Probelm in displaying image on monitor through nexys 4 ddr3

[jaggu.331]

Color of the image was changed. The original image was gray scale image but the displayed image resulted in the form of RGB components.Here,  I represented the data into 8 bits but the pins on the VGA was 12 pins. The problem is how to assign those 8  bits to 12 pins of VGA and how to view the original image on Monitor without any noise.

Obtained outputs are attached below.

Reply to solution.

[watari]

Hi @jaggu.331

I'm not familiar with nexy 4 ddr3.

However I might be able to help you.

> I represented the data into 8 bits but the pins on the VGA was 12 pins

I'm not sure. But if you use D-Sub 15 pin which has 3 non connection pin, it is analog RGB interface.

You have to implement DAC to output video signal to monitor.

Also, according to your picture, your timing controller is wrong.

Would you make sure video timing setting, too ?

Best regards, 

[jaggu.331]

Did you mean that we had generated Wrong timing signals for VGA controller?

How can I checkor change  my version settings?

[watari]

Hi @jaggu.331

According to the picture, it shows that VSYNC is 178Hz and HSYNC is 31.2KHz.

It's very strange.

Would you share your setting or a part of design about video controller ?

Best regards,

[jaggu.331]

I am sharing my VGA conroller  code for 256×256 pixel resolution image.

[watari]

Hi @jaggu.331

Sorry for my late reply.

I found this post today.

I mention to you about it.

If you wan to design similar antiq video game on Nexys 4, I recommend to learn PAL, SECAM or NTSC video timing.

Or, I recommend to follow latest video timing (ex. FHD@60p or FHD@30i as CEA video timing) and enclose black data as mask data.

ex.)

1920 x 1080

Horizontal :  0- 831 (Black) 832 - 1087 (Video data) 1088 - 1919 (Black)

Vertival : 0 - 411 (Black) 412 - 667 (Video data) 668 - 1079 (Black)

Also, I recommend to read @florentw 's video serieas. (https://forums.xilinx.com/t5/Video/Xilinx-Video-Series/td-p/849583)

It has principle and fandamental of video.

I strongly read them.

Would you try them ?

Best regards,