| 摘要 |
An input-output I/F has a pull-up register 38 whose one end is connected to signal line of D+terminal and other end is connected to a power line and a controlling unit for controlling effectiveness of connection between the power line and the other end of the pull-up register. The controlling unit makes pull-up of the pull-up register ineffective, breaking connection between the power line and the other end of the pull-up register, in accordance with an instruction of switching USB class from a first state of a first USB class to a second state of a second USB class different from the first USB class, and when the USB class has been switched to the second state of the second USB class, the controlling unit makes pull-up of the pull-up register effective again, making connection between the power line and the other end of the pull-up register.
|
