Rev. 1.0, 02/00, page 759 of 1141
Slicing v
oltage
control
Separ
ation
method
Digital H
separ
ation
counter
Vvth register
Selecting 576 or 448
as the division r
atio
Digital
LPF ON
Switching
Switching
Ref
erence
Hsync
Inter
nally gener
ated
Hsync
Exter
nal
Hsync
Switching
Switching
F
requency-dividing
counter
Complement and
mask setting register
Switching
Switching
Reset
for V
Reset
for H
TV f
o
rmat
in H
(Self-
running)
Inter
nal Csync
gener
ator
AFC error output
circuit
(compar
ator)
When the data slicer is used and the te
xt
displa
y mode is selected in the OSD
,
the AFC cloc
k is selected;
the cloc
k is
also used as the dot cloc
k.
When the data slicer is not used
and the te
xt displa
y mode is
selected in the OSD
, the
self-r
unning signal is selected.
Switching
Switching
Switching
Switching
Switching
Ref
erence cloc
k
Masking
Complement
and mask
Complement enab
le bit
(Self-r
unning)
Field detection windo
w
Field detection
Field detection
windo
w register
Hvth register
Noise
detection
Noise detection
windo
w
Noise
counter
Noise detection
interr
upt
: Register
V complement enab
led:
Complemented and
mask
ed V
V complement disab
led:
Mask
ed V
Exter
nal Vsync
(data
slicer)
Exter
nal Vsync
interr
upt
Field signal (data slicer)
Exter
nal Hsync
(data slicer)
Detection windo
w
signals f
or data slicer
(data slicer)
Inter
nally gener
ated
sync signal (OSD)
Cloc
k r
un-in per
iod and star
t bit per
iod
AFCH
Dot cloc
k (OSD)
Noise detection le
v
el register
Csync
separ
ation
compar
ator
I/O
s
witching
P
olar
ity
s
witching
P
olar
ity
s
witching
CVin2
Hsync
Vsync
Si/TEXT
HCKSEL
(TE)
(0)
(1)
(Si)
SEPH
1/2
U/D
inV
HHK
C
H complement and
mask counter
(complement and
mask functions)
R
OSCH
AFCV
Si/TEXT
SEPV
OSC2H
C
R
C
C
R
Digital V
separ
ation
counter
U/D
C
φ
/2
φ
/2
φ
/2
Csync/Hsync
Vsync/VLPF
(1)
(0)
(TE)
OSDFLD
OSD
V (OSD)
Si = AFCV
TEXT = inV
OSDH (OSD)
Field signal (OSD)
Si = AFCFLD
TEXT = inFLD
(TE)
(0)
(1)
inFLD
AFCFLD
(Si)
(Si)
Si/TEXT
HCKSEL
VCKSL
AFC2H 2
×
fh
4/2fsc
Si/TEXT
AFCosc
AFCpc
AFCLPF
AFC
(Si)
AFCH
AFC oscillator
HSEL
(TE)
V complement and
mask counter
(complement and
mask functions)
R
C
Figure 27.1 Sync Separator Block Diagram