Samsung S5PC110, Manual

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S5PC110_UM 7 6BTVOUT & VIDEO DAC
7-14
7.7 WAVEFORM GENERATION AND CHROMA MODULATION (CVBS MODULE)
The CVBS sub-module combines the timing information and video data to generate the waveforms of ITU-R BT
470 TV signals. Two different data paths do this procedure, namely, one is for luminance data (Y) and the other is
for chrominance data (C). For the luminance data path, horizontal/ vertical synchronization pulses are formed and
merged to a properly scaled and offset luminance video data (Y). For the chrominance data paths, base band
chrominance data (Cb and Cr) are modulated with a sub-carrier FSC along with the video standard, that is:
C(n) = U(n) * sin(2 π FSC * n) + V(n) * cos(2 π FSC * n),
where U(n) and V(n) denote properly scaled and offset versions of Cb(n) and Cr(n), respectively. Then a pilot
sinusoidal waveform, called a burst, is formed and added prior to the start of modulated chrominance data C at
each line. At the end of CVBS sub-module data paths, the luminance data (Y) and the chrominance data (C) is
merged into one channel and form composite data (CVBS).
HVSYNC/VBI DATA
Y
CVBS
C
Burst
Y
CB
CR
DAC
Color
Space
Conversion
QAM
Figure 7-12 Data Flow of CVBS Sub-Module