VP520S

1

VP520S

PAL/NTSC to CIF/QCIF Converter

Advance Information

Supersedes version in June 1995 Digital Video & DSP IC Handbook, HB3923-2

DS3504 - 3.2 October 1996

FEATURES

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Lower Power, pin compatible replacement for VP520

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Converts CCIR601 luminance and chrominance to CIF

or QCIF resolution, and vice versa, using a 27MHz

system clock.

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Luminance and chrominance channels have their own

sets of horizontal and vertical filters with on chip line

stores

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Each filter set may be configured to either decimate or

interpolate.

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NTSC line insertion or removal mode

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Produces / expects CIF/QCIF data in macroblock for-

mat.

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120 Pin QFP Package

Fig 1 : Simplified Block Diagram

DESCRIPTION

The VP520S is designed to convert 16 bit multiplexed

luminance and chrominance data between CCIR601 and CIF/

QCIF resolutions. Vertical and horizontal FIR filters are pro-

vided, with the vertical filters supported by on chip line stores.

The coefficients used by the filters are user definable, and are

down loaded from an independent host data bus. An internal

address generator supports an external DRAM frame store,

and also provides line to macroblock conversion.

When producing CIF or QCIF video the horizontal filters

precede the vertical filters, and are provided with between 8

and 16 taps. The vertical filters are provided with four CIF line

delays which allow a 5 tap filter to be implemented. When

producing QCIF the available RAM is used to provide six line

delays, which thus allows 7 tap filters to be used.

When the device is producing CCIR601 video, the incom-

ing data must be in macroblock format, and the vertical filters

precede the horizontal filters The inputs are firstly written to a

external CIF sized frame store, and are read out in line format.

The VP520S will support two complete frame stores, and

allows the CIF/QCIF data to be read out twice in order to

produce two interlaced fields of video.

The VP520S supports the conversion between CIF/QCIF

and NTSC video. An extra line is produced for every five lines

when producing CIF data, and one line in six is removed when

producing NTSC video. Poly phase filters are used to provide

the correct decimation and interpolation ratios.

ASSOCIATED PRODUCTS

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VP510 Colour Space Converter

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VP2611 H261 Encoder

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VP2615 H261 Decoder

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VP2612 Video Multiplexer

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VP2614 Video Demultiplexer

FRAME START

/ READY

16 BIT

FRAME STORE

BUS

RAM ADDRESS

GENERATOR

SUPPORTING

LINE TO BLOCK

CONVERSION

Horizontal

Filters

Vertical

Filters

FOUR

LINE

DELAYS

FILTER BLOCK

INPUT/

OUTPUT

FIFO

MUXING

FILTER BLOCK

FILTER BLOCK

VP520S

8 BIT

LUMINANCE

CREF

8 BIT

MACROBLOCK

BUS

COEFF

STORE

HOST

BUS

ADDRESS

CONTROL

SYNC

GENERATOR

HREF

VREF

MUX

8 BIT

CHROMINANCE

MACROBLOCK

STROBE

REQ BLKS

MUXING