STM32F750 TouchGFX Custom Board Flicker Like Problem

[yldzmuhammed]

Hello,

I am working on my custom board and build a project with CubeMX.

In my project, i used STM32F750N8, W25Q128 in memory mapped mode, 24 TFT LCD, TouchGFX.

When i build and load the project, pictures dont loading correct way. In the video you can see what i am talking about.

Why is this happining? Is this about sdram timing issue, or ltdc clock config?

https://www.youtube.com/watch?v=Eh2085DjMLc

[Martin KJELDSEN]

Hi, looks like it could be SDRAM configuration. Could you double check settings?

/Martin

[yldzmuhammed]

Hello @Martin KJELDSEN​ 

Sorry for my late response. I was working with new STM32CubeMX (5.4). It was hard to implement my old (5.3) project to the new one. 5.4 giving me vierd errors.

Anyway, when i write 0x00 or 0xFF (did not try any different value);

for(uint32_t *i = (uint32_t *)SDRAM_DEVICE_ADDR; i < (uint32_t *)(SDRAM_DEVICE_ADDR + SDRAM_DEVICE_SIZE); i++)
		*i = 0xFFFFFFFF;
 
for(uint32_t *i = (uint32_t *)SDRAM_DEVICE_ADDR; i < (uint32_t *)(SDRAM_DEVICE_ADDR + SDRAM_DEVICE_SIZE); i++)
		*i = 0x00000000;

there is no problem. But if i dont write any thing to the SDRAM, problem occurs.

I am using MT48LCM16A2TG SDRAM. Here is CubeMX timing values;

I checked values from datasheet. But i dont know why did happing.

So, if it is about sdram configuration, Why no problem occurs when i clear sdram?

[ldanu]

Are you already solve the problem?

Did you use MPU for ltdc buffer?

I've flickering issue when using ltdc, and it solve after i using MPU for ltdc buffer.

Or have you check the contact of lcd connection?