USB field programming

[teva]

Hi,

I want to start using the STM32U073KCU6 MCU in an upcoming product but don't have a ton of familiarity with STM MCUs.

My attraction to the device is based around the integrated USB functionality and I am trying to figure out if it can be field programed using the USB lines only (and of course being powered on).

What do I need to do in my pcb to make sure this is possible? what software tools (command line scripts or otherwise) do you recommend for this programming step?

Best,

Teva

[FBL]

Hi @teva 

> field programed using the USB lines

You mean DFU IAP application? Check this firmware example using STM32G0 and MB1933 schematics to interface USB peripheral on U083 discovery kit.

Getting started with STM32U0 MCUs hardware development application note should be helpful.

[Tesla DeLorean]

I'm thinking the question is more about if the System Loader supports "STM32 DEVICE" type DFU programming with tools like STM32 Cube Programmer. Per AN2606

 https://www.st.com/resource/en/application_note/an2606-stm32-microcontroller-system-memory-boot-mode-stmicroelectronics.pdf#page=444 

[teva]

Yeah thats right. Specifically what i want is the ability to have application code running over USB CDC and the ability to flash it over the same lines without reset (It looks like DFU is the main option for this), 

[FBL]

Hi @Tesla DeLorean  @teva 

First, configure the USB device as a composite class to enable both CDC communication and DFU for firmware updates. Ensure endpoints are assigned to each class. Next, implement a software mechanism to trigger a jump to the system loader, to enter DFU mode.