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Altera_Forum's avatar
Altera_Forum
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13 years ago

"VGA display" problem on DE2 board - Only 1 color on screen :(

Hi everyone,

My project is to display an image 640x480 (from SDRAM) on a monitor. I write the hardware by my own in Verilog.

The structure of my design : SDRAM <-- DMA-50MHz ( Master read + slave control ) <---->50Mhz- asynchronous FIFO - 25Mhz <---> 16_to_30_converter (25Mhz).

Beside that. there are also modules that create Hsync, Vsync, HBlank, etc...

Everythings is ok except for one thing :

- when i try to display the image, the monitor display only 1 color (maybe blue or red, just one color only).

- Then I try to catch the output signal ( pixel color R,G,B and Hsyn,Vsyn,etc..) on SIGNAL TAP. everythings is ok. The VGA exports exactly the data saved in the SDRAM. I also have clock 25MHz for the output.

Can somebody help to solve this problem and explain why ?

Thanks very much :)

4 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    12 years ago

    --- Quote Start ---

    plz, I need some help :(

    --- Quote End ---

    I think the idea is to use RGB as basic colors, use 24 bit register for RGB i.e. 8 bit for each R, G& B. Even i am having problem with the code to get all colors.:cry:
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    12 years ago

    Perhaps a dumb question but are your outputs mapped to the correct pins?

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    12 years ago

    Hi bao09,

    I'm doing the same project with you, but mine is to transfer image from SD card to SDRAM first, then display on VGA. Now, I read successfully from SD Card, but the SDRAM and VGA are stuck. Could you tell me about the timing, initialization of VGA and how VGA get the data from SDRAM, please ?

    By the way, are you using Nios-II or STORM SoC ?

    Thanks very much.