saa7114 NXP Semiconductors, saa7114 Datasheet - Page 24

• Manufacturer Part Number: saa7114
• Description: Pal/ntsc/secam Video Decoder With Adaptive Pal/ntsc Combfilter, Vbi-data Slicer And High Performance Scaler
• Manufacturer: NXP Semiconductors

Philips Semiconductors
SAA7114_3
Product data sheet
8.1.3.2 Luminance path
The rejection of the chrominance components within the 9-bit CVBS or Y input signal is
achieved by subtracting the remodulated chrominance signal from the CVBS input.
The comb filtered C
block. Its characteristic is controlled by LUBW (subaddress 09h, bit D4) to modify the
width of the chrominance ‘notch’ without influencing the chrominance path. The
programmable frequency characteristics available, in conjunction with the LCBW2 to
LCBW0 settings, can be seen in
frequency curves are only valid for Y-comb disabled filter mode (YCOMB = 0). In comb
filter mode the frequency response is flat. The center frequency of the notch is
automatically adapted to the chosen color standard.
The interpolated C
from the subcarrier generation block 2. This second DTO is locked to the first subcarrier
generator by an increment delay circuit matched to the processing delay, which is different
for PAL and NTSC standards according to the chosen comb filter algorithm. The two
modulated signals are finally added to build the remodulated chrominance signal.
The frequency characteristic of the separated luminance signal can be further modified by
the succeeding luminance filter block. It can be configured as peaking (resolution
enhancement) or low-pass block by LUFI3 to LUFI0 (subaddress 09h, bits D3 to D0). The
16 resulting frequency characteristics can be seen in
settings can be used as a user programmable sharpness control.
The luminance filter block also contains the adjustable Y-delay part; programmable by
YDEL2 to YDEL0 (subaddress 11h, bits D2 to D0).
B
B
-C
-C
Rev. 03 — 17 January 2006
R
R
samples are multiplied by two time-multiplexed subcarrier signals
components are interpolated (upsampled) by the low-pass 3
Figure 13
to
Figure
16. It should be noted that these
Figure
PAL/NTSC/SECAM video decoder
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
17. The LUFI3 to LUFI0
SAA7114
24 of 144