Hardware changes required for programming through UART, USB DFU, I2C, SPI, and CAN bootloader interfaces

[SA.17]

• I am using STM32L072RB microcontroller,new to stm32cubeprogrammer,does all interfaces (UART, USB DFU, I2C, SPI, and CAN bootloader interfaces) support debug and programming ?
• What hardware changes are required to implement programming features via these interfaces ?
• Are these interfaces can be multiplexed . for e.g. same UART can be used to send data to PC and can be used to program microcontroller using PC ?
• Is this software free?
• Does my current microcontroller supports this or any specific requirements for using these interfaces for programming?

[Tesla DeLorean]

Try reviewing application note AN2606​

[Tesla DeLorean]

https://www.st.com/resource/en/application_note/cd00167594-stm32-microcontroller-system-memory-boot-mode-stmicroelectronics.pdf

The ROM loader comes on the parts as delivered.

The most critical hardware consideration is NOT to generate noise on interfaces other than the one(s) you want to use. For example don't connect a GPS receiver to a USART the loader is looking for.

Use an interface you expose. If you have a RS232 port on product, connect the boot loader USART to that, so you can program in factory or field.

If you don't normally provide a USART port, expose one to pin headers or test points for factory use.

[SA.17]

The document explains connection for uart and DFU USB,can i have some circuit example for Boot pin and how to set and reset nBoot1 bit.

[TDK]

The bootloader does not support debugging. It is meant for programming. The SWD interface (ST-Link) is meant for the usual programming/debugging.