I wrote it loader myself.mcu is STM32F429IIT6.There is only one GPIO function inside mcu, without any interruption.It is generated by STM32CUBEMX.If there is a program in FLASH of stm32 mcu, the download will fail. If I erase the internal program of ...

When failure, the following information is prompted.Error:Mass erase operation failed. please verify flash protection​

I wrote it loader myself.mcu is STM32F429IIT6.There is only one GPIO function inside mcu, without any interruption.It is generated by STM32CUBEMX.If there is a program in FLASH of stm32 mcu, the download will fail. If I erase the internal program of ...