摘要 |
A synchronizing signal generator produces a PAL standard horizontal synchronizing signal using a PAL standard subcarrier signal as a timing reference. The synchronizing signal period is not an even multiple of the subcarrier signal period. To produce the synchronizing (sync) signal, the generator first frequency multiplies and divides the input signal to produce a reference signal having a period that is a rational multiple of the subcarrier signal period but smaller than the desired sync signal period. The generator then delays each successive pulse of the reference signal by increasingly longer delay times to produce the sync signal. |