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1 Introduction
The TVP5146 device is a high quality, single-chip digital video decoder that digitizes and decodes all popular
baseband analog video formats into digital component video. The TVP5146 decoder supports the analog-to-digital
(A/D) conversion of component RGB and YPbPr signals, as well as the A/D conversion and decoding of NTSC, PAL,
and SECAM composite and S-video into component YCbCr. This decoder includes four 10-bit 30-MSPS A/D
converters (ADCs). Preceding each ADC in the device, the corresponding analog channel contains an analog circuit
that clamps the input to a reference voltage and applies a programmable gain and offset. A total of 10 video input
terminals can be configured to a combination of RGB, YPbPr, CVBS, or S-video video inputs.
Component, composite, or S-video signals are sampled at 2
× the square-pixel or ITU-R BT.601 clock frequency,
line-locked, and are then decimated to the 1
× pixel rate. CVBS decoding utilizes five-line adaptive comb filtering for
both the luma and chroma data paths to reduce both cross-luma and cross-chroma artifacts. A chroma trap filter is
also available. On CVBS and S-video inputs, the user can control video characteristics such as contrast, brightness,
saturation, and hue via an I2C host port interface. Furthermore, luma peaking (sharpness) with programmable gain
is included, as well as a patented chroma transient improvement (CTI) circuit.
A built-in color space converter is applied to decoded component RGB data.
The following output formats can be selected: 20-bit 4:2:2 YCbCr or 10-bit 4:2:2 YCbCr.
The TVP5146 decoder generates synchronization, blanking, field, active video window, horizontal and vertical syncs,
clock, genlock (for downstream video encoder synchronization), host CPU interrupt and programmable logic I/O
signals, in addition to digital video outputs.
The TVP5146 decoder includes methods for advanced vertical blanking interval (VBI) data retrieval. The VBI data
processor (VDP) slices, parses, and performs error checking on teletext, closed caption (CC), and other VBI data.
A built-in FIFO stores up to 11 lines of teletext data, and with proper host port synchronization, full-screen teletext
retrieval is possible. The TVP5146 decoder can pass through the output formatter 2
× the sampled raw luma data for
host-based VBI processing.
The decoder provides the option for concurrent processing of pixel-locked CVBS and RGB/YPbPr input formats.
The main blocks of the TVP5146 decoder include:
Robust sync detection for weak and noisy signals as well as VCR trick modes
Y/C separation by 2-D, 5-line, adaptive comb or chroma trap filter
Fast-switch input for pixel-by-pixel switching between CVBS and YPbPr/RGB component video inputs
(SCART support)
Four 10-bit, 30-MSPS A/D converters with analog preprocessors [clamp and automatic gain control (AGC)]
Luminance processor
Chrominance processor
Component processor
Clock/timing processor and power-down control
Software-controlled power-saving standby mode
Output formatter
I2C host port interface
VBI data processor