pnx1500 NXP Semiconductors, pnx1500 Datasheet - Page 373

• Manufacturer Part Number: pnx1500
• Description: Pnx15xx Series Connected Media Processor
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Volume 1 of 1
PNX15XX_SER_3
Product data sheet
2.7.1 Supported Output Formats
2.7.2 Layer Selection
2.7.3 Chrominance Downsampling (CDNS)
2.7.4 Gamma Correction and Noise Shaping (GNSH& ONSH)
Besides two instances of the formatter, the output-interface unit also contains two
instances of a chroma-downsampling unit (CDNS), one instance of a gamma-
correction and noise-shaping unit (GNSH) and several input-output muxes; the
gamma-lookup-table allows possible gamma-correction on the final composited
image stream, whereas the noise shaper logic reduces (dithers) the number of bits
per pixel (in the gamma-corrected image) via error propagation. The insertion of VBI
data into the D1 or D1-like output streams is also supported. In order to support 4:2:2
output formats, two chroma-down-sample filters (CDNS) are included at the
beginning of the input-data chain. The input multiplexer (IMUX) is used to
appropriately select the input stream depending on the partitioned layer boundary.
The interleaving unit (INTL) is to be programmed in a pass-through mode.
The output formatter supports the following output formats:
Remark: The PNX15xx Series digital video interface has assigned up to 30 data pins
to the video output interface. Refer to
different pin assignment.
In the Mixers, the final image (to be displayed) is composed (composited) from the
images obtained from the various layers.
Chroma down-sampling is necessary for creating a YUV 4:2:2 output signal. It uses a
(1,2,1)/4 low-pass filter to create co-sited U&V samples (because ITU-R.601
specifies only co-sited sub-sampling). Every second U&V output sample is discarded,
but then the other sample is repeated. Consequently, the output stream is still 4:4:4
and the repeated samples have to be discarded later.
The gamma-lookup-table allows possible gamma-correction on the final composited
image stream, whereas the noise shaper logic reduces (dithers) the number of bits
per pixel (in the gamma-corrected image) via error propagation.
In the GNSH unit, the QVCP-internal data format is converted into the desired output
format. The overshoots and undershoots which are generated by the QVCP layer
units are also removed if noise shaping is off and the desired output is not the 9+1
mode; the data will be left-shifted by one bit and the MSB bit will be lost.
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30-, 24- or 18-bit parallel YUV or RGB + external H- and V-sync and composite
blank
10- or 8-bit D1 or D1-like 4:2:2 YUV
10- or 8-bit D1-like 4:4:4 YUV/RGB
20- or 16-bit double-interface semi-planar 4:2:2 D1 mode with 10- or 8-bit Y and
10- or 8-bit U/V multiplexed data
Rev. 3 — 17 March 2006
Chapter 3 System On Chip Resources
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
PNX15xx Series
Chapter 11: QVCP
for the
11-20