USB 3.0 host controller driver (Usbxhci.sys) The KMDF driver model reduces complexity and improves stability. Microsoft created the USB 3.0 drivers by using Kernel Mode Driver Framework (KMDF) interfaces. The USB 2.0 driver stack ships in Windows XP with Service Pack 1 (SP1) and later versions of the Windows operating system. Windows loads the USB 2.0 driver stack for devices that are attached to eHCI, oHCI, or uHCI controllers. Windows loads the USB 3.0 driver stack when a device is attached to an xHCI controller.
The diagram shows separate USB driver stacks for USB 2.0 and USB 3.0. The following figure shows the architectural block diagram of the USB driver stack for Windows. This article provides an overview of the Universal Serial Bus (USB) driver stack architecture.
