| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a technique capable of determining a frequency of a data signal having mixed short and long pulse widths. <P>SOLUTION: A frequency determination circuit 201 for determining a frequency among a plurality of data signals of different frequencies includes a circuit for capturing a plurality of data signals of different frequencies and determines a frequency on the basis of the count of a signal having a pulse width shorter than a predetermined pulse width. For example, a signal having a pulse width shorter than the predetermined pulse width is detected, and the number of pulses of the detected signal is counted. According to a prepared correspondence between pulse count and frequency, a frequency can be determined on the basis of the count. <P>COPYRIGHT: (C)2012,JPO&INPIT |
