The ISP1561 is a PCI-based, single-chip Universal Serial Bus (USB) Host Controller. It integrates two Original USB Open Host Controller Interface (OHCI) cores, one Hi-Speed USB Enhanced Host Controller Interface (EHCI) core and four transceivers that are compliant with Hi-Speed USB and Original USB. The functional parts of the ISP1561 are fully compliant with Universal Serial Bus Specification Rev. 2.0, Open Host Controller Interface Specifications Rev. 1.0a, Enhanced Host Controller Interface Specification for Universal Serial Bus Rev. 0.95, PCI Local Bus Specification Rev. 2.2 and PCI Bus Power Management Interface Specification Rev. 1.1.