| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve such a problem that a communication speed between a HUB device having a plurality of connection ports and a USB device temporarily drops due to enumeration processing caused when another USB device is connected to the other connection port of the HUB device while the HUB device and the USB device are intercommunicating data. <P>SOLUTION: A control device 104 verifies connection states of USB devices to connection ports 102 to 102d, and when data communication request occurs between a HUB device 101 and a USB device 120, stops power supply to the connection ports 102b to 102d to which the USB device 120 is not connected. Then, after data communication is completed, the control device 104 restarts power supply to the connection ports 102b to 102d. Thus, enumeration processing is not executed even if another device 121 is connected to one of the connection ports 102b to 102d during data communication, so that it is possible to prevent reduction of a communication speed between the HUB device 101 and the USB device 120. <P>COPYRIGHT: (C)2013,JPO&INPIT |
