| 摘要 |
PROBLEM TO BE SOLVED: To reduce the number of lines necessary for the connection of control devices.SOLUTION: A CPU 62 outputs an ENB signal in a high level via an ENB line 72 to a USB-IC 55, and after outputting the ENB signal, monitors the presence/absence of the overcurrent of the USB-IC 55 on the basis of the voltage level of the ENB line 72. When the ENB signal is input, the USB-IC 55 outputs a 5 V voltage to a VBUS line, and when overcurrent is generated, stops the output of the 5 V voltage to the VBUS line. A connection circuit 70 sets the voltage level of the ENB line 72 to a high level by using the 5 V voltage of the VBUS line, and when the output of the 5 V voltage is stopped, sets the voltage level of the ENB line 72 to a low level. Thus, it is possible to use the ENB line 72 for both the output of the ENB signal from the CPU 62 and the notification of overcurrent from the USB-IC 55. |
