Rev. 1.0, 02/00, page 733 of 1141
26.15
Sync Signal Detector
26.15.1
Overview
This block performs detection of the horizontal sync signal (Hsync) and vertical sync signal
(Vsync) from the composite sync signal (Csync), noise counting, and field detection.
It detects the horizontal and vertical sync signals by setting threshold in the register and based on
the servo clock (
φ
s = fosc/2). Noise masking is possible during the detection of the horizontal
sync signals, and if any Hsync pulse is missing, it can be supplemented. Also, if total volume of
the noise detected in one frame of Csync amounted over a specified volume, the detector generates
a noise detection interrupt.
Note:
This circuit detects a pulse with a specific width set by the threshold register. It does not
classify or restore the sync signal to a formal one.