STM32MP2 without using a Type-C connector (no real UCPD CCx signals)

[VAley]

Hello.

We are developing a device with the STM32MP257 and we will not have a USB Type-C connector in our design. We plan to use the USB3DR as a USB2.0 device with a USB 2.0 connector to USB boot (USB boot for flashing). 

1. Does the STM32MP2 embedded bootloader uses the UCPD CCx signals?
2. How can we inform the USB3DR about detection of the USB VBUS?
3. Is is possible to emulate UCPD CCx signals (sink mode) from the USB VBUS as a variant of detecting the incoming USB power?

Best regards,

Vadim Aleynikov

[PatrickF]

Hi @VAley ,
for BootROM point of view, only DM and DP are required, any other signals are ignored to be as generic as possible. BootROM always be in 'device' mode.

Then, for TF-A and uBoot, device tree need to be aligned with your HW.
https://wiki.st.com/stm32mpu/wiki/USB3DR_device_tree_configuration#DT_configuration_example_as_USB2-speed_only_USB3DR_in_Peripheral_mode--with_micro-B-28ID_left_unconnected-29_or_Type-C_connector

If you are doing 'device' only, you could still put a type-C connector without any specific management of CC lines (just pull-downs)

See also AN5489 which could help you. e.g.

Regards.

[VAley]

Hi Patrick,

Thank you so much for your reply. 

Unfortunately, I cannot implement your suggestion for using a Type-C connector: in this design, the use of a microUSB connector is mandatory.

Best regards,

Vadim Aleynikov