Patent ID: 7904625

Claim:
An apparatus comprising: a Universal Serial Bus (USB) transceiver of a USB host controller, wherein the USB transceiver has a differential output; a first pull-down resistor; a first switch to electrically couple the first pull-down resistor to a positive terminal of the differential output in response to a first switch control signal; a second pull-down resistor; a second switch to electrically couple the second pull-down resistor to a negative terminal of the differential output in response to a second switch control signal; and a detachment module to selectively determine whether a USB device is electrically coupled to the differential output by checking a voltage at the differential output while at least one of the first switch control signal or the second switch control signal is asserted, wherein the detachment module determines whether the USB device is electrically coupled to the differential output by checking the positive terminal when the USB transceiver is in a full-speed idle state, and checking the negative terminal when the USB transceiver is in a low-speed idle state.