| 摘要 |
<p>PURPOSE:To facilitate the recovery from mis-synchronization by providing another backward protection state between one backward protection and a synchronizing state to make the transition from the state of out of synchronism to the synchronizing state asymmetry with the transition from the synchronizing state into the state of out of synchronism. CONSTITUTION:The synchronizing state is stored in a register RG 18, decided and controlled by a state decision circuit ST 17 depending on the result of detection of a synchronizing pattern and the synchronizing state. When the synchronizing pattern is detected in the state of out of synchronism, the state is transferred to the 'backward protection 1' state and when the synchronizing pattern is detected in a correct timing succeedingly, the state is transferred to the state of 'backward protection 2', and when no pattern is detected, the state is restored to the state of 'out of synchronism'. When the synchronizing pattern is detected succeedingly after the transition to 'backward protection 2', the synchronizing state is attained. When no pattern is detected, however, the state is restored to the state of 'out of synchronism'.</p> |
