2004 Mar 16
95
Philips Semiconductors
Product specification
PC-CODEC
SAA7108E; SAA7109E
10.4.1
X
PORT CONFIGURED AS OUTPUT
If the data output is enabled at the expansion port, then the
data stream from the decoder is present. The data format
of the 8-bit data bus is dependent on the chosen data type
which is selectable by the line control registers LCR2
to LCR24; see Table 33. In contrast to the image port, the
sliced data format is not available on the expansion port.
Instead, raw CVBS samples are always transferred if any
sliced data type is selected.
Detailsofsomeofthedatatypesontheexpansionportare
as follows:
Active video
: (data type 15) contains components
Y-C
B
-C
R
4 : 2 : 2 signal, 720 active pixels per line. The
amplitude and offsets are programmable via
DBRI7 to DBRI0, DCON7 to DCON0,
DSAT7 to DSAT0, OFFU1, OFFU0, OFFV1 and
OFFV0. For nominal levels see Fig.25.
Test line
: (data type 6) is similar to the active video
format, with some constraints within the data
processing:
– adaptive chrominance comb filter, vertical filter
(chrominance comb filter for NTSC standards, PAL
phase error correction) within the chrominance
processing are disabled
– adaptive luminance comb filter, peaking and
chrominance trap are bypassed within the luminance
processing.
This data type is defined for future enhancements. It can
be activated for lines containing standard test signals
within the vertical blanking period. Currently most
sources do not contain test lines. For nominal levels
see Fig.25.
Raw samples
(data types 0 to 5 and 7 to 14): C
B
-C
R
samples are similar to data type 6, but CVBS samples
aretransferredinsteadofprocessedluminancesamples
within the Y time slots.
The amplitude and offset of the CVBS signal is
programmable via RAWG7 to RAWG0 and
RAWO7 to RAWO0, see Chapter 18,
Tables 174 and 175. For nominal levels see Fig.26.
The relationship of LCR programming to line numbers is
described in Section 9.2; see Tables 34 to 37.
The data type selections by LCR are overruled by setting
OFTS2 = 1 (subaddress 13H bit 2). This setting is mainly
intended for device production testing. The VPO-bus
carries the upper or lower 8 bits of the two ADCs
depending on the OFTS[1:0] 13H[1:0] settings; see
Table 169. The output configuration is done via
MODE[3:0] 02H[3:0] settings; see Table 151. If a Y/C
mode is selected, the expansion port carries the
multiplexed output signals of both ADCs, in CVBS mode
the output of only one ADC. No timing reference codes are
generated in this mode.
Remark
: The LSBs (bit 0) of the ADCs are also available
on pin RTS0; see Table 167.
The SAV/EAV timing reference codes define the start and
end of valid data regions. The ITU-blanking code
sequence ‘- 80 - 10 - 80 - 10 -...’ is transmitted during the
horizontal blanking period, between EAV and SAV.
The position of the F bit is constant according to ITU 656;
see Tables 60 and 61.
The V bit can be generated in two different ways (see
Tables 60 and 61) controlled via OFTS1 and OFTS0; see
Table 169.
F and V bits change synchronously with the EAV code.
Table 58
Data format on the expansion port
Notes
1.
The generation of the timing reference codes can be suppressed by setting OFTS[2:0] to ‘010’; see Table 169. In
this event the code sequence is replaced by the standard ‘- 80 - 10 -’ blanking values.
If raw samples or sliced data are selected by the line control registers (LCR2 to LCR24), the Y samples are replaced
by CVBS samples.
2.
BLANKING
PERIOD
TIMING
REFERENCE
CODE (HEX)
(1)
720 PIXELS Y-C
B
-C
R
4 : 2 : 2 DATA
(2)
TIMING
REFERENCE
CODE (HEX)
(1)
BLANKING
PERIOD
...
80
10
FF 00 00 SAV C
B
0 Y0 C
R
0 Y1 C
B
2 Y2 ... C
R
718 Y719 FF 00 00 EAV 80
10
...