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Geethat
Associate II
May 26, 2025
Solved

Need Guidance on QSPI External Loader Issue with Custom Board Using STM32H750

  • May 26, 2025
  • 3 replies
  • 1149 views

We are currently working on a project using the STM32H750IBT6 microcontroller interfaced with a single-bank Quad SPI NOR Flash (MT25QL512ABB) on our custom board. The QSPI interface is operational.

However, we are facing an issue with the external loader. While the same external loader setup works correctly with the STM32H750 development board using the same two MT25QL512ABB Flash memories, it fails to function on our custom board.

Development board QSPI schematic:

Screenshot (1).png

 Our custom board QSPI schematic:

Screenshot (2).png

 For reference, we are used the external loader implementation for development board from the following link:

 https://controllerstech.com/w25q-flash-series-part-8-quadspi-external-loader/ 

We request your support in:

  • Verifying if our schematic connections for the QSPI interface may be contributing to the issue.

  • Identifying any possible hardware or configuration-related causes for the external loader failure.

Best answer by Geethat

 Thanks for all the support, the issue has been resolved with changing the dummy cycles of qflash from 10 to 8, now iam able to read and write to qflash with external loader attached

 

3 replies

KDJEM.1
Technical Moderator
May 26, 2025

Hello @Geethat and welcome to the community;

 

Have you tested the MT25L01G_STM32H750B-DISCO external loader in STM32CubeProgrammer with your customer board?

KDJEM1_0-1748266313941.png

I think, you can use the external loader "MT25TL01G_STM32H750B-DISCO" [support memory Size = 128M] for your QSPI memory MT25QL512ABB8ESF-0SIT [memory Size = 64B] because the size of your memory is less than the external loader supported by STM32CubeProgrammer.

For hardware checking, I recommend you to refer to AN4938  precisely section "9.4.3 Quad serial parallel interface (QUADSPI)"

KDJEM1_1-1748266667417.png

 

I hope this help you.

Thank you.

Kaouthar

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Geethat
GeethatAuthor
Associate II
May 27, 2025

Yes, we have tested the external loader MT25TL01G_STM32H750B-DISCO in STM32CubeProgrammer with our custom board, but it did not work.

Could you please advise on the next steps? and also verify our custom board schematic whether it is correct or not.

The errors we have received are as follows:

Media (3).jpeg

 

Media (4).jpeg

 

KDJEM.1
Technical Moderator
May 28, 2025

Hello @Geethat;

 

You’re used (PB2, PB6, PD11, PD13, PE2, and PF9) a different QSPI pins used by STM32H750B-DK (PF10, PF9, PG6, PD11, PF7, and PF6). So, you can’t run MT25L01G_STM32H750B-DISCO external loader in STM32CubeProgrammer.

I recommend you to look at MOOC - External QSPI loader how to - YouTube and get inspired to create your own external loader.

 

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.
Tesla DeLorean
Guru
May 27, 2025

What pins on the STM32 side? Enumerate what you built so we can validate.

The DISCO/DK board loader expects a pair of parts which interleave, it won't work with half the parts.

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Geethat
GeethatAuthor
Associate II
May 28, 2025

For the development kit, the QSPI connection pin names can be directly found in the email description.
For my custom board, you can refer to the image below for the QSPI pin details which are highlighted.

Screenshot 2025-05-28 151213.png

thank you. 

for more information you can also find my colleague Post link is: Issue with Single QSPI Flash Functionality Using E... - STMicroelectronics Community




Geethat
GeethatAuthorBest answer
Associate II
June 2, 2025

 Thanks for all the support, the issue has been resolved with changing the dummy cycles of qflash from 10 to 8, now iam able to read and write to qflash with external loader attached

 

Senior
February 5, 2026

Hey,

I’ve ended up with the same MCU and flash memory on my custom board. 
did you end up using a boot loader to launch from internal flash, as 128KB is too small for TouchGFX?