eXtensible Host Controller Interface (xHCI)

eXtensible Host Controller Interface (xHCI) is a computer interface specification that defines a register-level description of a host controller for Universal Serial Bus (USB), which is capable of interfacing with USB 1.x, 2.0, and 3.x compatible devices. The specification is also referred to as the USB 3.0 host controller specification. eXtensible Host Controller Interface (xHCI) is a computer interface specification that defines a register-level description of a host controller for Universal Serial Bus (USB), which is capable of interfacing with USB 1.x, 2.0, and 3.x compatible devices. The specification is also referred to as the USB 3.0 host controller specification. The xHCI is a radical break from the previous generations of USB host controller interface architectures (i.e. the Open Host Controller Interface (OHCI), the Universal Host Controller Interface (UHCI), and the Enhanced Host Controller Interface (EHCI)) on many counts.Following are the key goals of the xHCI architecture: