Circuit Descriptions, List of Abbreviations, and IC Data Sheets
EN 89L04L AA 9.
9.6.3 Audio Source Selection
The signals coming out of the DEMDEC (internal demodulator/
decoder block of the Hercules) are selectable and consist of
the following (depending on the transmission):
• DEC L/R (Can be NICAM, FM 2CS, or BTSC Stereo).
• Mono (Refers to fallback/forced Mono in Stereo
Transmission).
• SAP.
For L04, the assigned I/O with respect to the Hercules is as
follows:
• SCART1 or AV1 Input assigned to Audio In 5.
• SCART2 or AV2 Input assigned to Audio In 3.
• Side AV Input assigned to Audio In 4.
• External Interface Input assigned to Audio In 2.
• SCART1 Output (EU) assigned to SCART Output.
• SCART2 Output (EU) or Monitor Output (LA/NA/AP)
assigned to Headphone Output.
• Constant Level Output assigned to Loudspeaker Output.
9.6.4 Video Source Selection
Video source selection is done inside the Hercules. Therefore
it provides a video switch with 3 external CVBS inputs and a
CVBS output. All CVBS inputs can be used as Y-input for Y/C
signals. However, only 2 Y/C sources can be selected because
the circuit has 2 chroma inputs.
All input signals are converted to YUV, and looped through an
external interface. This to enable picture improvement features
(like LTI/CTI) or PIP.
9.7 Video Processing
The Video Processor is basically the Hercules and the
TDA9178 (CTI/LTI). Video processing is done in these two
chips such as the Brightness Control, Contrast Control and so
on.
Some features:
• Full YUV-loop interface (alternative functions: DVD, RGB
or Y/C).
• Internal OSD insertion (not Saturation or Contrast
controlled).
• Double window implementation.
• Linear / non linear scaling for 16:9 sets.
• Tint (hue) on UV signals (including DVD).
• Peaking, Coring, Black \ Blue \ White-stretch.
• Transfer-Ratio and Scavem (also on TXT).
9.7.1 Features
The features included in the Hercules are as follows:
• Brightness Control.
• Contrast Control.
• Saturation Control.
• Sharpness Control.
• Peak White Limiter.
• Beam Current Limiter.
• Black Stretch (Contrast Plus).
For sets with the TDA9178, there are two extra features:
• Luminance Transient Improvement (LTI).
• Color Transient Improvement (CTI).
9.7.2 Block Diagram
Following diagram is the block diagram of the video processing
part:
Figure 9-5 Video processing block diagram
9.7.3 LTI/CTI
The TDA9178 is an I2C-bus controlled IC (INCREDIBLE chip)
with YUV interface. This IC can do mainly histogram
processing, color transient improvement (CTI) and line
transient improvement (LTI).
• Luminance Vector Processing involves histogram function,
which provides scene dependent contrast improvement,
adaptive black and white point stretching.
• Color Vector Processing involves skin tone correction,
green enhancement and blue stretch.
• Spectral Processor involves step improvement processing,
contour processing, smart sharpness control, color
dependant sharpness and Color Transient Improvement.
• Noise detector, feature mode detector and cue flash
functions.
• Demonstration mode shows all the improvement features
in one picture.
Table 9-12 Pinning overview TDA9178
Pin Symbol Description
1 SC Sandcastle input pin
2 n.c. Not connected pin
3 ADEXT1 External AD-conversion #1 input pin
4 ADEXT2 External AD-conversion #2 input pin
5 ADEXT3 External AD-conversion #3 input pin
6 Y in Luminance input pin
7 ADR Address selection input pin
8 U in -(B-Y) signal input pin
9 V in -(R-Y) signal input pin
10 TP Testpin, connected to ground
11 SCL I2C-bus: clock input pin
12 n.c. Not connected pin
13 n.c. Not connected pin
14 SDA I2C-bus: data input pin
15 DECDIG Decoupling digital supply
16 V out -(R-Y) signal output pin
17 U out -(B-Y) signal output pin
18 V ee Ground pin
19 Y out Luminance output pin
20 V cc Supply-voltage pin
21 S out Luminance output for SCAVEM
22 CF Cue-flash output pin
23 n.c. Not connected pin
24 n.c. Not connected pin
TUNER
SAW
95,94,80,79,
AUDIO
AMP
68,69
VIDEO
AUDIO
SAW
NVM
MONITOR
OUT
2021
CRT
LTI/CTI
78,77,76,75,
74,73,72,71,70
6586,81,
67,66
HERCULES
SW
2425
29,30
PIP/
DVD
CVBS/AUDIO
REAR/SIDE
INPUT/OUTPUT
INPUT
RGB/CVI
42,4344
53,54,55
57,5859
49,50,51
E_14480_071.eps
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