Advance Data Sheet, Rev. 9
June 2001
USS-344
QuadraBus™
Four-Host PCI-to-USB OpenHCI Host Controller
Features
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Description
The Agere Systems Inc. USS-344
QuadraBus
provides
a single-chip four-host PCI-to-Universal Serial Bus
(USB) solution. The USS-344 interfaces directly to any
32-bit, 33 MHz PCI bus and is ideal for either onboard
applications or add-in card applications. It can easily be
configured to communicate in either a 3 V PCI environ-
ment or 5 V PCI environment simply by selecting the
appropriate communications voltage level on the VIO
input pin.
The USS-344 provides four downstream USB ports for
connectivity with any USB compliant device or hub. Full-
speed or low-speed peripherals are supported along
with all of the USB transfer types: control, interrupt,
bulk, or isochronous. The USS-344’s OpenHCI compli-
ance offers significant USB performance benefits and
reduced CPU overhead compared to other USB UHCI
host controllers.
In addition, the USS-344 offers a significant perfor-
mance advantage over all other USB host controllers
(both UHCI and OHCI) by providing full USB bandwidth
to each port rather than sharing the USB bandwidth
over all ports. This results in an increase in the number
of devices which can feasibly be connected to a
computer system as well as ensuring high-bandwidth
devices, such as video cameras and audio devices, are
always provided with the high bandwidth they need
while other USB devices are in use.
The USS-344 is a multifunction PCI device with one
single-port USB host controller per PCI function. There
are four PCI functions in the USS-344 for a total of four
single-port USB host controllers. Each single-port host
controller provides the full USB bandwidth (12 Mbits/s)
for devices connected downstream of its port.
The USS-344 is fully compatible with the
Microsoft
Windows
standard OpenHCI drivers. The USS-344
pinout is compatible with the future release of the Agere
USB 2.0 host controller.The USS-344 is a 3.3 V device
fabricated in 0.25
µm
technology. Integrated dual-speed
USB transceivers enable a single-chip PCI-to-USB
solution. The USS-344 provides full support for legacy
PC peripherals as defined in the
OpenHCI Open Host
Controller Interface Specification for USB Release 1.0a.
*
Microsoft, Windows,
and
Windows NT
are registered trademarks
of Microsoft Corporation.
†
Mac
is a registered trademark of Apple Computer, Inc.
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32-bit, 33 MHz PCI interface compliant with
PCI Local
Bus Specification Revision 2.2
Four downstream USB ports
Each USB port dedicated to providing full USB band-
width to the attached device
Full compliance with
Universal Serial Bus Specifica-
tion Revision 1.1
OpenHCI Open Host Controller Interface Specifica-
tion for USB Release 1.0a
compatible
Fully compatible with
Microsoft Windows
98/95/Win-
dows NT
* standard OpenHCI drivers
Fully compatible with
Mac
†
OS 8.5 and 8.6
Integrated dual-speed USB transceivers
3 V or 5 V switchable PCI signaling
Low-power mode and wake-up compatible with
PCI
Power Management Interface Specification Revision
1.1
Supports up to 127 devices per port
Supports peripheral hot swap and wake-up
Support for legacy keyboard and mouse
128-pin TQFP package
Full 12 Mbits/s bandwidth per port
Evaluation kit:
— PCI card
— Data sheet
0.25
µm
technology
Applications
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Seamless integration with 3 V or 5 V PCI-based com-
puter products
Supports all USB compliant devices and hubs
Simultaneous operation of multiple high-performance
devices
AGERE [ AGERE SYSTEMS ]
