SAA7129AH/V1,557 Trident Microsystems, Inc., SAA7129AH/V1,557 Datasheet - Page 12
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SAA7129AH/V1,557
Manufacturer Part Number
SAA7129AH/V1,557
Description
Manufacturer
Trident Microsystems, Inc.
Datasheet
1.SAA7129AHV1557.pdf
(55 pages)
Specifications of SAA7129AH/V1,557
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Philips Semiconductors
7.7
The synchronization of the SAA7128AH; SAA7129AH is
able to operate in two modes; slave mode and master
mode.
In master mode (see Fig.19), the circuit generates all
necessary timings in the video signal itself, and it can
provide timing signals at the RCV1 and RCV2 ports.
In slave mode, it accepts timing information either from the
RCV pins or from the embedded timing data of the
ITU-R BT.656 data stream.
For the SAA7128AH; SAA7129AH, the only difference
between master and slave mode is that it ignores the
timing information at its inputs in master mode. Thus, if in
slave mode, any timing information is missing, the IC will
continue running free without a visible effect. But there
must not be any additional pulses (with wrong phase)
because the circuit will not ignore them.
In slave mode (see Fig.18), an interface circuit decides,
which signal is expected at the RCV1 port and which
information is taken from its active slope. The polarity can
be chosen. If PRCV1 is logic 0, the rising slope will be
active.
The signal can be:
On the RCV2 port, the IC can provide a horizontal pulse
with programmable start and stop phase; this pulse can be
inhibited in the vertical blanking period to build up, for
example, a composite blanking signal.
The horizontal phase can be set via a separate input
RCV2. In the event of VS pulses at RCV1, this is
mandatory. It is also possible to set the signal path to blank
via this input.
From the ITU-R BT.656 data stream, the SAA7128AH;
SAA7129AH decodes only the start of the first line in the
odd field. All other information is ignored and may miss.
If this kind of slave mode is active, the RCV pins may be
switched to output mode.
2003 Dec 09
A Vertical Sync (VS) pulse; the active slope sets the
vertical phase
An odd/even signal; the active slope sets the vertical
phase, the internal field flag to odd and optionally sets
the horizontal phase
A Field Sequence (FSEQ) signal; it marks the first field
of the 4 (NTSC), 8 (PAL) respectively 12 (SECAM) field
sequences. In addition to the odd/even signal, it also
sets the PAL phase and optionally defines the subcarrier
phase.
Digital video encoder
Synchronization
12
In slave mode, the horizontal trigger phase can be
programmed to any point in the line, the vertical phase
from line 0 to line 15 counted from the first serration pulse
in half line steps.
Whenever synchronization information cannot be derived
directly from the inputs, the SAA7128AH; SAA7129AH will
calculate it from the internal horizontal, vertical and PAL
phase. This gives good flexibility with respect to external
synchronization, but the circuit does not suppress illegal
settings. In such an event, the odd/even information may
vanish as it does in the non-interlaced modes.
In master mode, the line lengths are fixed to 1728 clocks
at 50 Hz and 1716 clocks at 60 Hz. To allow
non-interlaced frames, the field lengths can be varied by
SAA7129AH does not provide odd/even information and
the output signal does not contain the PAL ‘Bruch
sequence’.
At the RCV1 pin the IC can provide:
At the RCV2 pin, there is a horizontal pulse of
programmable phase and duration available. This pulse
can be suppressed in the programmable inactive part of a
field, giving a composite blank signal.
The directions and polarities of the RCV ports can be
chosen independently. Timing references can be found in
Tables 52 and 60.
7.8
The input to LLC1 can either be an external clock source
or the buffered on-chip clock XCLK. The internal crystal
oscillator can be run with either a 3rd-harmonic or a
fundamental crystal frequency.
7.9
The I
supporting 7-bit slave addresses and 400 kbits/s
guaranteed transfer rate. It uses 8-bit subaddressing with
an auto-increment function. All registers are write and
readable, except one read only status byte.
The I
(SA) tied LOW and as 8CH with pin 21 (SA) tied HIGH.
0.5 lines. In the event of non-interlace, the SAA7128AH;
A Vertical Sync (VS) signal with 2.5 (50 Hz) or 3 (60 Hz)
lines duration
An odd/even signal which is LOW in odd fields
A Field Sequence (FSEQ) signal which is HIGH in the
first field of the 4, 8 respectively 12 field sequences.
2
2
C-bus interface is a standard slave transceiver,
C-bus slave address is defined as 88H with pin 21
Clock
I
2
C-bus interface
SAA7128AH; SAA7129AH
Product specification