USS-344

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 environment 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. Fullspeed or low-speed peripherals are supported along with all of the USB transfer types: control, interrupt, bulk, or isochronous. The USS-344's OpenHCI compliance offers significant USB performance benefits and reduced CPU overhead compared to other USB UHCI host controllers.

In addition, the USS-344 offers a significant performance 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 m 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.