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Black lines when using DMA2D on STM32H7 with SDRAM

JSpan.1
Associate

Hi,

I am using TouchGFX 4.13 on a STM32H750XB.

I'm using a 800x480 screen, so the framebuffers are placed in external SDRAM.

My code is based of the example project for the STM32H750B-DK, and almost

everything seems to be working except for the fact that I get black lines when enabling the Chrom-Art.

Here is an example of what it looks like:

0693W000001qxUwQAI.png

These lines seem to appear when dma2d is used to add an image to the framebuffer.

(Some TiledImages are used, explaining the seemingly random lines at the left/bottom).

When the Chrom-Art is not used, everything looks fine.

Similar code has worked when using a smaller screen and placing the framebuffers in AXI-SRAM, so my guess is that this problem has something to do with the SDRAM, but I can't figure out what it is I'm doing wrong.

Does anybody have any suggestions?

4 REPLIES 4
Martin KJELDSEN
Chief III

To rule out issues with DMA2D you could try using the NoDMA class instead of your current one (STM32DMA probably). If the issue remains then could be SDRAM.

/Martin

JSpan.1
Associate

I've found the solution, the pins for FMC_NBL were not initialized properly.

Great! :)

Thanks a lot! 

I was stuck in this same problem. 

Solved here.