
EZ-USB FX2 Technical Reference Manual
Page 1-2 EZ-USB FX2 Technical Reference Manual v2.1
matically loads the device’s driver into the operating system. When the device is
unplugged, the operating system automatically logs it off and unloads its driver.
• USB devices do not use DIP switches, jumpers, or configuration programs. There is never
an IRQ, DMA, memory, or I/O conflict with a USB device.
• USB expansion hubs make the bus simultaneously available to dozens of devices.
• USB is fast enough for printers, hard disk drives, CD-quality audio, and scanners.
• With the introduction of the USB 2.0 Specification, USB supports three speeds:
-
Low Speed
(1.5 Mbits/sec), suitable for mice, keyboards and joysticks.
-
Full Speed
(12 Mbits/sec), for devices like modems, speakers and scanners.
-
High Speed
(480 Mbits/sec), for devices like hard disk drives, CD-ROMs, video cam-
eras, and high-resolution scanners.
The Cypress Semiconductor EZ-USB FX2 augments the EZ-USB family by supporting the high
bandwidth offered by the USB 2.0 High Speed mode. The FX2 provides a highly-integrated solu-
tion for a USB peripheral device. Like all EZ-USB devices, the FX2 offers the following features:
• An integrated, high-performance CPU based on the industry-standard 8051 processor.
•A
soft
(RAM-based) architecture that allows unlimited configuration and upgrades.
• Full USB throughput. USB devices that use EZ-USB chips are not limited by number of
endpoints, buffer sizes, or transfer speeds.
• Automatic handling of most of the USB protocol, which simplifies code and accelerates
the USB learning curve.
1.3 The USB Specification
The
Universal Serial Bus Specification Version 2.0
is available on the Internet from the USB Imple-
menters Forum, Inc., at http://www.usb.org. Published in April, 2000, the USB Specification is
the work of a founding committee of seven industry heavyweights: Compaq, Hewlett-Packard,
Lucent, Philips, Intel, Microsoft, and NEC. This impressive list of developers secures USB’s posi-
tion as the low- to high-speed PC connection method of the future.
A glance at the USB Specification makes it immediately apparent that USB is not nearly as simple
as the older serial or parallel ports. The USB Specification uses new terms like endpoint, isochro-
nous
, and
enumeration
, and finds new uses for old terms like
configuration
,
interface
, and
inter-
rupt. Woven into the USB fabric is a software abstraction model that deals with things such as
pipes. The USB Specification also contains information about such details as connector types and
wire colors.
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