| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To perform optimal suspend processing on a USB device side, without depending on a USB host device, to realize satisfactory reduction in power consumption. <P>SOLUTION: When communication is made between a USB host device 1 and a USB device 2 by connecting a USB cable 3, the monitoring part 9 of a transceiver part 5 on the USB device 2 side monitors packets. When the monitoring part detects a state in which there is no effective packets for a prescribed period of time and only SOF packets are received, after that, it stops the transmission of data to a USB controller part 6. By this, the USB controller part 6 determines that activity on a bus is lost and makes control for a transition to a suspended state to reduce power consumption. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
