SAA7109 PHILIPS [NXP Semiconductors], SAA7109 Datasheet - Page 72

• Manufacturer Part Number: SAA7109
• Description: PC-CODEC
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
9.3.1.3
As a reference for the output field processing, two signals
are available for the back-end hardware.
These signals are the input field ID from the scaler source
and a TOGGLE 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
is not synchronized to the input field detection, as it is only
dependent on the interpretation of this information by the
external hardware i.e. whether the output of the scaler is
processed correctly; see Section 9.3.3.
2004 Mar 16
PC-CODEC
Output field processing
72
When OFIDC = 0, the scalers input field ID is available as
output field ID on bit 6 of SAV and EAV, and respectively
on pin IGP0 (IGP1), if the FID output is selected.
When OFIDC[90H[6]] = 1, the TOGGLE information is
available as output field ID on bit 6 of SAV and EAV, and
respectively on pin IGP0 (IGP1) if the FID output is
selected.
Additionally bit 7 of SAV and EAV can be defined via
CONLH[90H[7]]. When CONLH[90H[7]] = 0 (default) it
sets bit 7 to logic 1; a logic 1 inverts the SAV/EAV bit 7.
So it is possible to mark the output of both tasks by
different SAV/EAV codes. This bit can also be seen as
‘task flag’ on the pins IGP0 (IGP1), if the TASK output is
selected.
SAA7108E; SAA7109E
Product specification