Philips Semiconductors
Preliminary specification
PAL/NTSC/SECAM video decoder with adaptive PAL/NTSC
comb filter, VBI-data slicer and high performance scaler
SAA7114H
8.3.1.3
Output field processing
When OFIDC[90H[6]] = 1, the TOGGLE information is
available as output field ID on bit D6 of SAV and EAV,
respectively on pin IGP0 (IGP1), if FID output is selected.
As reference for the output field processing, two signals
are available for the back-end hardware.
Additionally the bit D7 of SAV and EAV can be defined via
CONLH[90H[7]]. CONLH[90H[7]] = 0 (default) sets D7 to
logic 1, a logic 1 inverts the SAV/EAV bit D7. So it’s
possible to mark the output of the both tasks by different
SAV/EAV codes. This bit can also be seen as ‘task flag’ on
the pins IGP0 (IGP1), if TASK output is selected.
These signals are the input field ID from the scaler source
and a TOOGLE flag, which shows, that an active task is
used an odd (1, 3, 5...) or even (2, 4, 6...) number of times.
Using a single or both tasks and reducing the field or frame
rate with the task handling functionality, the TOGGLE
information can be used, to reconstruct an interlaced
scaled picture at a reduced frame rate. The TOGGLE flag
isn’t synchronized to the input field detection, as it is only
dependent on the interpretation of this information by the
external hardware, whether the output of the scaler is
processed correctly (see Section 8.3.3).
With OFIDC = 0, the scalers input field ID is available as
output field ID on bit D6 of SAV and EAV, respectively on
pin IGP0 (IGP1), if FID output is selected.
2000 Mar 15
40
NXP [ NXP ]
