| 摘要 |
PROBLEM TO BE SOLVED: To reduce unnecessary power consumption by a differential input buffer in an I/O buffer while a controller performs data transmission. SOLUTION: The USB controller 16 controls communication with another device according to USB standards. The I/O buffer 33 has output buffers 41A and 41B for outputting data transmitted from the USB controller 16 to another device, and the differential input buffer 43 for inputting a differential signal of data received from another device into the USB controller 16. A buffer control circuit 31 has a logic circuit for stopping the operation of the differential input buffer 43 with an H-level signal SUSP, while the USB controller 16 sends L-level signals DPOEZ and DMOEZ enabling data output to the output buffers 41A and 41B, when receiving the signals. COPYRIGHT: (C)2004,JPO
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