ADV7181B
Rev. B | Page 79 of 100
Bits
Subaddress
Register
Bit Description
7
6 5
4
3 2
1
0 Comments Notes
CMG[11:8]. Chroma manual gain can
be used to program a desired
manual chroma gain. Reading back
from this register in AGC mode gives
the current gain.
0
1
0
0
CAGC[1:0]
settings
decide in which
mode CMG[11:0]
operates.
Reserved.
1
1
Set to 1
0
0
Slow (TC = 2 sec)
0
1
Medium (TC = 1 sec)
1
0
Fast (TC = 0.2 sec)
0x2D
Chroma
Gain
Control 1
CAGT[1:0]. Chroma automatic gain
timing allows adjustment of the
chroma AGC tracking speed.
1
1 Adaptive
Has an effect only if
CAGC[1:0] is set to
auto gain (10).
0x2E Chroma
Gain
Control 2
CMG[7:0]. Chroma manual gain
lower 8 bits. See CMG[11:8] for
description.
0
0
0
0
0
0
0
0
CMG[11:0] = 750d; gain is
1 in NTSC
CMG[11:0] = 741d; gain is
1 in PAL
Min value is 0 d
(G = –60 dB)
Max value is 3750
(Gain = 5).
LMG[11:8]. Luma manual gain can
be used to program a desired
manual chroma gain, or to read
back the actual gain value used.
x
x
x
x
LAGC[1:0] settings decide
in which mode LMG[11:0]
operates
Reserved.
1
1
Set to 1
0
0
Slow (TC = 2 sec)
0
1
Medium (TC = 1 sec)
1
0
Fast (TC = 0.2 sec)
0x2F Luma
Gain
Control 1
LAGT[1:0]. Luma automatic gain
timing allows adjustment of the
luma AGC tracking speed.
1
1 Adaptive
Has an effect only if
LAGC[1:0] is set to
auto gain (001, 010,
011, or 100).
0x30 Luma
Gain
Control 2
LMG[7:0]. Luma manual gain can be
used to program a desired manual
chroma gain or read back the actual
used gain value.
x
x
x
x
x
x
x
x
LMG[11:0] = 1234d; gain is
1 in NTSC LMG[11:0] =
1266d; gain is 1 in PAL
Min value
NTSC 1024 (G = 0.85),
PAL (G = 0.81).
Max value
NTSC 2468 (G = 2),
PAL = 2532 (G = 2).
0x31 Reserved.
0
1
0
Set to default
0
Start of line relative to HSE
HSE = Hsync end.
HVSTIM. Selects where the VS signal
is asserted within a line of video.
1
Start of line relative to HSB
HSB = Hsync begin.
0
EAV/SAV
codes
generated
to suit ADI encoders
NEWAVMODE. Sets the EAV/SAV
mode.
1
Manual VS/field position
controlled by registers
0x32, 0x33, and 0xE5–0xEA
VS and
FIELD
Control 1
Reserved.
0
0
0
Set to default
Reserved.
0
0
0
0
0
1
Set to default
VSBHE.
0
VS goes high in the middle
of the line (even field)
1
VS changes state at the
start of the line (even field)
VSBHO.
0
VS goes high in the middle
of the line (odd field)
0x32 Vsync
Field
Control 2
1
VS changes state at the
start of the line (odd field)
NEWAVMODE bit
must be set high.
Reserved.
0
0
0
1
0
0
Set to default
VSEHE.
0
VS goes low in the middle
of the line (even field)
1
VS changes state at the
start of the line (even
field)
0
VS goes low in the middle
of the line (odd field)
0x33 Vsync
Field
Control 3
VSEHO.
1
VS changes state at the
start of the line (odd field)
NEWAVMODE bit
must be set high.
