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November 10, 2025
Question

How to erase external flash using STM32_Programmer_CLI.exe and flash loader?

  • November 10, 2025
  • 1 reply
  • 209 views

MCU : STM32U5G9ZJT6Q
External Flash : MX25LM51245G
SPI Interface : HSPI1

 

When I use STM32_Programmer_CLI.exe I cannot erase the external flash.

Board info:

dev_info.png

 

 

 

 

 

 

I get following error from STM32_Programmer_CLI.exe:

 

STM32_Programmer_CLI.exe -c port=SWD -el "C:\Users\USER\Desktop\Workspace\External_Loader\MX25LM51245G_STM32U5G9ZJ\Project\EWARM\Debug\Exe\MX25LM51245G_STM32U5G9ZJ.stldr" -e all

-------------------------------------------------------------------
STM32CubeProgrammer v2.20.0
-------------------------------------------------------------------

ST-LINK SN : 56FF70067287555130422267
ST-LINK FW : V2J46S7
Board : --
Voltage : 3.21V
SWD freq : 4000 KHz
Connect mode: Normal
Reset mode : Software reset
Device ID : 0x476
Revision ID : Rev Z
Device name : STM32U5Fx/5Gx
Flash size : 4 MBytes
Device type : MCU
Device CPU : Cortex-M33
BL Version : 0x90
Debug in Low Power mode enabled


Mass erase ...

Error: Mass erase operation failed.Please verify flash protection

 

How can I do that please?

I looked forums and communities and I have to say the info is rather hopeless.

1 reply

Technical Moderator
November 13, 2025

Hello @Dong_Dong ,

Is TZEN enabled?

This may be a known issue and limitation for STM32U5 when TZEN is enabled: 

STM32CubeProgrammer errata 2.20.x

  • STM32L5 and STM32U5 microcontrollers: Unable to read, write, or erase the external flash memory when TZEN is enabled.
"When your question is answered, please close this topic by clicking ""Accept as Solution"".ThanksImen"
Dong_DongAuthor
Associate
November 14, 2025

TZEN is disabled....

 

https://community.st.com/t5/stm32-mcus/how-to-implement-and-use-your-own-external-flash-loader-an/ta-p/597752

I created an External Loader with reference to that document.

Did I misorganize the file?


https://github.com/STMicroelectronics/stm32-mx25um51245g

Drivers related to flash memory referenced the file.

The "discovery" driver included the file "stm32u5g9j_xx".
Changed "MX66UW1G45G_xx" to "MX25LM51245G_xx".


https://github.com/Dong-Dongs/External_Loader

I will attach my project link together