Datasheet

Copy
Protection
Detector
VBI Data
Processor
Output
Formatter
Composite
Processor
CVBS/Y
C
YCbCr
Y[9:0]
Timing
Processor
AVID
FID
GLCO
XTAL1
XTAL2
RESETB
Component
Processor
CH1 A/D
CH2 A/D
CH3 A/D
Pr/R
Pb/B
Y/G
YCbCr
FSS
HS/CS
VS/VBLK
DATACLK
C[9:0]
CH4 A/D
CVBS/Y/G
Host
Interface
SCL
SDA
Slice VBI Data
2
Decimation
PWDN
2
Decimation
2
Decimation
2
Decimation
TVP5146M2
SLES141H –JULY 2005– REVISED FEBRUARY 2012 www.ti.com
programmed to two formats: 20-bit 4:2:2 with external syncs or 10-bit 4:2:2 with embedded/separate
syncs. The circuit detects pseudosync pulses, AGC pulses, and color striping in Macrovision-encoded
copy-protected material. Information present in the VBI interval can be retrieved and either inserted in the
ITU-R BT.656 output as ancillary data or stored in internal FIFO and/or registers for retrieval via the host
port interface.
Figure 2-2. Digital Video Processing Block Diagram
2.2.1 2x Decimation Filter
All input signals are oversampled by a factor of two (27 MHz). The A/D outputs first pass through
decimation filters that reduce the data rate to 1× the pixel rate. The decimation filter is a half-band filter.
Oversampling and decimation filtering can effectively increase the overall signal-to-noise ratio by 3 dB.
2.2.2 Composite Processor
Figure 2-3 is a block diagram of the TVP5146M2 digital composite video processing circuit. This circuit
receives a digitized composite or S-Video signal from the ADCs and performs Y/C separation (bypassed
for S-Video input), chroma demodulation for PAL/NTSC and SECAM, and YUV signal enhancements.
The 10-bit composite video is multiplied by the subcarrier signals in the quadrature demodulator to
generate color difference signals U and V. The U and V signals are then sent to low-pass filters to achieve
the desired bandwidth. An adaptive 5-line comb filter separates UV from Y based on the unique property
of color phase shifts from line to line. The chroma is remodulated through a quadrature modulator and
subtracted from line-delayed composite video to generate luma. This form of Y/C separation is completely
complementary, thus there is no loss of information. However, in some applications, it is desirable to limit
the U/V bandwidth to avoid crosstalk. In that case, notch filters can be turned on. To accommodate some
viewing preferences, a peaking filter is also available in the luma path. Contrast, brightness, sharpness,
hue, and saturation controls are programmable through the host port.
18 Functional Description Copyright © 2005–2012, Texas Instruments Incorporated
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