tw9910 ETC-unknow, tw9910 Datasheet - Page 12

• Manufacturer Part Number: tw9910
• Description: Power Ntsc/pal/secam Video Decoder With Slicer
• Manufacturer: ETC-unknow

TW9910
VBI Data Processing
TECHWELL, INC.
Raw VBI data output
TW9910 supports raw VBI data output. Raw VBI data output has the same vertical line delay timing as
video output. Horizontal output timing is also programmable by VBIDELAY register. Raw VBI data is
generated during HACTIVE active period (from SAV to EAV) as Video data output. Total pixel number
of raw VBI data per line is twice as many as HACTIVE register value. If VBI EN register is set to “1”, all
vertical blanking output while VACTIVE is inactive will be raw VBI data output. If VVBI registers are set
to more than “1”, the VVBI number lines from top video active lines will also be raw VBI data output
lines.
VBI Data Slicer
The following VBI standards are supported by VBI Data slicer. The VBI Data slicing is controlled by the
registers LCTL6 to LCTL26. Registers LCTL6 to LCTL26 are controlling the slicing process itself.
LCTL6 to LCTL26 defines the Data Type to be decoded. The Data Type can be specified on a line by
line basis for line6 to line26 and for even and odd field depending on the detected TV system standard.
The setting for LCTL26 is valid for the rest of the corresponding field. Normally no text data 0H (video
data) should be selected to render the VBI Data slicer inactive during active video. LCTRL26 is useful
for Full-Field Teletext mode in the case of NABTS.
NABTS is 525 Teletext-C. Japan’s MOJI is 525 Teletext-D. Didon Antiope is 625 Teletext-A. VBI Data
slicer supports up to Physical layer, Link layer in ITU-R BT.653-2. Japan’s EIAJ CPR-1204 shown as
525 WSS has the same physical layer protocol as that of CGMS.
The sliced VBI data is embedded in the ITU-R BT.656 output stream, using the intervals between the
End of Active Video (EAV) and the Start of Active Vide(SAV) codes of each line and formatted
according to ITU-R BT.1364 Ancillary data packet Type 2.
Table 5. VBI Standard.
STANDARD TYPE TV Systems
625 Teletext-B
525 Teletext-B
625 Teletext-C
525 Teletext-C
625 Teletext-D
525 Teletext-D
625 CC
525 CC
625 WSS
525 WSS(CGMS)
625 VITC
525 VITC
Gemstar 2x
Gemstar 1x
VPS
625 Teletext-A
(lines/freq)
625/50
525/60
625/50
525/60
625/50
525/60
625/50
525/60
626/50
525/60
625/50
525/60
525/60
525/60
625/50
625/50
12
Bit Rate
(Mbits/s)
6.9375
5.727272
5.734375
5.727272
5.6427875
5.727272
0.500
0.503
5
0.447443
1.8125
1.7898
1.007
0.503
5
6.203125
NRZ
NRZ
Modulation
NRZ
NRZ
NRZ
NRZ
NRZ
NRZ
NRZ
NRZ
Bi-phase
NRZ
NRZ
NRZ
Bi-phase
NRZ
Low Power NTSC/PAL/SECAM
Video Decoder with VBI Slicer
Data Type
1H
1H
2H
2H
3H
3H
4H
4H
5H
5H
6H
6H
7H
8H
9H
AH
09/21/2006
REV.
A