| 摘要 |
There are provided an output terminal P1 to be also used as a terminal to which a USB signal line is connected, a power-on reset circuit 80 for generating a reset signal RES in response to power supply from the USB signal line, and an RC oscillator 81 for starting oscillation immediately in response to the reset signal RES. The output of the RC oscillator 81 is used for a system clock to operate a microcomputer and to set the level of the output terminal P1. Consequently, USB signal lines 110 and 111 are forcibly set to a level in a non-connection state for a period before a USB interface circuit 30 can respond to a bus reset signal sent from a host.
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