Hyundai HPT-4205, Руководство по обслуживанию

Страница: 28 / 65

26
Plasma TV Service Manual 14/03/2005
GND
pins provide power to the clock PLL and help the user design for optimal
performance. The designer should provide quiet, noise-free power to these pins.
Ground
The ground return for all circuitry on-chip. It is recommended that the AD9883A be
assembled on a single solid ground plane, with careful attention given to ground
current paths.
12.22. SAA7118E
12.22.1. General Description
The SAA7118E is a video capture device for applications at the image port of VGA controllers. Philips
X-VIP is a new multistandard comb filter video decoder chip with additional component processing,
providing high quality, optionally scaled, video.
The SAA7118E is a combination of a four-channel analog preprocessing circuit including source
selection, anti-aliasing filter and ADC, an automatic clamp and gain control, a Clock Generation Circuit
(CGC), a digital multistandard decoder containing two-dimensional chrominance/luminance separation
by an adaptive comb filter and a high performance scaler, including variable horizontal and vertical up
and downscaling and a brightness, contrast and saturation control circuit.
It is a highly integrated circuit for desktop video and similar applications. The decoder is based on the
principle of line-locked clock decoding and is able to decode the colour of PAL, SECAM and NTSC
signals into ITU 601 compatible colour component values. The SAA7118E accepts CVBS or S-video
(Y/C) as analog inputs from TV or VCR sources, including weak and distorted signals as well as
baseband component signals Y-P
B
-P
R
or RGB. An expansion port (X-port) for digital video
(bidirectional half duplex, D1 compatible) is also supported to connect to MPEG or video phone codec.
At the so called image port (I-port) the SAA7118E supports 8 or 16-bit wide output data with auxiliary
reference data for interfacing to VGA controllers.
The target application for the SAA7118E is to capture and scale video images, to be provided as digital
video stream through the image port of a VGA controller, for capture to system memory, or just to
provide digital baseband video to any picture improvement processing.
12.22.2. Features
Video acquisition/clock
• Up to sixteen analog CVBS, split as desired (all of the CVBS inputs optionally can be used to convert
e.g. Vestigial Side Band (VSB) signals)
• Up to eight analog Y + C inputs, split as desired
• Up to four analog component inputs, with embedded or separate sync, split as desired
• Four on-chip anti-aliasing filters in front of the Analog-to-Digital Converters (ADCs)
• Automatic Clamp Control (ACC) for CVBS, Y and C (or VSB) and component signals
• Switchable white peak control
• Four 9-bit low noise CMOS ADCs running at twice the oversampling rate (27 MHz)
• Fully programmable static gain or Automatic Gain Control (AGC), matching to the particular signal
properties
• On-chip line-locked clock generation in accordance with “ ITU 601 ”
• Requires only one crystal (32.11 or 24.576 MHz) for all standards
• Horizontal and vertical sync detection.
Video decoder
• Digital PLL for synchronization and clock generation from all standards and non-standard video
sources e.g. consumer grade VTR
• Automatic detection of any supported colour standard
• Luminance and chrominance signal processing for PAL B, G, D, H, I and N, combination PAL N, PAL
M, NTSC M, NTSC-Japan, NTSC 4.43 and SECAM
• Adaptive 2/4-line comb filter for two dimensional chrominance/luminance separation, also with VTR
signals
– Increased luminance and chrominance bandwidth for all PAL and NTSC standards
– Reduced cross colour and cross luminance artifacts
• PAL delay line for correcting PAL phase errors
• Brightness Contrast Saturation (BCS) adjustment, separately for composite and baseband signals