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AD9889B output problem

Question asked by neky on Mar 13, 2012
Latest reply on Mar 20, 2012 by GuenterL

Please help me with AD9889B.

 

I work on my own PCB board with ADV7611, AD9889B and Xilinx FPGA between them.

My FPGA retransmit (as is) ADV7611 TTL signals to AD9889B and 2 TFT panels (1440x900).

 

HDMI reception works well, picture on the TFT screens is perfect with 25m HDMI cable

between the source and the board.

 

But I have problems with AD9889B. When I connect an external monitor (DELL) to HDMI output

the picture is almost good, but I have some glitches in dark zones and/or with specific patterns.

Now if I replace external monitor by the second board (AD9889B of the first board go to

ADV7611 receiver of the second one) the picture is very noisy, especially on the red channel,

even with a short cable.

 

I tried to change some registers (A2, A3) but no improvement.

 

There are my settings :

 

72 41 10 (50)  ; power up

72 0A 05 (41) ; bits 6:5 = 00 as recommended by AD , I2S audio, MCLK I2C 256xfs

72 98 07 (0B)  ; recommended by AD

72 9C 38 (5A) ; recommended by AD

72 9D 61 (60) ; bits 1:0 = 01 as recommended by AD

72 A2 87 (80) ; 87 = high speed

72 A3 87 (80) ; 87 = high speed

72 BB FF (00) ; recommended by AD

72 15 20 (00)  ; audio 48 KHz, 24 bits RGB > 30 MHz

72 16 30 (00)  ; 8 bit RGB

72 17 02 (00)  ; 16:9

72 18 06 (06)  ; disable CSC

72 01 00 (00)  ; Set 'N' value

72 02 18 (00)  ; Set 'N' value

72 03 00 (00)  ; Set 'N' value

72 0C 04 (3C) ; I2S[0] enable, standard I2S mode

 

What can be wrong ?

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