S5L986F01 Datasheet, PDF (17/35 Pages) Samsung semiconductor – DIGITAL SIGNAL PROCESSOR FOR CDP

DIGITAL SIGNAL PROCESSOR FOR CDP
S5L986F01
FRAME SYNC DETECT/PROTECT/INSERT
• Frame Sync Detect
Data is composed of units of frame, and a frame is composed of frame sync, subcode data, audio data, and
redundancy data. This IC detects frame sync to maintain synchronization.
• Frame Sync Protect/Insert
There are some cases in which frame sync is not detected, or detected it from other data which does not include
frame sync, due to disc error or jitter. In these cases, the frame sync must be protected and inserted.
To protect frame sync, a window is made by WSEL of the CNTL-S register. The frame sync entering this window is
considered valid data, and the frame sync which leaves this window is ignored. If frame sync is not detected within
the frame sync protect window, insert instead the frame sync made in the internal counter. If frame sync is inserted
continuously, reaching the number of frames set by FSEM and FSEL of the CNTL-S register, the following occurs:
ULKFS becomes high, the frame sync protect window is ignored, and the frame sync detected next is accepted
unconditionally. When a frame sync is accepted, the ULKFS signal becomes L, and accepts the frame sync
detected within the window (refer to below Table).
LKFS
1
0
0
ULKFS
Comment
0 Play back frame sync and the generated sync coincide.
1) The play back frame sync and the generated frame sync do not coincide,
0
but PBFR sync is detected from within the window selected by WEL.
2) PBFR sync and XTFR sync do not coincide, and are not detected from within the window
selected by WSEL. Sync insert is carried out.
1) Immediately after the following situation: Frame sync is not detected within the window,
1
so frame is inserted in the amount set by CNTL-S registers FSEM and FSEL.
2) If PBFR sync is still undetected after 1).
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