Rev. 1.0, 02/00, page 758 of 1141
27.1.1
Features
•
Horizontal sync signal separation: Stable separation is provided by the AFC, and complement
and mask functions are available.
•
AFC reference clock frequency: 576 or 448 times the frequency of the horizontal sync signal
can be selected.
•
Vertical sync signal separation: The masking and complement functions are available through
the V complement and mask counter.
•
The source for sync separation can be selected from three signals (five methods).
1. Composite video signal input from the CVin2 terminal (two methods)
2. Csync signal input from the Csync/Hsync terminal (two methods)
3. Vsync and Hsync signals that are input from the VLPF/Vsync and Csync/Hsync terminals,
respectively (one method)
•
Csync separation comparator: The slice level can be selected by register settings.
•
Polarity of the Csync/Hsync terminal input: The signal detection polarity can be selected.
•
Polarity of the VLPF/Vsync terminal input: The signal detection polarity can be selected.
•
Noise detection: Noise during one frame is counted and a noise detection interrupt is
generated when the count reaches the specified value.
•
Noise detection counter: The count is readable and is reset every other vertical sync signal
input.
•
Field detection: The odd or even field for interlace scanning is distinguished.
•
Reference Hsync signal for the AFC: The reference Hsync signal can be selected.
•
V complement and mask counter: The source for the counter clock (twice the frequency of the
horizontal sync signal) can be selected.
•
Internal Csync generator: The clock source for the internal Csync generator can be selected.
27.1.2
Block Diagram
Figure 27.1 shows the block diagram of the sync separator.