Universal Serial Bus (USB)

Cory KobyFred Smith Jr.

Table of Contents USB 1.0 / 1.1 USB 2.0 USB 3.0 Comparison and Compatibility

Time Lines of USB and FireWire

FireWire 400 800 s3200

1995 2001 2010 1.0/1.1 2.0 3.0

USB

USB 1.0 and 1.1 USB is a high performance universal serial bus

communication technology used on computers and peripherals to transfer data between them.

USB has four types of communication transfer modes Control - is initiated by the host. Control mode is

used in initialization of devices, but it can transfer small amounts of data.

Interrupt - is used by the host to query a device to check if it needs to be serviced.

Bulk - an example of Bulk is disk drivers. Isochronous - an example of Isochronous is USB

audio speakers.

USB 1.0 and 1.1 continued USB

Developed due to problems and complications caused by having so many connections for peripheral devices on computer systems.

Too many different types of ports with limited uses Serial, Parallel, PS/2, Etc

USB solved this limitation by limiting the number of different types of ports needed to connect to a computer. USB is specifically designed to allow easy connection of a wide variety of devices. It is intended to be user friendly.

USB 1.0 and 1.1 Benefits Technology allows for up to 127 Device to

be connected at a time to a host controller.

Allows for Hot-Swapping Your device can be plugged and unplugged

safely whenever you like. Allows for “Plug and Play” of devices

Operating system automatically recognizes the USB device and loads the appropriate drivers.

USB 2.0 USB 2.0 is the upgrade

to the 1.1 Standard Technology was

introduced and standardized in 2001 Upgrades were

continued to be made to the Standard through ECN’s ECN (Engineering

Change Notice)

Benefits of USB 2.0 Increased Speed over 1.0/1.1

USB 1.0/1.1 Max Speed was 12Mbits/s USB 2.0 Max Speed is 480 Mbit/s

40x Faster than 1.1 Was given the title Hi-Speed

Simplifies connectivity to System BUS Decreases number of connectors needed

Is Backwards compatible with USB 1.0 and 1.1 Devices

Current Trends USB 2.0 is mainly used for expandability

External Hard Disks, External CD/DVD-ROMs, External CD/DVD-Burners These devices, with USB 1.0/1.1, could only

operate at a fraction of their capacity, but USB 2.0 and its 480 Mbit/s bandwidth allows for much faster data transfer and communication.

Ports are currently used on a multitude of portable devices to transfer information Cell Phones, MP3 Players, Digital Cameras,

etc.

USB 3.0: Superspeed Certified under the name ‘SuperSpeed’

New Theoretical Max = 5 Gbits/s Upgraded from Half-Duplex (1.0/1.1/2.0)

to Full-Duplex communication with Peripherals No longer uses Polling, technology

upgraded to packet-routing. Lower Power Consumption

Reduced by 85%

Competitors/Comparison

Competitors Firewire S3200

Firewire runs at 3.2 Gbits/s

Full duplex communication (bi-directional)

eSATA Used for External Hard

Drives Runs at 3.2 Gbits/s

USB 3.0 Speed – 4.8 (Actual)

5 Gbits/s (Theoretical) Full-Duplex

Bi-Directional Communication with Peripherals

Packet Routing Allows for power saving and

faster data transfer. All devices can transfer at

the same time

Backwards Compatible USB 3 and 2.0 are backwards

compatible, though the speed is automatically scaled down to the lower technology.

USB cables are all the same format for connectors. However, for extra power, USB 3.0 cables

are specially hard-wired for printers and scanners, etc.

New connectors for USB 3.0 are blue.

References Unknown. "Universal Serial Bus (USB *) Specifications.“

Intel.com. Intel, N.D. Web. 21 Jan 2013. http://www.intel.com/technology/usb/spec.htm?iid=Tech_usb+spec2.

Allyn-Feuer, Ari. “Super speed: a brief history of USB 3.0, 2007-2018.” ARSTechnica, Web. 1 Feb 2013. http://arstechnica.com/gadgets/2009/08/super-speed-a-brief-history-of-usb-30/2/.

Viswanath, Somnath. “SuperSpeed USB 3.0: Ubiquitous Interconnect for Next Generation Consumer Applications” Arasan Chip Systems Inc., Web. 2 Feb 2013. http://arasan.com/wp-content/media/Arasan_USB_3_0_Enables_New_Usage.pdf.

White Paper. “USB 3.0* Radio Frequency Interference Impact on 2.4 GHz Wireless Devices” Intel, N.D. Web. 1 Feb 2013. http://www.usb.org/developers/whitepapers/327216.pdf

Universal Serial Bus (USB)

Cory KobyFred Smith Jr.