Standardized plug and port!
USB makes adding peripheral devices so easy, anyone can do
First, USB replaces all the different kinds of serial and
parallel port connectors with one standardized plug and port
combination. It looks like this:
With USB-compliant PCs and peripherals, you just plug them in
and turn them on! USB makes the whole process automatic. It's
like adding instant new capabilities to your PC. You never need
to open your PC, and you don't need to worry about add-in cards,
DIP switch settings or IRQs.
The USB On-The-Go (OTG) specification has added Mini-A
plugs and receptacles to the original USB A and B connectors,
along with a "Mini-AB" receptacle,
to support smaller portable devices such as cameras and PDA's.
These plugs and receptacles are
considerably smaller than their original
full-size counterparts (Fig.
Just plug it in and go!
Thanks to another USB feature known as
"hot-swapping" you don't even need to shut down and
restart your PC to attach or remove a peripheral. Just plug it
in and go! The PC automatically detects the peripheral and
configures the necessary software. This feature is especially
useful for users of multi-player games, as well as business and
notebook PC users who want to share peripherals.
USB also lets you connect many peripherals at one time. Many
USB PCs come with two USB ports. And special USB peripherals --
called USB hubs -- have additional ports that let you "daisychain"
multiple peripherals (devices) together.
Another cool USB feature is that it distributes electrical
power to many peripherals. Again, USB lets the PC automatically
sense the power that's required and deliver it to the device.
This interesting USB feature eliminates those clunky power
USB connections allow data to flow both ways between the PC
and peripheral. This means you can use your PC to control
peripherals in new and creative ways.
For example, you can use your PC to automatically manage a
telephone call center to maintain voice, fax and data mailboxes,
screen and forward your calls, and even deliver a variety of
selected outgoing messages.
Or you can use your PC to tune a set of USB-compliant stereo
speakers to match the acoustics of your listening environment.
(Keep It a Simple System)
IN THE LINE OF
Allyn Pon, Cypress
Director of Product Marketing, Interface Products Division
Cypress Semiconductor, San Diego, CA
what PC users want, and if the industry is to grow, PC,
peripheral, and IC manufacturers will have to provide it. In
response, the PC industry developed USB, an interconnect
technology featuring smaller connectors, easier installation,
port expandability, and faster performance than legacy ports. In
other words, USB is simpler and better—the reason why it will
ultimately prevail over other standards.
that transitions to new technology work best if they provide
significant user benefits, standards compatibility, industry
support, transparency, and cost effectiveness. Let's see how USB
2.0 stacks up in these areas.
Benefit. USB 2.0 is fast. Most PC peripherals need
bandwidth somewhere between 6Mbit/sec. and 75Mbit/sec., so USB
2.0's 480Mbit/sec. provides full bandwidth for everyone. Even
one of the most demanding applications, uncompressed video, only
Despite the 40-times increase in bandwidth, USB 2.0 is still
a simple "user obvious" technology. Small connectors,
easy installation via plug-and-play, and only one cable type all
contribute to the new standard's simplicity and ease of use.
Only one connector style is needed for the entire PC system, the
simplest system of any of the competitors.
USB 2.0 is fully backward- and forward-compatible with USB 1.1.
Existing USB 1.1 peripherals will continue to work for PCs
equipped with USB 2.0. Looking at it the other way around, most,
if not all, USB 2.0 peripherals plugged into a USB 1.1-based PC
will operate under USB 1.1 operating conditions. In either case,
the system continues working flawlessly, and runs at the fastest
Today, just one year after the formation of the USB 2.0
Promoters Group, there are 19 silicon suppliers (and more
coming) who have pledged solutions for this standard, including
Cypress Semiconductor. USB 2.0 was demonstrated at the Intel
Developer Forum last February. The final specification was
recently released, on schedule. This type of momentum is
unprecedented in the PC industry. With the task of learning USB
1.1 behind it, Microsoft is moving quicker than ever to
incorporate USB 2.0 into current and future operating systems.
There will always be a class of novice users who will benefit
from having new technology work without their needing to know
that it even exists. USB 2.0 uses the same cables as USB 1.1.
The connector shapes are the same. The topology is the same. So
if the user doesn't know the difference between USB 1.1 and USB
2.0, the system will still work.
effectiveness. Cost is very difficult to compare,
because a number of variables can influence the final cost of
the product. Another I/O standard, 1394 (FireWire), achieves
similar speeds to USB 2.0 and thus is a good model for
comparison. The most widely accepted comparison standard is the
use of gate counts to provide an apples-to-apples comparison.
Vendors who supply USB 2.0 and 1394 solutions estimate that 1394
host controllers have two to three times more gates than do USB
2.0 controllers. Vendors also estimate that 1394 peripheral
controllers have four to five times more gates than comparable
USB 2.0 peripheral silicon. With Intel planning to integrate USB
2.0 host controllers into future chipsets, the system costs of
implementing USB 2.0 will be incremental vs. the cost of adding
a discrete host controller for something like 1394.
No other technology
meets all of these criteria, which is why the USB 2.0 train is
moving so fast.