| 摘要 |
PURPOSE:To obtain a general-purpose marker signal detecting circuit by storing plural marker components inserted periodically in a specific information signal, and comparing the components with a preset bit pattern. CONSTITUTION:The marker signal (synchronizing signal) component inserted to the redundant part of a sound signal scrambled at the transmission side is extracted by an HPF12 and waveform-shaped by a comparator 13, then fed to a shift register circuit 14 comprising plural shift registers SR. A pulse pattern to be detected is set in comparators 15, 16 in advance and the pattern is compared with an output from a register circuit 14. The coincidence output from the comparator 15 is stored in registers 17, 18 and when the output is detected consecutively for 4 times, a marker detection output is obtained at an output of AND circuits 20, 21. The result is fed to a control circuit 5 of a sequence rearranging processing section 6 for scramble data. |
