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Furkan2
Furkan2
Associate II
May 13, 2026
Question

Unable to Store TouchGFX Assets in External Flash using OCTOSPI1

  • May 13, 2026
  • 3 replies
  • 486 views

I am trying to interface STM32U5G7VJT6 with MT25QL128A using OCTOSPI1 in Quad SPI mode, but I still cannot store/run TouchGFX assets from external flash memory.

Current configuration:

  • Memory Type: Micron
  • Device Type: Flash
  • Device Size: 24
  • Clock Prescaler: 2
  • Clock Mode: Low
  • Sample Shifting: Half Cycle
  • Wrap Size: Not Supported
  • Delay Block: Bypassed

Screenshot attached.
Could someone please check if I missed any important configuration like memory-mapped mode, linker settings, TouchGFX asset location, BSP/init sequence, or MT25QL128A command setup?

3 replies

KDJEM.1
KDJEM.1
Technical Moderator
May 13, 2026

Hello @Furkan2;

 

--> Screenshot attached.

Could you please add the screenshot.

Can you do read and write operations on the external flash memory?

I recommend you to look at AN5050 section "7 OCTOSPI application examples" may help you.

 

Thank you.

Kaouthar

 

 

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Furkan2
Furkan2Author
Associate II
May 13, 2026

Thank you for your response.

I have attached the OCTOSPI1 configuration screenshots and related settings.

Currently, I am not able to MT25QL128A external flash memory, so TouchGFX assets are also not working from external flash.

I will also check AN5050 section 7 as suggested.

KDJEM.1
KDJEM.1
Technical Moderator
May 18, 2026

Hello @Furkan2;

 

Thank you for these details.

Is the problem solved when displaying TouchGFX and read/write operations from external buffer?

 

Thank you.

Kaouthar

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Furkan2
Furkan2Author
Associate II
May 18, 2026

Dear Kaouthar,

Thank you for your support.

The external flash read/write operation is working correctly now, and the external buffer is accessible in memory-mapped mode.

However, the TouchGFX display issue is not fully solved yet. The LCD no longer stays completely white, but the image rendering is unstable/blurry and sometimes becomes white again during TouchGFX execution.

Currently:

  • External OSPI flash read/write: Working

  • Memory-mapped mode: Working

  • LTDC initialization: Working

  • Framebuffer in SRAM: Configured

  • TouchGFX rendering: Still unstable

I am currently checking LTDC timing and framebuffer configuration.

Thank you.

KDJEM.1
KDJEM.1
Technical Moderator
May 18, 2026

Hello @Furkan2;

 

I advise you to look at Introduction to LCD-TFT display controller (LTDC) for STM32 MCUs - Application note and How to set up the LTDC peripheral to interface with the display panel ATM0500D27-CT from AZ Displays may help you. 

 

 

Thank you.

Kaouthar

To give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.
Furkan2
Furkan2Author
Associate II
May 18, 2026

Thank you for your response.

I will review the application note “Introduction to LCD-TFT display controller (LTDC) for STM32 MCUs” and also check the example for interfacing the ATM0500D27-CT display panel.

Currently, the external OSPI flash memory is working correctly in memory-mapped mode, and read/write access is successful. However, the TouchGFX display is still showing a white/blurry screen issue.

I will verify the LTDC timing and framebuffer configuration again based on the provided references.

Thank you for your supports

M
mathiasmarkussen
ST Employee
May 21, 2026

TouchGFX works on a pixel level, so it should not be able to produce blurry images unless that is the intention. Artificial blur is quite an expensive operation.

It sounds more like an LTC setup problem to me.

You could try to read the framebuffers from memory using a debugger and look at known locations if the colour is correct.

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