| 摘要 |
<p>Flywheel phasing is enabled only during times in which phasing is required and in which the synchronization information, in the form of timing reference code words in an input signal, has been processed according to a set of parameters and determined to be relatively free of noise or disturbances. The flywheel phasing is normally disabled. A phase change detector continuously monitors the phase relationship of the flywheel and the input sync and, on finding a difference, initiates a re-phasing signal. A microprocessor monitors detecting stability of the input video data and if the data is stable, it then enables the flywheel phasing for a short time, and disables it again as soon as the flywheel gets rephased, the stability detecting circuits process timing reference code words of the incoming signal to determine certain conditions, such as whether the incoming data clock is present, whether the sync information is present, or a determination of error rates in the incoming sync. The results of processing are available to the microprocessor before the new phase or re-phasing message arrives. If the error rates are sufficiently low, the phasing is enabled long enough to get the flywheel circuit phased, after which it is disabled.</p> |
