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
VP520S
FEATURES
s
s
Lower Power, pin compatible replacement for VP520
Converts CCIR601 luminance and chrominance to CIF
or QCIF resolution, and vice versa, using a 27MHz
system clock.
Luminance and chrominance channels have their own
sets of horizontal and vertical filters with on chip line
stores
Each filter set may be configured to either decimate or
interpolate.
NTSC line insertion or removal mode
Produces / expects CIF/QCIF data in macroblock for-
mat.
120 Pin QFP Package
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.
s
s
s
s
s
ASSOCIATED PRODUCTS
s
s
s
s
s
VP510 Colour Space Converter
VP2611 H261 Encoder
VP2615 H261 Decoder
VP2612 Video Multiplexer
VP2614 Video Demultiplexer
FILTER BLOCK
HOST
BUS
COEFF
STORE
Horizontal
Filters
VP520S
MACROBLOCK
STROBE
REQ BLKS
8 BIT
LUMINANCE
FOUR
LINE
DELAYS
INPUT/
OUTPUT
FIFO
Vertical
Filters
8 BIT
MACROBLOCK
BUS
MUX
16 BIT
FRAME STORE
BUS
FRAME START
/ READY
RAM ADDRESS
GENERATOR
SUPPORTING
LINE TO BLOCK
CONVERSION
ADDRESS
8 BIT
CHROMINANCE
MUXING
MUXING
CREF
FILTER BLOCK
CONTROL
FILTER BLOCK
SYNC
GENERATOR
HREF
VREF
Fig 1 : Simplified Block Diagram
1
MITEL [ MITEL NETWORKS CORPORATION ]
