Hai..., I am using STM32F746IGT custom boar QUADSPI W25Q128A and custom External Loader CLIVEONE "Stldr" file for PF7,PB6,PB2,PF9,PF8,PF6 PIn configuration , When i go to Debug mode geting error.

[GMano.1]

Erasing memory corresponding to segment 0:

Erasing internal memory sectors [0 4]

Error: failed to erase memory

Error: failed to erase memory

Encountered Error when opening C:\ST\STM32CubeIDE_1.6.0\STM32CubeIDE\plugins\com.st.stm32cube.ide.mcu.externaltools.cubeprogrammer.win32_1.6.0.202101291314\tools\bin\STM32_Programmer_CLI.exe

Error in STM32CubeProgrammer

Debugger connection lost.

Shutting down...

What i do? Where i do mistakes? Where i get exact External Loader file for STM32F746IGT MCU

Thank you

[Tesla DeLorean]

Perhaps you can get more verbose and specific error information?

Run STM32 Cube Programmer independently, set the verbose level higher and test and evaluate read, erase, write, etc.

What exactly is your "custom" hardware configuration?

Have you done any basic bring-up testing of the QSPI memory to know if your implementation even works?

Can you read the JEDEC ID from the Winbond Memory? How about read some blocks in the 1, 2 and 4-bit modes?

There isn't an "exact" loader for the STM32F746IGT MCU, it's more about the F7 MCU and how you've wired the QSPI memory, and if it's functional.

Perhaps find the QSPI BSP code for the DISCO boards, and modify that to suit.