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Filename:
SAA7115_Datasheet.fm
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Last edited by H. Lambers
Philips Semiconductors
CS-PD Hamburg
CVIP2
Datasheet
SAA7115
Date:
10/23/01
Version:
0.67
8.4
VBI-data decoder and capture (subaddresses 40H to 7FH)
The SAA7115 contains a versatile VBI-data decoder and the option of reading back sliced VBI data for low bitrate
standards.
8.4.1
VBI D
ATA
S
LICER
The circuitry recovers the actual clock phase during the clock run-in period, slices the data bits with the selected data
×
56 bytes
(2
×
14 Dwords).
The VBI data slicing is controlled by the programming registers 40H to 5DH. Register 40H and 58H are controlling the
slicing process itself. The Line Control Registers (LCR registers) 41H to 57H are defining the data type (VBI data
standard) to be decoded. The data type is specified on a line by line basis for the lines two to 23 separately for even and
odd field and depends additionally on the detected video standard (i.e. whether the incoming video is a 50Hz / 625 lines
or 60Hz / 525 lines signal).
The definition for line control register LCR24 is valid for the rest of the corresponding field, normally no text data (video
data) should be selected there (LCR24_[7:0] = FFH) to stop the activity of the VBI-data slicer during active video.
The supported VBI-data standards are shown in Table 18 for 60Hz / 525 lines signals and 19 for 50Hz / 625 lines signals.
Table 18
60Hz / 525 Lines VBI Data types supported by the data slicer block
Data type
60Hz / 525 Lines VBI Data Standards
No.
binary
DESCRIPTION
Data rate
(Mbits/s)
FRAMING
CODE
FRAMING
CODE
WINDOW
Hamming
check
Decoder
output data
format
0
1
2
0000
0001
0010
do not acquire (active video)
US Teletext (WST525)
NABTS
Moji
-
-
-
-
Y-C
B
-C
R
4:2:2
raw data
raw data
raw data
5.7272
5.7272
5.7272
0x27
WST525
NABTS
MOJI
always
optional
-
programmable
programmable
(1)
3
0011
1.
should be set to 0x47 for Moji
4
0100
US Closed Caption (CC525,
Line21)
US Wide Screen Signalling
(WSS525, CGMS)
VITC525
Gemstar2x
Gemstar1x
reserved
Open1 (5 MHz)
Open2 (5,7272 MHz)
reserved
do not acquire (RAW)
do not acquire (Test)
do not acquire (active video)
0.503
001 binary
CC525
-
raw data
5
0101
0.447443
10 binary
WSS525
-
raw data
6
7
8
9
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
1.7898
1.007
0.503
-
5
5.7272
-
-
-
-
10 binary
0x4ED
001 binary
-
programmable
programmable
-
-
-
-
VITC525
4ED H
-
-
-
-
-
-
-
-
-
-
raw data
raw data
raw data
reserved
raw data
raw data
reserved
raw data
reserved
Y-C
B
-C
R
4:2:2
-
10
11
12
13
14
15
8-16us
8-16us
-
-
-
-