| 摘要 |
An arrangement is provided for developing timed clock signals for a digital baseband television signal processing system. An AFPC loop circuit is responsive to the color burst signal component of a received analog video signal for producing a continuous wave signal which is aligned in frequency and phase with the color burst signal. The continuous wave signal is applied to a tint control circuit, which is responsive to a control signal, for variably shifting the phase of the continuous wave signal. The phase-shifted continuous wave signal is then applied to a phase-locked loop circuit, which produces a sampling signal for an analog-to-digital converter at a frequency which is a multiple of the color subcarrier frequency and with a phase which will result in a reproduced image of a desired tint or hue. In one embodiment of the present invention, the continuous wave signal is phase-shifted by a series of logic gates having a plurality of output taps. A multiplexer selects a signal of a desired phase shift from one of the output taps, which signal is then applied to the phase-locked loop circuit for generation of the sampling signal.
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