ADV7180
Bits (Shading Indicates Default
State)
Comments
LQFP-64 LFCSP-40
Subaddress Register
Bit Description
Notes
7
6
5
4
3
2
1
0
0x9B
Letterbox 1
(Read Only)
LB_LCT[7:0]. Letterbox
data register.
x
x
x
x
x
x
x
x
Reports the number of
black lines detected at the
top of active video
This feature examines the
active video at the start
and end of each field; it
enables format detection
even if the video is not
accompanied by a CGMS
or WSS sequence
0x9C
Letterbox 2
(Read Only)
LB_LCM[7:0]. Letterbox
data register.
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Reports the number of
black lines detected in the
bottom half of active video
if subtitles are detected
0x9D
0xB2
Letterbox 3
(Read Only)
LB_LCB[7:0]. Letterbox
data register.
x
x
Reports the number of
black lines detected at the
bottom of active video
CRC Enable
(Write Only)
Reserved.
0
0
Set as default
CRC_ENABLE. Enable
CRC checksum
decoded from CGMS
packet to validate
CGMSD.
0
1
Turn off CRC check
CGMSD goes high with
valid checksum
Reserved.
0
0
0
1
1
Set as default
0xC3
ADC SWITCH 1
MUX_0[3:0]. Manual
muxing control for
MUX0.
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
No connect
AIN1
No connect
AIN1
MAN_MUX_EN = 1
MAN_MUX_EN = 1
MAN_MUX_EN = 1
AIN2
No connect
No connect
AIN2
AIN3
This setting controls
which input is routed
to the ADC for
AIN4
AIN5
AIN3
processing.
AIN6
No connect
No connect
No connect
Reserved.
0
MUX_1[3:0]. Manual
muxing control for
MUX1.
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
No connect
No connect
No connect
AIN3
No connect
No connect
No connect
No connect
AIN2
This setting controls
which input is routed
to the ADC for
AIN4
AIN5
AIN3
processing.
AIN6
No connect
No connect
No connect
Reserved.
0
0xC4
ADC Switch 2
MUX_2[3:0]. Manual
muxing control for
MUX2.
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
No connect
No connect
AIN2
No connect
No connect
No connect
No connect
No connect
AIN3
No connect
No connect
AIN5
This setting controls
which input is routed
to the ADC for
processing.
AIN6
No connect
No connect
No connect
Reserved.
0
0
0
0
0
1
MAN_MUX_EN. Enable
manual setting of the
input signal muxing.
0
1
Disable
Enable
This bit must be set to 1 for
manual muxing
0xDC
0xDD
Letterbox Control 1
Letterbox Control 2
LB_TH [4:0]. Sets the
threshold value that
determines if a line is
black.
1
1
0
0
0
0
Default threshold for the
detection of black lines
Reserved.
1
0
0
1
1
0
Set as default
LB_EL[3:0]. Programs
the end line of the
activity window for LB
detection (end of field).
1
LB detection ends with the
last line of active video on a
field, 1100b: 262/525
LB_SL[3:0]. Program
the start line of the
activity window for LB
detection (start of
field).
0
Letterbox detection aligned
with the start of active video,
0100b: 23/286 NTSC
Rev. A | Page 92 of 112
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