against multi-path / interference

USB Flash drives

• A Flash Drive is a type of portable USB drive that stores and transfers data located on your computer working similar to floppies in that information can be stored and written on them.

• This device enables you to read , write , copy, delete and move data from USB flash drives to your hard disk drive and back again.

ADVANTAGES OF WIRELESS USB

• It is the easy and secure from plugging it in / unplugging it

• You do not need to have a network cable between the device and the network.

• You can connect fairly easily at home, work, multiple offices.

• You can move around or work at any available or suitable location without having to be near a socket.

DISADVANTAGE OF WIRELESS USB• Unless the security is not properly setup, both your laptop

or desktop and the network you are connecting to cannot be compromised and your data can be accessed by others.

• The hardware is small, it can get damaged, lost or stolen.

• Some older wireless networks can get very slow if there are lots of people in the same area, all trying to use the network (

APPLICATIONS OF WIRELESS USB

• Game consoles• Digital cameras• Digital camcorders• DVD players• Printers• Scanners• Projectors

USAGE APPLICATIONS OF WIRELESS AND WIRED USB

USAGE APPLICATIONS OF WIRELESS AND WIRED USB