| 摘要 |
PROBLEM TO BE SOLVED: To provide a digital noise filter capable of coping with the noise state of various signals and attaining reduction in circuit scale.SOLUTION: The digital noise filter includes a timing generation circuit 6, capable of adjusting a time interval by a previous-state capturing interval setting value and outputting timing at the time interval; a previous-state holding FF 1 for capturing an external input signal every time a timing signal is output from the timing generation circuit 6; a state comparator 2 for comparing the match of a state held by the previous state holding FF 1 with a present external input signal state; a number counter of coincidence counter 3 for counting the number of times of the match in the state comparator 2, by timing output by the timing generation circuit 6; a number counter of coincidence comparator 4 for outputting a match signal, when the counter value of the match number counter 3 matches with or is larger than a counter-limit set value; and a reading FF 5 for capturing the output of the previous state holding FF 1 by the output of the matching number comparator 4. |
