CIRCUIT FOR DETECTING A SYNCHRONIZING SIGNAL

摘要

A circuit for detecting a synchronizing signal comprises a gate circuit (35) to which reproduced synchronizing signal (SYNC) and window signal (LMASK) are supplied. A first counter (36, 40) which is synchronized with output signal (MSYNC) from the gate circuit (35) counts a clock signal (PLC) formed from reproducing signal and generates an insertion synchronizing signal (ISYNC). A second counter (37, 41) which is synchronized with output signal from the gate circuit (35) counts a fixed clock signal (FIC) and generates the window signal (LMASK). The output signal (MSYNC) from the gate circuit (35) or the insertion synchronizing signal (ISYNC) is made a synchronizing detection signal thereby the frame synchronizing signal can be detected stably.