ADV7172 Datasheet, PDF (45/59 Pages) Analog Devices – Digital PAL/NTSC Video Encoder with Six DACs 10 Bits, Color Control and Enhanced Power Management

ADV7172/ADV7173
APPENDIX 4
WIDE SCREEN SIGNALING
The ADV7172/ADV7173 supports Wide Screen Signaling (WSS) conforming to the standard. WSS data is transmitted on Line 23.
WSS data can only be transmitted when the ADV7172/ADV7173 is configured in PAL mode. The WSS data is 14 bits long, the
function of each of these bits is as shown below. The WSS data is preceded by a run-in sequence and a Start Code (see Figure 71).
The bits are output from the configuration registers in the following order: C/W20 = W0, C/W21 = W1, C/W22 = W2, C/W23 = W3,
C/W24 = W4, C/W25 = W5, C/W26 = W6, C/W27 = W7, C/W10 = W8, C/W11 = W9, C/W12 = W10, C/W13 = W11, C/W14 = W12,
C/W15 = W13. If the Bit C/W07 is set to a Logic “1” it enables the WSS data to be transmitted on Line 23. The latter portion of
Line 23 (42.5 µs from the falling edge of HSYNC) is available for the insertion of video.
Function of CGMS Bits
Bit 0–Bit 2
Aspect Ratio/Format/Position
Bit 3 is odd parity check of Bit 0–Bit 2
B0 B1 B2 B3
0001
1000
0100
1101
0010
1011
0111
1110
Aspect Ratio
4:3
14:9
14:9
16:9
16:9
>16:9
14:9
16:9
Format
Full Format
Letterbox
Letterbox
Letterbox
Letterbox
Letterbox
Full Format
Nonapplicable
Position
Nonapplicable
Center
Top
Center
Top
Center
Center
Nonapplicable
B4
0
Camera Mode
1
Film Mode
B5
0
Standard Coding
1
Motion Adaptive Color Plus
B6
0
No Helper
1
Modulated Helper
B7
RESERVED
B9 B10
00
10
01
11
B11
0
1
B12
B13
No Open Subtitles
Subtitles In Active Image Area
Subtitles Out of Active Image Area
Reserved
No Surround Sound Information
Surround Sound Mode
RESERVED
RESERVED
500mV
RUN-IN
SEQUENCE
START
CODE
W0 W1 W2 W3 W4 W5 W6 W7 W8 W9 W10 W11 W12 W13
ACTIVE
VIDEO
11.0␮s
38.4␮s
42.5␮s
Figure 71. WSS Waveform Diagram
REV. A
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