LG CRD-8402B Service Manual page 23

• GTOP monitors the state of Frame Sync protection. ("H" : Sync protection window released)
• XPLCK is an inversion of the EFM PLL clock. The PLL is designed so that the falling edge of XPLCK
coincides with a change point of the EFM signal.
• RFCK is a signal generated at 136-µs periods using a crystal oscillator.
• LOCK is sampling the GFS at 460Hz and outputs "H" when GFS is "H".
("L" outputs when "L" is output eight times in succession or inputs when LKIN is "H".)
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