| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a controller for reducing power consumption in equipment such as a PC to which a USB device is connected, and a transfer speed control method. <P>SOLUTION: A USB3 host controller 1 includes: a transfer data conversion part 12 for mutually converting between transfer data from a USB device 3 and transfer data from a PCI Express bus; and a transfer speed switching part 15. The transfer speed switching part 15 is configured to, when the USB device 3 is connected, receive transfer information relating to the data transfer from the USB device 3 via a USB3 interface 13, and to find a transfer speed to be used at a PC side on the basis of the transfer information or the analytical result of the transfer information, and to, when the current transfer speed at the PC side is different from the found transfer speed, transmit a speed switching signal D3 for instructing the switching of the current transfer speed to the found transfer speed, to a PCI master 2 via a PCI Express interface 11. <P>COPYRIGHT: (C)2013,JPO&INPIT |
