| 摘要 |
PURPOSE:To automatically attain resynchronization by providing a reseting means resetting a frame synchronizing signal extracting section and a gate signal generating means from the result of comparison by a comparison means so as to eliminate a meaningless data when the out of synchronism takes place. CONSTITUTION:If the synchronization from the frame synchronizing signal extration section 3 is unlocked, no synchronizing signal comes at the timing when an AND gate 8 opens its gate. Thus, no output comes from the AND gate 8. Thus, the difference from the output of the gate 8 by a normal synchronizing signal from the signal extraction section 3 is detected by a comparison section 9, and a pulse is generated from a pulse generating section 10 by the detection signal. A reset section 11 resets the signal extraction section 3, a counter 6 and a delay section 2 to bring the signal extraction section 3 and the counter 6 into the standby state. Thus, when the synchronizing signal comes again, all the circuits are activated to extract the normal synchronizing signal. |
