| 摘要 |
<p>PURPOSE:To minimize the scale of a competitive type synchronization protecting circuit. CONSTITUTION:Disagreement pulse signal a and coincidence pulse signal b from a synchronization detecting circuit are used as input, the forward protecting counter 3 for counting up the disagreement pulse and the forward/backward protecting counter 4 for counting up coincidence pulse b are installed. This synchronization protecting circuit is provided with a selector circuit 5 for switching the application of forward/backward protecting counters 4 to the forward protection or to the backward protection using the hunting pulse c that is generated by output signals from these counters 3 and 4. Accordingly, by switching the forward/backward protecting counter 4 that is in frame synchronizing operation to the selector circuit 5 using the hunting pulse, the counter circuit can be omitted and the circuit scale can be made small.</p> |
