Patent ID: 7320077
Filing Date: 2008-01-15
Classification: G06F

Abstract:
1. A power supply controlling apparatus embedded in a hub device capable of communicating data with a connected host and coupled devices, comprising: a data detector configured to output a power control signal in response to states of signals carried by data lines correspondingly coupled between the hub device and bus-powered coupled devices; a power supply device in the hub device configured to supply power to the bus-powered coupled devices; and a controller in the hub device configured to selectively shut off power supply from the hub device for the bus-powered coupled devices based on the outputted power control signal, wherein the controller is configured to stop power supply from said power supply device for one bus-powered coupled device responsive to the power control signal when the states of the signals represent an inoperative state of said one bus-powered coupled device, and wherein the controller is configured to maintain the power supply from said power supply device responsive to said power control signal for at least one other bus-powered coupled device, wherein the data detector conducts a logical operation on the signals of the data lines, and monitors a time interval for a result of the logical operation maintained at a prescribed one of a plurality of levels, and outputs the power control signal based on the monitored time interval.