| 摘要 |
PROBLEM TO BE SOLVED: To provide an EFM signal width detection circuit capable of detecting the signal width of the specific polarity of an EFM signal even when a regenerative signal is unstable. SOLUTION: This circuit is provided with an EFM rise and fall detection circuit 3 for detecting the rises and falls of the EFM signal by inputting a clock signal PCK that is asynchronous with the EFM signal, a counter circuit 8 for counting the period of the level of the specific polarity of the EFM signal, decoding circuits 9 to 11 for decoding the output of the circuit 8 with a specific count number, and a JK flip-flop 13 for using the output of the detection circuit 3 and the outputs of the decoding circuits 9 to 11 and performing set/reset while synchronizing with the clock signal, and detects the EFM signal width of a desired level by setting the count numbers of the decoding circuits. |
