The ISP1562 is a Peripheral Component Interconnect (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 two transceivers that are compliant with Hi-Speed USB and Original USB. The functional parts of the ISP1562 are fully compliant with Universal Serial Bus Specification Rev. 2.0, Open Host Controller Interface Specification for USB Rev. 1.0a, Enhanced Host Controller Interface Specification for Universal Serial Bus Rev. 1.0, PCI Local Bus Specification Rev. 2.2, and PCI Bus Power Management Interface Specification Rev. 1.1. The integrated high performance USB transceivers allow the ISP1562 to handle all Hi-Speed USB transfer speed modes: high-speed (480 Mbit/s), full-speed (12 Mbit/s) and low-speed (1.5 Mbit/s). The ISP1562 provides two downstream ports, allowing simultaneous connection of USB devices at different speeds. The ISP1562 is fully compatible with various operating system drivers, such as Microsoft Windows standard OHCI and EHCI drivers that are present in Windows XP, Windows 2000 and Red Hat Linux. The ISP1562 directly interfaces to any 32-bit, 33 MHz PCI bus. Its PCI pins can source 3.3 V. The PCI interface fully complies with PCI Local Bus Specification Rev. 2.2. The ISP1562 is ideally suited for use in Hi-Speed USB mobile applications and embedded solutions. The ISP1562 uses a 12 MHz crystal.