ADV7170/ADV7171
APPENDIX 4—WIDE SCREEN SIGNALING
The ADV7170/ADV7171 support wide screen signaling (WSS) conforming to the standard. WSS data is transmitted on Line 23.
WSS data can only be transmitted when the ADV7170/ADV7171 are 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 58). 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 Bit C/W07 is set to a Logic Level 1, it enables the WSS data to be transmitted on Line 23. The latter portion of Line 23 (42.5 μs from the
HSYNC
falling edge of
) is available for the insertion of video.
Function of CGMS Bits
Bit 0 to Bit 2
Aspect Ratio/Format/Position
Bit 3 is odd parity check of Bit 0 to Bit 2
B0
0
B1
0
B2
0
B3
1
Aspect Ratio
4:3
Format
Position
Nonapplicable
Center
Full format
Letterbox
Letterbox
Letterbox
Letterbox
Letterbox
Full format
Nonapplicable
1
0
0
0
14:9
0
1
0
0
14:9
Top
1
1
0
1
16:9
Center
0
0
1
0
16:9
Top
1
0
1
1
>16:9
14:9
Center
0
1
1
1
Center
1
1
1
0
16:9
Nonapplicable
B4
0
1
B5
0
B9
0
1
0
1
B10
Camera Mode
Film Mode
0
0
1
1
No open subtitles
Subtitles in active image area
Subtitles out of active image area
Reserved
Standard Coding
1
B6
0
Motion Adaptive Color Plus
B11
0
1
No surround sound information
Surround sound mode
RESERVED
No Helper
1
B7
Modulated Helper
RESERVED
B12
B13
RESERVED
500mV
W0 W1 W2 W3 W4 W5 W6 W7 W8 W9 W10 W11 W12 W13
RUN-IN
SEQUENCE
START
CODE
ACTIVE
VIDEO
11.0μs
38.4μs
42.5μs
Figure 58. WSS Waveform Diagram
Rev. C | Page 42 of 64
ADI [ ADI ]
