| 摘要 |
<p>A change-over switch (6) is disposed on a line of a peripheral device (1). The change-over switch is controlled by a control unit (5a) provided within a USB controller (5). When a host discontinues a polling operation to the peripheral device, the peripheral device first opens the circuit of the change-over switch so as to decrease the potential at a point of the host to substantially the same potential of a ground line (G). Then, the peripheral device closes the circuit of the change-over switch to increase the potential at the point to be close to a power supply voltage. Accordingly, the host determines that the peripheral device is reconnected to the host, and starts the polling operation. <IMAGE> <IMAGE></p> |
