VT1621M VIA, VT1621M Datasheet - Page 18

• Manufacturer Part Number: VT1621M
• Description: TV Encoder
• Manufacturer: VIA

PD[11:0]
Architecture Description
Data Capture
The 8-bit or 12-bit multiplexed input data is captured by this
module and is transferred to 24-bit data for one pixel.
Color Space Converter
The data from the Data Capture module is RGB or YCrCb
format.
format.
Scaler and Deflicker
This module converts the lines of input pixel data to the
appropriate number of output lines for producing a full-screen
image on the television receiver. The image can be scaled to
100% within the viewable area of the screen. The device can
perform vertical filtering to reduce the effects of picture flicker
due to the interlacing of the output image.
process trades off vertical resolution in order to reduce flicker,
the amount of flicker filtering is programmable and allows the
process to be optimized for the specific image. This module
finally generates the YUV444 pixel data of the interlaced
image to the encoder module.
Revision 1.0 June 17, 2002
SBD
SBC
This module converts both formats to YUV 422
We Connect
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Capture
Interface
Serial
Data
Bus
HSYNC VSYNC
Converter
Vertical Timing
Horizontal &
F
Space
Color
UNCTIONAL
CRTC
Because this
Deflicker
Scaler
and
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D
XCLK P_OUT
Encoder
This module accepts the YUV444 pixel data and converts it to
a standard baseband television signal that is compatible with
worldwide standards including PAL (B, D, G, H, I, N, Nc, M)
and NTSC (M, J). The Y data can be manipulated for contrast
control and a setup level can be added for brightness control.
The U, V data can be scaled to achieve color saturation
control.
appropriate subcarrier sine/cosine waveforms and a phase
offset may be added onto the color subcarrier during active
video to allow hue adjustment. The resulting U and V signals
are added together to make up the chrominance signal. The
luma (Y) and chroma signals are added together to make up
the composite video signal.
signals make up the S-video signal.
DAC
Both VT1621 and VT1621M contain three DACs. Each DAC
is used to convert digital composite or luma / chroma data to
analog signals and can be individually powered off if not
required. The DAC module also has an auto-detection circuit,
which provides a way to sense the connection of a TV to either
S-video or composite Video outputs.
ESCRIPTION
Clock
PLL
Pixel
Besides, U, V signals are modulated by the
Encoder
NTSC/
PAL
VT1621 / VT1621M TV Encoder
Separated luma and chroma
DAC
Funcitonal Descriptions
Y / R
C / G
CVBS / B