The Universal Serial Bus
Making User Interface Faster and Easier
Imagine adding as many peripheral devices as you wantto a PC—all with one common connector—without
regard to placement. Imagine plugging-in full-motion
video to your host. Imagine swapping peripheral devices
at will without having to reboot the system.These are the major benefits of the Universal Serial Bus.
The Universal Serial Bus, or USB, is a PC industry standardof simplifying the user
interface of peripheral devices to
a host PC. Today, peripherals are connected to one of
many ports on the back of a PC. Keyboards are connected
to keyboard ports,
mice to
mouse ports, monitors and
printers to serial or parallel ports, speakers and microphones
to separate jacks, and so on. This is confusing to users
because of the wiring and cabling complexity. USB
replaces all of these types of connections with one,
universal port style. This means that the same type ofconnection can be used for all peripheral devices, includ-ing the
mouse, monitor, keyboard, speakers, etc.In addition, a USB expands a system’s capability by allowingthe host to communicate with multiple peripherals. In
the old days, if a user wanted to have two different
serial devices or two different parallel devices hooked
to his PC, he had to have an A/B switch box that allowed
him to manually change devices. This was very cumbersome.
The USB supports multiple peripherals tied to a hub. No
manual switching is required.Identifying and assigning an address to peripherals isaccomplished through a process called enumeration.
Enumeration identifies each device and assigns it a
unique address for communication with the host. The Universal Serial Bus, or USB,is a PC industry standard wayof simplifying user
interface ofperipheral devices to a host PC.
