| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a semiconductor integrated circuit in which an input signal such as a reset signal is inputted asynchronously with a clock signal externally, wherein noise intruded in the input signal is eliminated with high accuracy. <P>SOLUTION: The semiconductor integrated circuit includes: a system clock signal generating circuit for starting production of a system clock signal when an external input signal outputted from an input circuit is activated; a plurality of flip-flops a first stage flip-flop of which samples the external input signal synchronously with the system clock signal and which sequentially propagate the signal obtained by the sampling and are in cascade connection; a sampling circuit including a logic circuit for activating an internal input signal supplied to an internal circuit when the external input signal outputted from the input circuit and an output signal of a final stage flip-flop are activated; and a control circuit for discriminating whether or not the external input signal is activated by noise on the basis of the internal input signal. <P>COPYRIGHT: (C)2008,JPO&INPIT |
