pnx8510 NXP Semiconductors, pnx8510 Datasheet - Page 19

• Manufacturer Part Number: pnx8510
• Description: Analog Companion Chip
• Manufacturer: NXP Semiconductors

Philips Semiconductors
9397 750 12612
Product data
7.1.9 Luminance and Chrominance Processing
Programming flexibility includes NTSC-M, PAL-B, SECAM main standards as well as
other variations. A number of possibilities are provided for setting different video
parameters, such as:
The sync generator generates all the signals required to control the signal
processing, provide the composite sync signal, insert the color burst, etc.
The encoder includes a cross-color reduction filter to reduce cross talk between the
luminance and chrominance channels. In the CVBS signal, the signal amplitude is
reduced by 15/16 to avoid overflow.
The Y processing provides a high performance 5 MHz lowpass filter. It adjusts the
level range according to the standard and inserts the sync and blanking pulses. The
insertion stage generates the correct pulse shapes. No further processing is
necessary of the D/A converters for this purpose.
Chroma processing operates on the baseband signals as long as possible. At first,
the signal amplitudes are adjusted and the burst is inserted. Afterwards the signals
are passed through a 1.4 MHz lowpass filter. This filter can be switched to a higher
cut-off frequency to allow more chroma bandwidth with S-Video. The quadrature
modulator uses a DTO (Discrete Time Oscillator) with 32-bit resolution for the
subcarrier generation. Even with this high resolution, the DTO cannot generate the
carrier locked to the line frequency as the standards require without further means.
So the sync generator is able to reset the DTO periodically. This feature is controlled
by the PHRES programming bits. These modes may only be switched on if the
encoder is programmed to generate a standard signal; they will not work in
non-interlaced mode.
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Black and blanking level control
Color subcarrier frequency
Variable burst amplitude
Rev. 04 – 12 January 2004
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
PNX8510/11
Analog companion chip
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