Philips Semiconductors
Preliminary specification
PAL/NTSC/SECAM video decoder with adaptive PAL/NTSC
comb filter, VBI-data slicer and high performance scaler
SAA7114H
8.5.5
DATA STREAM CODING AND REFERENCE SIGNAL
GENERATION (SUBADDRESSES 84H, 85H AND 93H)
If ITU 656 like codes are not wanted, these codes can be
suppressed in the output stream.
As H and V reference signals are logic 1, active gate
signals are generated, which are framing the transfer of
the valid output data. Alternative to the gates, H and V
trigger pulses are generated on the rising edges of the
gates.
As further option, it is possible to provide the scaler with a
gating external signal on pin ITRDY. So it is possible to
hold the data output for a certain time and to get valid
output data in bursts of a guaranteed length.
The sketched reference signals and events can be
mapped to the I-port output pins IDQ, IGPH, IGPV,
IGP0 and IGP1. For flexible use the polarities of all the
outputs can be modified. The default polarity for the
qualifier and reference signals is logic 1 (= active).
Due to the dynamic FIFO behaviour of the complete scaler
path, the output signal timing has no fixed timing relation
to the real-time input video stream. So fixed propagation
delays, in therms of clock cycles, related to the analog
input can not be defined.
Table 18 shows the relevant and supported SAV and EAV
coding.
The data stream is accompanied by a data qualifier.
Additionally invalid data cycles are marked with code 00H.
Table 18 SAV/EAV codes on I-port
SAV/EAV CODES ON I-PORT(1) (HEX)
MSB(2) OF SAV/EAV BYTE = 0 MSB(2) OF SAV/EAV BYTE = 1
EVENT DESCRIPTION
COMMENT
FIELD ID = 0
FIELD ID = 1
FIELD ID = 0
FIELD ID = 1
Next pixel is FIRST pixel of any
active line
0E
49
80
C7
HREF = active;
VREF = active
Previous pixel was LAST pixel
of any active line, but not the
last
13
54
9D
DA
HREF = inactive;
VREF = active
Next pixel is FIRST pixel of any
V-blanking line
25
38
62
7F
AB
B6
EC
F1
HREF = active;
VREF = inactive
Previous pixel was LAST pixel
of the last active line or of any
V-blanking line
HREF = inactive;
VREF = inactive
No valid data, don’t capture
and don’t increment pointer
00
IDQ pin inactive
Notes
1. The leading byte sequence is: FFH-00H-00H.
2. The MSB of the SAV/EAV code byte is controlled by:
a) Scaler output data: task A MSB = CONLH (90H[7]); task B
b) VBI-data slicer output data: DID[5:0]5DH[5:0] = 3EH
MSB = CONLH (C0H[7]).
MSB = 1; DID[5:0]5DH[5:0] = 3FH
MSB = 0.
2000 Mar 15
55
NXP [ NXP ]
