Patent ID: 8572420

Claim:
An apparatus, comprising: a computer system, comprising: a central processing unit (CPU); a computer controller coupled with the central processing unit, wherein the computer controller comprises a USB host controller and a separate controller for handling said sideband signal; wherein the computer controller is configured to communicate with a Universal Serial Bus (USB) device coupled to the computer system via a first medium and a second medium, wherein the USB device is external to the computer system, wherein the computer system and USB device are coupled to perform USB communications using the first medium and to perform sideband communications using the second medium, wherein the first medium and the second medium are different; wherein the computer system is configured to communicate the sideband signal to the USB device over a sideband signal line when the sideband signal line is coupled to the computer system; and wherein the computer system and USB device are operable to use the sideband signal line to trigger the other of the computer system or USB device to return to a normal power state from a low power state and wherein during the low power state the separate controller buffers data received from the USB device until the computer system returned to the normal power state.