| 摘要 |
<p>PURPOSE:To generate a window with high accuracy by operating a system counter, based on a clock which is extracted from a data string by a PLL circuit, in a reproducing period of a data area, and also, based on a clock from a crystal oscillator, in a reproducing period of other area. CONSTITUTION:In a period in which a data area on a format is being reproduced, a system counter which is constituted of a PLL system counter 13, a crystal system counter 20, a block counter 21 and a state counter 22 and manages a system is operated, based on a clock which is extracted from a data string by a PLL circuit 3. On the other hand, in a period in which other area than the data area is being reproduced, the system counter is operated, based on a clock from a crystal oscillator 30. In such a way, an actual running position of a tape is detected exactly, and a window of a data sync having a correct width and an ATF (Automatic Track Finding) sync can be generated.</p> |
