I can't read sdram framebuffer with LTDC

[123scy321]

I am developping STM32F469 with TouchGFX to display with LTDC in RGB888. I can display an image in the internal SRAM. However, when trying with SDRAM, the screen truns black, and the debugger can only read 0s. But when I tried with the framebuffer reader offered by ST, I can still read the image which seems to be already loaded into the SDRAM. Is there any suggestions to figure out the issue to give a final solution?

[KDJEM.1]

Hello @123scy321 and welcome to the community;

 

Could you please check the SDRAM configuration for that you can refer to How to set up the FMC peripheral to interface with the SDRAM IS42S16800F-6BLI from ISSI article.

Also, I recommend you to take a look at AN4861 application note precisely "5.5.2 Optimizing the LTDC framebuffer fetching from external memories (SDRAM or SRAM)" and "5.5.3 Optimizing the LTDC framebuffer fetching from SDRAM" sections.

 

I hope this help you!

Thank you.

Kaouthar