| 摘要 |
PURPOSE:To exactly detect a frame synchronizing word even when a frame length is different, by providing the plural groups of synchronizing codes, and detecting a synchronizing signal in accordance with how many groups among them have been detected. CONSTITUTION:A data which has been received by a shift register 2 is shifted by the register 2 by a synchronizing pulse code length, outputted from both shift registers 1, 2, and whether it is the same code as synchronizing codes 1, 2 or not is compared by comparators 3, 4. When one of outputs of these comparators 3, 4 is coincident, it is outputted through an OR gate 5 as a synchronizing word, synchronized with a clock 1, and detected as a synchronizing pulse by a shift register 6. The detected synchronizing pulse is latched by a flip-flop 7 and outputted to the outside. By a shift controlling circuit 8, the shift quantity of the shift registers 1, 2 is controlled, so that the regenerative mistake of a receiving data does not occur. |
