| 摘要 |
<p>A system for implementing a virtual Universal Serial Bus (USB) compound device with a simulated hub enables a single physical USB device, such as a USB peripheral device, to expose multiple stand-alone functions on the USB bus. Logical functions on the single physical USB device can be added and removed dynamically without re-enumerating the entire device and without affecting the state of other functions. Logical functions can also be independently implemented on any of a number of processors in a system that has access to the USB hardware. Each processor can enumerate as one or more USB devices via the virtual hub. Initialization of logical functions can be performed via the virtual USB hub to maintain a charging current level from a USB host in a device having a discharged battery.</p> |
