USB 2.0 (Universal Serial Bus)

USB 2.0 (Universal Serial Bus) is a communication bus that enables up to 127 peripherals to be linked to a personal computer. Peripherals as varied as a mouse, keyboard, camera, CD writer, telephone or handheld assistant can share the bandwidth of a single bus.

Background

USB was designed to simplify the user's life. Meaning that the latter can connect and disconnect peripherals "hot" (Hot Plug and Play) and doesn't need to worry about configuring hidden addresses or other DMA channels.

The use of standard classes allows any software, which supports a specific class, to use any peripheral which operates on that class, even if this was non-existent when the software was developed. Here are some examples of these classes:

• Human Interface Devices: keyboard, mouse, joystick, buttons, etc.
• Audio: speaker, microphone, mixer, etc.
• Mass storage: disk drive, hard disk, CD or DVD reader, etc.
• And others such as communication, printers, etc.

USB adds a new dimension to modern IT, reducing the technical operations performed by the user to a strict minimum, making him much happier!

New challenges for developers

But this simplicity comes at a price: complexity is transferred from the peripheral user to the developer. This means that the work of the latter is increased and that he needs the appropriate tools.

A powerful protocol analyzer is vital for the success of USB projects. It enables transmitted data to be checked, performance to be analyzed and developers to be directed to official documents, should he entertain any doubts. Ellisys proposes a product line that covers the most demanding USB analysis needs.

Find out more about Ellisys USB analyzers  »

Future of the technology

Wireless USB
To further ease the life of users, the USB-IF created a new wireless extension of USB called Wireless USB. Ellisys released an article demystifying this new protocol by comparing it to wired USB. This article helps USB developers willing to jump to this new cutting edge technology by explaining its basic concepts.

To help developers in this new challenge, Ellisys developed a complete portfolio of development tools for Wireless USB.

SuperSpeed USB
The future of the USB technology is here. SuperSpeed USB pushes the speed of USB communication to the multi-gigabit world, competing with the fastest technologies available today on the market. Ellisys designed the industry's first protocol test equipment to help adopters of this technology.

Links

Here are a few links to pages containing a whole information range about USB.

USB homepage
USB general FAQ
USB developers FAQ
USB specification and related documents
USB developers webboard
USB DevCon presentations

USB Complete (Jan Axelson)
USB Design By Example (John Hyde)
Programming the WDM (Walter Oney)
USB in a NutShell (Craig Peacock)
USB device drivers, slave and host stacks (Jungo)
USB device and driver development (Andrew Pargeter)

Challenges of Migrating to Wireless USB (article)
Linux USB homepage
Intel USB homepage
Microsoft USB homepage
Academy of USB (test your knowledge of USB)