The ADV7611 board is used with DVI input and DVI output. It seems that the color depth is reduced, trying with RGB signals and grey wedge. Output does not corresponded input, looks like 5bpc.
Any hint what to look for?
Best regards, Bernd
What script are you using and video format?
We have just updated our recommended register settings document for the ADV7611. Section 2.1 has been updated to make the ADV7611 more robust to poor DVI sources. Our new recommendation is to set HDMI MAP register 0x6F to the value 0x08.
Link to recommended register settings document for the ADV7611:
Hopefully this should answer your question.
we are using the eval board "as is".
The ARM processor boots as:
ADI HDMI Repeater Application Ver R1.55.2
PLATFORM: ATV 7611/2 EVAL Rev 0x0
HDMI-RX: ADV7611 Rev 0x2051
HDMI-TX: ADV7511 Rev 0x12
Created: Jun 11 2012 At 11:16:23
The video formats appears to be irrelevant, we tried 1920x1200/60Hz CVT-RB, 1680x1050/60Hz CVT, 1280x1024/60Hz DMT and some others.
It is not simply a reduced color depth we are seeing here although that was the first impression.
On closer inspection it seems that bright colors (above 220 at 8bpc) are compressed near saturation (or already saturating), while everything darker shows distinctive steps.
Checking the updated recommended register settings rev. 1.4 and 1.5, both updates already are at the new recommended values:
HDMI MAP 6F = 0x08
HDMI MAP 9B = 0x03
It's difficult to know if this is a hardware or software issue. Here is what I would do in an effort to understand the problem further.
1. Apply a Green ramp test pattern to the ADV7611 - do you see steps on the ramp output?
2. Apply a Red ramp test pattern to the ADV7611 - do you see steps on the ramp output?
3. Apply a Blue ramp test pattern to the ADV7611 - do you see steps on the ramp output?
This should tell us if there is an issue on just one of the R-G-B signal paths or if the issue is on all of the outputs.
What value is written to register 0x02 in the IO map? I believe this register have the following value: 1111 001X
If you are still having an issue, could you disable the SW driver, and run the following script:
6-1f Port A, 1080p Any Color Space In (YCrCb 444 24bit from ADV761x) Through HDMI Out 444 YCrCb VIC[16,31,32]
The color space from the ADV7511 will probably be wrong but can be corrected with the following write:
72 55 00 ; Set RGB 444 in AVinfo Frame
You will also need to the following write in the ADV7611:
98 02 F2 ;
This script will output HDMI instead of DVI. The PCB evaluation note and scripts can be downloaded from:
Sorry to come back this late but I have been unavailable for a while.
I have applied a test image with all four -- gray ramp, red ramp, green ramp and blue ramp.
There are discernable steps in all ramps although these are the most distinctive in the gray ramp -- but I believe this to be obvious.
Maybe interesting is that the steps in red, green and blue do not occur at exactly (but still roughly) the same values. This is also recognizable in slightly tinted step boundaries in the gray ramp.
Register 0x02 in the IO map contains 0xF2 (1111 0010) as you expected.
I had some trouble running the script but otherwise found out something interesting.
Bits 7-4 of IO 0x02 contains INP_COLOR_SPACE. A value of 1111xxxx (see above) is supposed to mean "AUTO" (default).
Sounds great, but: When changing this to 0001b ("Force RGB 0-255") (register IO 0x02 now contains 0x12) the gray ramp looks pretty smooth and at least close to 1:1.
While this would at least improve DVI operation I do not understand why this should have this much of an effect (or in fact any). Also forcing this removes the automatic detection and handling of other color formats, which would be a disadvantage.
I am guessing that there has to be some other place to achieve correct color representation while still sticking to "AUTO" mode in IO 0x02.
I have attached a full register dump of ADV7611 after booting up the evaluation board and connecting a DVI video source at 1920x1200/60Hz.
The file also contains the log report from connecting the video source.
What is the the best configuration for ADV7611 to achieve true and exact color reproduction?
For the auto color detection, this register 0x02 uses the AVI info-frame to determine the incoming color space. Of course for DVI mode, there are no AVI info-frames so it is not correct to set these bits to auto mode. Your firmware should set these bits to 1B when DVI mode is detected I think.
I was (maybe mistakenly) under the impression that DVI vs. HDMI would mostly be taken care of by ADV7611 itself and the evaluation board software. Well, perhaps not.
Detecting DVI mode or HDMI mode is done in register HDMI 0x05 bit 7, right?
For clarification: What value do you propose to write into IO 0x02? You seem to suggest 0x1B when I would suppose 0x12.
Which other registers need to be initialized differently in DVI mode?
I have found no recommendations for DVI mode, is there a document describing this?
If you are using the software driver to configure the ADV7611/ADV7511, i.e.
DVI vs HDMI should be taken of.
If you are using the scripts to configure the ADV7611/ADV7511, you will probably need to change some things for DVI.
Which one are you using?
I am using the software driver in the exact version you quote. No script at all.
This is the starting point for my observation and the resulting query. This means that I am consistently seeing the modified color ramps without any interference through USB or RS232, the software driver is running.
The register dumps in the last post were taken over RS232 without changing any setting.
You both appear to agree in one point: that software outside ADV7611 needs to take care of some differences in DVI and HDMI mode. Do I read that right?
If that is indeed the case, then the software driver seems to miss something, hence the color steps, right?
Which still leaves the question, which registers have to be modified depending on DVI or HDMI mode?
I am still hoping that all this is already written down somewhere and I simply missed it.
In any case thank you very much for your time and help.
Yes, there are some differences in register settings between DVI and HDMI. The software driver you have should take care of these automatically. The configuration scripts will not.
Can you post some screen shots of what you are seeing?
Also, what are you using as source and what are you using as sink?
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