| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress current consumption by reducing a transfer throughput of packet data communication when a residual battery amount in a USB host system becomes small. <P>SOLUTION: The USB host system includes: a USB host device (12) operated by a battery as a power source and executable of USB communication between with a USB peripheral device (12); and a residual battery amount monitoring circuit (113) for monitoring the residual amount of the battery. The USB host device includes a throughput adjustment unit (114) for adjusting each packet output interval to the USB peripheral device, on the basis of the monitoring result by the residual battery amount monitoring circuit. The throughput adjustment unit determines the packet output interval to the USB peripheral device, using a start-of-frame interruption formed at a predetermined time interval. When the residual battery amount becomes small, the packet output interval is adjusted to suppress current consumption. <P>COPYRIGHT: (C)2013,JPO&INPIT |
