| Tech Tips-USB2
for the Reporting to the MAX Larry Sweat
Information Systems and Design Manager
What is USB and how will it affect us?
Universal Serial Bus (USB) is a primary component of the Easy PC Initiative, an
industry initiative led by Intel and Microsoft to make PC’s easier to use. USB 1.0
was developed in 1995 and first introduced by Intel. It is a new method of connecting
peripheral components to PC’s that eliminates the clutter and confusion of the
numerous and various connectors found on the back of the typical PC.
USB versions of all peripheral devices that connect to a PC are currently
available or in development. The list of USB devices available for PCs includes keyboards,
mice, joysticks, printers, scanners, fax/modems, digital cameras, portable storage
devices, network adapters, digitizer tablets, light pens, and plotters. All new PC
motherboards being manufactured today include one or more USB ports meeting the USB 1.1
standards. USB 2.0 is scheduled for introduction this year. USB 2.0 will provide a higher
performance interface and a wider range of peripherals available including high-speed
multi-media video and audio.
A USB system configuration consists of three components. The USB HOST is the PC
hardware and operating system. The HOST detects and identifies the peripherals attached to
the system and loads the appropriate device driver for each peripheral. It assigns each
peripheral a unique address and directs traffic to and from the peripheral. USB devices
can be connected and disconnected while the HOST is running and the HOST will detect and
respond to each device immediately without rebooting the computer. The HOST hides all of
the details of the hardware configuration from software applications (including Cougar
Mountain applications) eliminating the need (and the ability) to control the hardware.
The USB HUB connects to the HOST and provides the ability to connect up to 270
peripheral devices to the system. It also provides up to 2.5W of power to each peripheral,
eliminating the need for an additional power source for most peripherals. Peripherals with
higher voltage requirements will still need an additional power source.
The USB PERIPHERAL is a slave device that communicates with the HOST using a
defined protocol. The Peripheral must respond to requests from the HOST and react to
control instructions from the HOST.
The peripheral sends and receives data to and from the HOST using a standard USB
data format. The standardized data movement gives USB tremendous flexibility with minimal
involvement of the software applications. |
