| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a signal input circuit that is capable of reducing power consumption of a microcomputer and reducing power consumption of the signal input circuit when the microcomputer and the signal input circuit are formed as separate ICs. <P>SOLUTION: The signal input circuit includes: a clock signal switching circuit that outputs one of a first clock signal for a normal mode operation and a second clock signal for a sleep mode operation; and a terminal state detection circuit that detects occurrence of change in an acquired state of an input terminal. In a case where the terminal state detection circuit detects occurrence of change in the state of the input terminal, it outputs a switching request signal which instructs the clock signal switching circuit to output the first clock signal, and changes the operation mode to the normal mode if it is operating in the sleep mode, and outputs, to an arithmetic circuit, an operation request signal for allowing the arithmetic circuit to move to a normal operation mode in which the arithmetic circuit can input the state of the input terminal. <P>COPYRIGHT: (C)2013,JPO&INPIT |
