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Introduction
Final Rev F
Copyright 1996 by LSI Logic Corporation. All rights reserved.
erence. Internal post-processing lters interpolate decompressed images
with a horizontal size of less than 720 pixels so that they ll a complete
scan line at the operational clock frequency.
1.6.3.1 8-Bit CCIR 601 Interface
The CCIR 601 interface allows data to be time-division multiplexed onto
a single 8-bit interface—which supports easy connection to SMPTE
RP-125 type connectors. Eight-bit CCIR 601 is the preferred interface for
professional quality video equipment. It is also compatible with the Phil-
ips SAA7188 DENC chip and similar devices from Raytheon (TRW) and
Brooktree that can digitally modulate the signal to NTSC or PAL.
1.6.3.2 Post-Processing Filters
Decompressed images with fewer than 720 horizontal pixels, or selected
sections of images (such as the visible portion in pan and scan mode),
may be interpolated to occupy a full scan line using on-chip poly phase
interpolation lters. The lters are 64-tap oversampling lters and provide
up to eight output samples for every two input samples. The lter coef-
cients are xed as a windowed sync function. Sub-pixel accuracy of the
interpolator is 1/256th of a pixel. These lters are also used during sub-
pixel pan and scan to position the reconstructed output image to within
1/8 of a pixel.
1.6.3.3 Interlaced/Chroma Field Repeat or Chroma Line Repeat
Video Output
The L64005 can output video to an interlace-scanned video monitor or
television. The video timing circuitry must output the correct pulse train
for both odd and even elds, as well as the transition between elds. The
number of active scan lines in a typical eld is 240, though the actual
value is programmable.
In the interlaced/chroma line repeat output mode, the decoder outputs
each chroma line twice on neighboring lines in each eld.
1.6.3.4 Progressive/Field Repeat Video Output
The progressive/eld repeat video output mode is used in low resolution
modes when there are typically 240 lines in a luma frame. The luma data
is displayed twice, once in each eld time. The chroma data is displayed