STM32 - DFU Methods
DFU stands for: Device Firmware Upgrade.
The STM32 family supports multiple firmware download methods.
Application note, AN2606, is titled: STM32 microcontroller system memory boot mode It documents the boot loaders on pretty much all the STM32 devices. https://www.st.com/resource/en/application_note/cd00167594-stm32-microcontroller-system-memory-boot-mode-stmicroelectronics.pdf Application note, AN3156, describes the USB DFU method https://www.st.com/resource/en/application_note/cd00264379-usb-dfu-protocol-used-in-the-stm32-bootloader-stmicroelectronics.pdf Application note, AN3155, describes Serial DFU method https://www.st.com/resource/en/application_note/an3155-usart-protocol-used-in-the-stm32-bootloader-stmicroelectronics.pdf Application note, AN4221, describes I2C protocol method https://www.st.com/resource/en/application_note/an4221-i2c-protocol-used-in-the-stm32-bootloader-stmicroelectronics.pdf Application note, AN3154, describes CAN DFU protocol https://www.st.com/resource/en/application_note/an3154-can-protocol-used-in-the-stm32-bootloader-stmicroelectronics.pdf Application note, AN4286, describes SPI protocol method https://www.st.com/resource/en/application_note/an4286-spi-protocol-used-in-the-stm32-bootloader-stmicroelectronics.pdf Other application notes may be available for other peripheral interfaces, such as the encabulator interface Here's a good web page for STM32CubeProgrammer to use with DFU: https://wiki.stmicroelectronics.cn/stm32mpu/wiki/STM32CubeProgrammer