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AD9889B video output is not stable

Question asked by zcliang on Apr 24, 2011
Latest reply on Apr 28, 2011 by DaveD

Hi,

I have post a question AD9889B video do not output on the HDMI interface

But I still have some questions about AD9889B, as I found that ad9889b video outputing is not stable.

1)Sometimes I boot my old board, then I found ad9889 do not output video.

But the reg 0x3d 0x3e value seems that ad9889b has detect the source.

[    0.358327] 0 : 0 0 0 0 0 0 0 0 0 0 1 e 3c 18 1 13
[    0.394077] 10 : 25 37 0 0 0 0 0 0 f 0 0 0 0 0 0 0
[    0.429960] 20 : 0 0 f 0 0 0 0 0 0 0 0 0 f 0 0 0
[    0.465991] 30 : 0 0 0 0 0 0 0 0 0 0 0 81 0 11 44 0
[    0.502019] 40 : 0 10 60 7e 78 88 4 80 0 0 0 0 0 0 0 0
[    0.537894] 50 : 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
[    0.573935] 60 : 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
[    0.609963] 70 : 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
[    0.646006] 80 : 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
[    0.682038] 90 : 0 0 0 0 0 0 e0 0 7 2 0 18 38 61 10 0
[    0.717918] a0 : 0 0 84 84 8 4 0 0 0 0 0 40 0 0 40 4
[    0.753948] b0 : a6 69 82 4d 67 4 2f 35 90 0 60 ff 0 0 0 0
[    0.789992] c0 : 0 0 0 0 0 0 4 0 1

2)When I use a 720p video source, I found that ad9889 would output a black screen for one second, about every 10 second.

The 720p video source is from the framebuffer output derectly.Its pixclock is 72.5MHz, slower than standard 74.5MHz.So the vclk is about 58Hz.

Is that affect?

 

Something I am not sure is that closing the pin ext_swg on my board have two crystal oscillator(one is 25MHz, another is 33Mhz).

 

zcliang

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