Touchgfx without GFXMMU

[farukisiker]

I have a problem with disabling gfxmmu. I don't have a rounded display so that actually I do not need GFXMMU.

I created a project by using Touchgfx Designer Templates (STM32H7S78 DK BPP). GFXMMU is activated in default. I would like to disable it. So, I disable it in cubemx then exclude instrumantation files. Then I updated TouchgfxHal.cpp and frame buffer adresses as 0x9000 0000 - 0x9020 0000.

Then I could succesfully build the project. When I run it, it is working particularly but the frame/image is broken down. I am adding the image here!

Could you explain me how to enable or disable gfxmmu properly from project?

[JohanAstrup · Accepted solution]

Hello @farukisiker.

We currently provide three TBSs in TouchGFX Designer for STM32H7S78-DK. From your description, it sounds like you selected the one called “STM32H7S78 DK 24 BPP”. As mentioned in the description for this TBS, it uses the GFXMMU to achieve 24 bpp framebuffers, which are not natively supported by NeoChrom GPU on this MCU.

I recommend using the default TBS for STM32H7S78-DK, named “STM32H7S78 Discovery Kit”, which uses 16 bpp framebuffers. You can also easily switch to 32 bpp by changing the color format in the LTDC configuration in STM32CubeMX.

Alternatively, you can complete your modifications to the 24 bpp TBS, which will effectively give you the same end result as using the default TBS with 32 bpp. To do this, you need to do the exact opposite of the 20 steps described here in the TouchGFX Documentation.

Best regards,
Johan