Text not displaying properly in RGB 888 mode with STM32H745

[ATank.1]

I am using STM32H745 with 16bit SDRAM and QSPI nor flash for images and TouchGFX for developing the screens. Am using 800x480 resolution.

I have developed some sample screens which look fine when 565 color mode is configured in LTDC and DMA2D and TouchGFX.

But when I configure the application to use 888 color mode I see some texts not displaying properly. Please see attached images.

Also if you see the slider in the image it leaves a trail when moved till end and back.

I think some screen refreshing issue is present in 888 color mode.

What could be the issue here. Is this due to bandwidth issues with SDRAM / LTDC

LCD is running at 29MHz as per calculation and SDRAM is runnining at 100MHz

I tried reducing the LCD clock or also increasing the clock but issue persists.

Thanks

Anuj

[MM..1]

tgfx version ? know bug ...

[ATank.1]

Thanks for the quick reply

TouchGFX version used is latest which is 4.21

[MM..1]

Compare with older

[Osman SOYKURT]

Hello ATank.1,

Your issue remined me this thread. Do you also work with L8 formats ?

By the way, which complier do you use ?

/Osman

[ATank.1]

Thanks for the reply

Am using STM32Cube IDE with default STM32 GNU toolchain (GCC compilier)

Am not using L8 formats at all. only use 565 or 888 configuration in CubeMX and TouchGFX Designer.

My texts are not cut but are not displayed clearly and observed with only some texts and slider Observe this issue only with 888 format and not 565 format.

Plan to verify with previous version of TouchGFX.

Thanks

Anuj

[Osman SOYKURT]

Hello ATank.1,

I've tried with a STM32H745-disco TBS and changed the Framebuffer Pixel Format to use RGB888 instead of RGB565. Couldn't reproduce the issue.

Do you use double buffering for framebuffer strategy ?

/Osman

[ATank.1]

Hi,

Thanks for trying that out. I have used double buffering. Will try to use single buffer and check. If still does not work then I have a discovery board, will port the same code and check.

Thanks

Anuj