| 摘要 |
A digital color burst phase switch for determining phase shift of a color burst signal in a PAL video signal includes a phase selector for selecting either a first reference clock or a second reference clock in response to a PAL switch signal. A phase delay device delays the phase of either the first reference clock or the second reference clock selected by the phase selector to generate a third reference clock. A phase comparator compares the phase of the third reference clock to the phase of the color burst signal to generate a control signal. The control signal is integrated over substantially the entire color burst signal to generate an integration value. This integration value is compared to a threshold value in a threshold device to generate a correction signal. A PAL switch generator generates the PAL switch signal in response to the correction signal such that the phase selector selects either the first reference clock or the second reference clock having a phase substantially corresponding to the phase of the color burst signal.
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