History • The USB 1.0 model was introduced in November 1995 as the first form of USB. • USB was created by the main group of core companies that consisted of Intel, Compaq, Microsoft, Digital, IBM, and Northern Telecom. • Each company contributed to the creation of USB in one way or another. • The original Apple iMac G3, introduced May 6, 1998, was the first computer to offer USB ports without offering “legacy ports”. • 13 years later, 2008 the USB 2.0 was finally introduced.
USB has the capability of transferring 12 Mbps. Supporting up to 127 devices and only utilizing one IRQ. Devices can be up to 30 meters away from the host. Lets you attach anything from mice to keyboards to your computer. The operating system supports USB. USB is by far the easiest way to connect any device to your computer. USB(universal serial bus)
Features... • USB devices are hot-swappable, meaning you can plug them into the bus and unplug them at any time. • A USB cable has two wires for power(+5 volts and ground) and a twisted pair of wires to carry the data. • The computer can supply up to 500 milliamps of power at 5 volts.
Features • With USB 2., the bus has a maximum data rate of 480 megabits per second. • Low-power devices can draw their power directly from the bus. • High-power devices have their own power supplies and draw minimal power from the bus. • Hubs can have their own power supplies to provide power to devices connected to the hub. • The computer acts as the host.
The USB Process • When the host powers up, it queries all of the devices connected to the bus and assigns each one an address. This process is called enumeration- devices are also enumerated when they are connected to the bus. The host also finds out from each device what type of data transfer it wishes to perform. • There are 3 different types of data transfers…
Data Transfers • Interrupt- A device which will be sending very little data like a mouse or keyboard, would choose the interrupt mode. • Bulk- A device which receives data in one big packet, like a printer, uses the bulk transfer mode. A block of data is sent to the printer and verified to make sure it is correct. • Isochronous- A streaming device, such as speakers, uses the isochronous mode. Data streams between the device and the host in real-time, and there is no error correction. The host can also send commands or query parameters with control packets.
Cameras CD-Rom Drives Converters Joysticks Keyboards Printers Microphone Modem Monitors Mouse Mp3 players Network Removable Media Scanners Speakers TV Tuners Products that receive power through USB port
Purpose • In the past connecting devices to computers has been a real hassle and that is what USB is trying to resolve. • Devices that needed faster connections came with their own cards, which had to fit in a card slot inside the computer's case. The number of card slots is limited and you needed a Ph.D. to install the software for some of the cards. • The goal of USB is to solve all these problems. The USB gives you one standardized way to connect 127 devices to a computer
USB Connectors • There are several types of USB connectors. • The original USB plugs and receptacles were Standard-A and Standard-B. • Standard-A is most frequently seen on cables that are permanently attached to a device. • Standard-B is mainly used for the device end of a removable cable. • The Micro-USB connector is used to replace the Mini-USB plugs. • Microsoft’s Xbox game console used USB 1.1 signaling in its controllers and memory cards, but features proprietary connectors and ports. • There are at least 10 different types of non-standard Mini-USB receptacles and jacks currently in use. • USB-IF created the Micro series of receptacles and jacks, to focus on one jack that delivers both power and data.
Power • The USB provides a 5V supply on a single wire from which connected USB devices may draw power. • If a bus-powered hub is used, the other devices may only use a total of four units 400 mA of current. • This limits compliant bus-powered hubs to 4 ports. • The host operating system usually keeps track of the power requirements of the USB network and could issue a warning when a certain segment requires more power than what is there. • On-the-Go and Battery Charging Specification both add new powering modes to USB. • The main charger shorts the D+ and D- pins together and will not send or receive any information on those lines, which allows the creation of simple, high current chargers to be created. • The increased current will occur once the host/hub and devices both support the new charging specification. • As of June 14, 2007, all new mobile phones applying for a license in China are required to use a USB port as a power port. • Many mobile companies are announcing that its members had agreed on micro-USB as the future common connector for mobile devices.
Powered USB • Uses standard USB signaling with the addition of extra power lines. • It uses 4-additional pins to supply to supply power to other devices. • The wires and contacts on the USB portion have been upgraded to support higher current. • This is commonly used in retail systems and provides enough power to operate stationary barcode scanners, printers, pin pads, etc. • This standard was developed by IBM. • It is basically two connectors stacked so that the bottom connector accepts a standard USB plug and the top connector takes a power connector.
FireWire • FireWire is a method of transforming information between digital devices. • It is very fast, the latest version achieves speeds up to 800 Mbps and is expected to jump to an unbelievable 3.2 Gbps. • You can connect up to 63 devices with a FireWire bus. • Supported by both windows operating systems and Mac OS. • FireWire is plug-and-play, so when you connect a new firewire device to your computer, the computer auto-detects it and asks what you wish to do with it. • FireWire devices are hot-pluggable, which means they can be connected and disconnected at any time, even with the power on.
Specifications • The original FireWire was faster than USB when it came out. • Transfer rates of up to 400 Mbps. • The maximum distance between devices is 4.5 meters of cable length. • Eventually, FireWire 800 replaced USB 2.0 very easily. • FireWire 800 had a transfer rate of up to 800 Mbps. • The maximum distance of cable length between devices is 100 meters.
IIDC(Instrumentation & Industrial Digital Camera) • This is the FireWire data format standard for live video. • This system was designed for machine vision systems. • Also used for some computer application programs. • This is often confused with another system because they both used FireWire; DV(Digital Video)
Future Enhancements • Besides the short term life span of S3200 over the beta connector, future creations of FireWire should bring an increase in speed to 6.4 Gbit/s, use of single-mode fiber, and additional connectors such as the smaller port.
USB/FireWire Manufacturers • Dell-examples: IEEE 1394a FireWire Controller card for Dell Workstations, OptiPlex GX280 Desktop, Dual PCI riser for Dell OptiPlex 745 Desktop System. • ADC-examples: Campus-RS FLEX expansion module & CAFLEX Multi-Port Campus-RS expansion module. • Logitech • Kensington • Belkin Components • ADS Technologies • American Power Conversation
Sources • http://accessories.us.dell.com/sna/category.aspx?c=us&category_id=6175&cs=04&l=en&s=bsd&~ck=anav&ST=usb%20hubs&dgc=ST&cid=33011&lid=774566 • http://en.wikipedia.org/wiki/USB#Types_of_USB_connector • http://en.wikipedia.org/wiki/FireWire http://en.wikipedia.org/wiki/USB