| 摘要 |
PROBLEM TO BE SOLVED: To enable the device connection propriety determination considering the state of a USB device connected to a USB port of a USB host, when the USB host is switched from normal operation mode to power-saving mode.SOLUTION: When a new USB device is connected to a USB port 103-1 or 103-2, a USB host 10 measures and stores actual use current values of the USB device in normal operation mode and power-saving mode (U0, U1, U2, U3 or the like). When the normal operation mode is switched to the power-saving mode, the USB host 10 compares the usable current value in the power-saving mode in the USB port 103-1 or 103-2 with the actual use current value required in the power-saving mode of the USB device connected to the USB port 103-1 or 103-2, and determines the connection propriety of the UBS device. |
