Pass Through Mode - Analog Devices Advantiv ADV7619 Hardware User's Manual

Hardware User Guide
UP_CONVERSION_MODE , Addr 68 (HDMI), Address 0x1D[5]
A control to select linear or interpolated 4:2:2 to 4:4:4 conversion. A 4:2:2 incoming stream is upconverted to a 4:4:4 stream before being
sent to the CP.
Function
UP_CONVERSION_MODE
0 (default)
1
Notes
When the ADV7619 pixel output format is set to 4:2:2 (refer to the Pixel Port Output Modes section), the DPP section down converts the
4:4:4 stream from the HDMI section according to DS_WITHOUT_FILTER .
•
For a 4:4:4 HDMI input stream to the ADV7619
•
The DPP section filters and downsamples the video data from 4:4:4 to 4:2:2 format if DS_WITHOUT_FILTER is set to 0. The
DPP section only downsamples, without filtering, the video data from the HDMI section if DS_WITHOUT_FILTER is set to 1.
•
For a 4:2:2 HDMI input stream, the functionality of DS_WITHOUT_FILTER is reversed.
•
This inversion ensures that for a 4:2:2 HDMI input stream no filtering will be applied if DS_WITHOUT_FILTER is left to its
default value 0. When a 4:2:2 HDMI input stream is input to the ADV7619, the DPP section downsamples, without filtering, the
video data from 4:4:4 to 4:2:2 format if DS_WITHOUT_FILTER is set to 0. If DS_WITHOUT_FILTER is set to 1, the DPP
filters and downsamples the video data from 4:4:4 to 4:2:2 format.
DS_WITHOUT_FILTER , Addr 40 (IO), Address 0xE0[7]
Disables the chroma filters on Channel B and Channel C while keeping the downsampler functional.
Function
DS_WITHOUT_FILTER
0 (default)
1

PASS THROUGH MODE

The ADV7619 can process streams up to 3 Gbps only in the case where the CP core is fully bypassed. This is the mandatory mode for
frequencies above 2.25 Gbps and must be set by setting CP_COMPLETE_BYPASS_IN_HDMI_MODE .
ADV7619 offers also pass through modes for frequencies below 2.25GBps. It can pass through the video data of an HDMI stream with no
formatting. The video is passed from the HDMI section through the DPP and CP cores, out through the pixel output formatter without
filtering or alteration. This can be achieved with the following settings:
4:2:2 Pass Through
•
Set DPP_BYPASS_EN to 1 to use the CP CSC
•
Set UP_CONVERSION_MODE to 0
•
Set DS_WITHOUT_FILTER to 0
•
Configure the pixel output formatter to output a 4:2:2 stream (refer to the Pixel Port Output Modes section)
4:4:4 Pass Through
•
Set UP_CONVERSION_MODE to 0 or to 1
•
Set DS_WITHOUT_FILTER to 0 or to 1
•
Configure the pixel output formatter to output a 4:4:4 stream (refer to the Pixel Port Output Modes section)
COMPONENT
CHANNEL
Y
Cb/Cr
Description
Cr and Cb samples are repeated in their respective channel
Interpolate Cr and Cb values
Description
Filters and downsamples
Downsamples only (no filtering)
Y /Cb Y
0 0
Y
BITS[12:0]
0
BITS[12:0]
Cb
0
Figure 31. Video Data Output by DPP in 4:2:2 Pass Through Mode
/Cr Y /Cb Y
0 0 0 2 0
Y Y
1 2
Cr Cb Cr
0 2
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...
/Cr Y /Cb
2 0 4
...
Y Y
3 4
...
Cb
2 4
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