| 摘要 |
PURPOSE:To surely detect a correct header even when a same pattern as that of the header is included in a data in mistake in the header detection circuit detecting the header added to the head of the data inputted in the unit of frames. CONSTITUTION:When a comparator section 1 detects a header pattern in a data D1, the section 1 outputs a coincidence detection pulse P1. A 1-frame delay section 3 delays the coincidence detection pulse P1 outputted from the comparator section 1 by one frame. An AND gate AND receives pulses P1, P2 simultaneously from the comparator section 1 and the one-frame delay section 3 outputs a pulse P3. A header number calculation counter 4 counts number of pulses P3 outputted from the AND gate AND and outputs a processing start pulse P5 representing the detection of the header when the count reaches a prescribed value or over. |
