| 摘要 |
A digital television system in which digital television signals are received whi ch comprise sequential digital words including a word designating a frame signal, which digi tal television system comprises a circuit for formatting digital television for use in the syst em, including a frame sync circuit, a sync word detection circuit for receiving digital televisi on signals from the formatting circuit for monitoring the digital televisions and providing a frame signal output when a word corresponding to the frame signal is detected, a sync confidence cou nter circuit for receiving the frame signal output from the sync word detection circuit, and adap ted when enabled, to be incremented by the receipt of the frame signal and decremented by the absence of a frame signal, the sync confidence circuit providing a sync lock signal to t he formatting circuit when a preset count is reached, and a frame counter circuit for receiving the di gital television signals and providing an enable signal to the sync confidence circuit when a fra me count is reached. |
