Fill a part of frame buffer with a L8 format color on STM32H7

[Gpeti]

Hello,

i'm using DMA2D to fill a part of my frame buffer with a single color. Environnement​ is STM32H753, LTDC controller, EVAL2 board with LCD screen.

Until now I was using ARGB8888 format (so both input and output formats were identical in DMA2D setting) but now I switched to L8 format.

I don't understand why there is no "L8" output color format ? I just want the DMA to copy the L8 color index to the buffer in memory, I actually don't need any conversion, nor CLUT.

There is probably something I didn't understand in the DMA2D behaviour.

Thank you

[oleksandr.karbivsky]

Hi. In Ref Manual you can find supported output formats on page 709. L8 format is not supported.

You can use MDMA for Memory-to-Memory transaction with 1 byte data size settings.

[Gpeti]

​Thank you for your answer. Would it work for with MDMA ? I thought a benefit of DMA2D is to be able to manage offset (from one image line to another one).

Also I don't really understand why the easiest mode (I mean no color conversion at all) is not supported.

[oleksandr.karbivsky]

MDMA also has offset configuration. L8 is not common format for graphical applications.