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External loader

Associate III


I am using STM32H745 microcontroller and w25q512 External loader QSPI But i have used ST link  for creating external loader but getting verification fail error   

It successfully complete Read , write and erase but while i verifying it give "Verification Failed error "


Your QSPI configuration is as follows:

  • IO3 ----> PF6
  • IO2 ----> PF7
  • IO1 ----> PF9
  • IO0 ----> PF8
  • QSPI CLK ----> PB2
  • QSPI NCS ----> PG6

I have attempted to use various files from the GitHub repository  (, but i consistently encounter an "Erase failed" error. Upon examining the configurations available, it seems none matches your specific setup for QSPI.

Although i found a configuration (h7_w25q256) similar to mine, i encountered the same "Flash Erase failed" error.

One notable observation is that the file sizes of the configurations are considerably smaller compared to my generated .stldr file.


Please let me help for this its bit urgent


ST Employee

some reference for QSPI/OSPI external flash loader for STM32H7 boards can be found here:

stm32-external-loader/STM32H7x_boards at main · STMicroelectronics/stm32-external-loader · GitHub


As you use STLINK as hardware programmer/debugger, and I suppose you use STM32CubeProgrammer as software programmer, it is recommended to design your own external flash loader based on official external loader examples.


I have already created own external flash loader based on official external loader examples. 

but while verifying code it gives error on any one address (expected output 0x00 and actual is 0x99).

Is there any other reason for this please guide me