UG-707
ADV8005 Hardware Reference Manual
2.2.3.
Updither Configuration
The updither block on each of the input channels can be used to increase the bit width of the incoming video. This is useful if the output video
must be a certain bit depth and the input video is below this level. Updither can increase color richness and reduce the effects of quantization,
rounding and truncation which may have been induced on the video data. The updither block can be used in a situation where the video input
to the
is in 8-bit form and must be converted to 10-bit or 12-bit for output.
The operation of the updither block can be seen in
. When converting to a higher bit width, the
updither block first converts
to a bit width of 14 and then down converts to 12- and 10-bit width.
Figure 35: Updither Operation
is used to configure the updither algorithm level. This should be configured depending on the input and output from the
block. For example, if the input video is 8-bit data and the output is 12-bit data, this should be set to the highest level.
updither_level[1:0]
, IO Map,
Address 0x1A0D[5:4]
This signal is used to set the sharpness of the updither block's HPF processing of the video data. When this signal is set to low the
characteristic of the dither block's HPF gives smoother output video. When this signal is set to high, the characteristic of the dither block's
HPF gives sharper output video.
Function
updither_level[1:0]
Description
00
Low updither
11
High updither
2.2.4.
Clock Configuration
This section describes the method of configuring the various clocks of the
. These controls can be employed to automatically configure the internal clocks for the following:
•
Pixel de-repetition/front-end formatter clock configuration (main and secondary TTL channels and Serial Video Rx channel)
•
Timing generation for inputs with AV-codes (main and secondary TTL channels only)
•
ACE configuration (main TTL channel only)
•
VBI ancillary data (main TTL channel only)
In any of these modes, the
controls must be configured.
8-bit video source
12-bit video output
10-bit video output
8 to 14 bit
up dithering
14 to 12 bit
down dithering
12 to 10 bit
down dithering
8-bit video source
12-bit video output
10-bit video output
8 to 14 bit
up dithering
14 to 12 bit
down dithering
12 to 10 bit
down dithering
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