SAA7102_06 Datasheet, PDF (11/84 Pages) NXP Semiconductors – Digital video encoder

Philips Semiconductors
SAA7102; SAA7103
Digital video encoder
Table 8: Cursor modes
Cursor pattern
00
01
10
11
Cursor mode
CMODE = 0
second cursor color
first cursor color
transparent
inverted input
CMODE = 1
second cursor color
first cursor color
transparent
auxiliary cursor color
7.5 RGB Y-C_B-C_R matrix
RGB input signals to be encoded to PAL or NTSC are converted to the Y-C_B-C_R color
space in this block. The color difference signals are fed through low-pass filters and
formatted to a ITU-R BT.601 like 4 : 2 : 2 data stream for further processing.
The matrix and formatting blocks can be bypassed for Y-C_B-C_R graphics input.
When the auxiliary VGA mode is selected, the output of the cursor insertion block is
immediately directed to the triple DAC.
7.6 Horizontal scaler
The high quality horizontal scaler operates on the 4 : 2 : 2 data stream. Its control engines
compensate the color phase offset automatically.
The scaler starts processing after a programmable horizontal offset and continues with a
number of input pixels. Each input pixel is a programmable fraction of the current output
pixel (XINC/4096). A special case is XINC = 0, this sets the scaling factor to 1.
If the SAA7102; SAA7103 input data is in accordance with “ITU-R BT.656”, the scaler
enters another mode. In this event, XINC needs to be set to 2048 for a scaling factor of 1.
With higher values, upscaling will occur.
The phase resolution of the circuit is 12 bits, giving a maximum offset of 0.2 after 800
input pixels. Small FIFOs rearrange a 4 : 2 : 2 data stream at the scaler output.
7.7 Vertical scaler and anti-flicker filter
The functions scaling, Anti-Flicker Filter (AFF) and re-interlacing are implemented in the
vertical scaler.
Besides the entire input frame, it receives the first and last lines of the border to allow
anti-flicker filtering.
The circuit generates the interlaced output fields by scaling down the input frames with
different offsets for odd and even fields. Increasing the YSKIP setting reduces the
anti-flicker function. A YSKIP value of 4095 switches it off; see Table 91.
The programming is similar to the horizontal scaler. For the re-interlacing, the resolutions
of the offset registers are not sufficient, so the weighting factors for the first lines can also
be adjusted. YINC = 0 sets the scaling factor to 1; YIWGTO and YIWGTE must not be 0.
SAA7102_SAA7103_4
Product data sheet
Rev. 04 — 18 January 2006
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
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