Philips Semiconductors
Preliminary specification
PAL/NTSC/SECAM video decoder with adaptive PAL/NTSC
comb filter, VBI-data slicer and high performance scaler
SAA7114H
8.4
VBI-data decoder and capture
(subaddresses 40H to 7FH)
The definition for line 24 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 SAA7114H contains a versatile VBI-data decoder.
The implementation and programming model accords to
the VBI-data slicer built in the multimedia video data
acquisition circuit SAA5284.
To adjust the slicers processing to the input signal source,
there are offsets in horizontal and vertical direction
available: parameters HOFF[10:0]5BH[2:0]59H[7:0],
VOFF[8:0]5BH[4]5AH[7:0] and FOFF[5BH[7]]).
The circuitry recovers the actual clock phase during the
clock run-in period, slices the data bits with the selected
data rate, and groups them to bytes. The result is buffered
into a dedicated VBI-data FIFO with a capacity of
2 × 56 bytes (2 × 14 Dwords). The clock frequency,
signals source, field frequency, accepted error count must
be defined in subaddress 40H.
Contrary to the scalers counting, the slicers offsets are
defining the position of the H and V trigger events related
to the processed video field. The trigger events are the
falling edge of HREF and the falling edge of V123 from the
decoder processing part.
The relation of these programming values to the input
signal and the recommended values can be seen in
Tables 4 to 7.
The supported VBI-data standards are shown in Table 14.
For lines 2 to 24 of a field, per VBI line, 1 of 16 standards
can be selected (LCR24_[7:0] to LCR2_[7:0] in
57H[7:0] to 41H[7:0]: 23 × 2 × 4 bit programming bits).
Table 14 Data types supported by the data slicer block
DT[3:0]
62H[3:0]
DATA RATE
(Mbits/s)
FC
WINDOW
HAM
CHECK
STANDARD TYPE
FRAMING CODE
27H
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
teletext EuroWST, CCST
European closed caption
VPS
6.9375
WST625
CC625
VPS
always
0.500
001
5
9951H
wide screen signalling bits
US teletext (WST)
US closed caption (line 21)
(video data selected)
(raw data selected)
teletext
5
1E3C1FH
27H
WSS
5.7272
0.503
5
WST525
CC525
disable
disable
always
001
none
5
none
6.9375
programmable
programmable
programmable
general text optional
VITC625
VITC/EBU time codes (Europe) 1.8125
VITC/SMPTE time codes (USA) 1.7898
VITC625
reserved
programmable
programmable (A7H) Japtext
US NABTS
5.7272
NABTS
optional
MOJI (Japanese)
5.7272
Japanese format switch (L20/22)
5
5
programmable
none
open
no sliced data transmitted
(video data selected)
disable
2000 Mar 15
52
NXP [ NXP ]
