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.