USB_OTG_HS and STM32CubeMX

[gil_he]

hello,

I have a USB-C connector connected to USB_DP2/DM2 in the OSD32MP157C.

The interface is used as USB HS OTG, slave only, with Dual_Role_Device option.

The USB-C connector uses only DP/DM and VBUS and these are connected to the Octavo.

1. In the STM32CubeMX I defined USB_OTG_HS only in A7NS (Linux).

I get the message: “Status: Partly disabled conflict with: SDMMC2: Mode MMC 8 bits Wide bus”.

I am also using eMMC Flash on SDMMC2 (which is defined in all stages: BOOT ROM , FSBL and A7NS).

What is the meaning of this status?

2. I chose OTG/Dual_Role_Device Type C (we are using a type C connector).

Should I check “Activate_SOF” and/or “Activate_VBUS”?

thank you

Gil

[gil_he]

hello Neeraj,

In addition to the above:

It seems there is an issue with PA8 I chose for SDMMC2_D4.

When choosing PB8 or PE4 the conflict is not there.

PA8 also occupies the role of OTG_HS_SOF.

If PA8 is used as SDMMC2_D4, OTG_HS_SOF cannot be asserted externally.

However, internally, this token can be used and is used as part of the protocol.

Am I correct with all that I wrote?

Will we have an issue with our USB interface?

thanks,

Gil

• This reply was modified 2 years, 3 months ago by gil_he.

[Neeraj Dantu]

Gil,

“Status: Partly disabled conflict with: SDMMC2: Mode MMC 8 bits Wide bus“:  This kind of error occurs when there is a pin conflict, which means you are trying to use the same pin in 2 interfaces. In this case PA8 is needed for OTG_HS_SOF. You can move the SDMMC2_D4 to other pins that are available.

Please check whether you need SOF function as in most cases/reference designs, it is not used to implement a generic USBC interface. See https://www.st.com/resource/en/application_note/dm00389996-getting-started-with-stm32mp151-stm32mp153-and-stm32mp157-line-hardware-development-stmicroelectronics.pdf USB chapter for more information on USB use cases.

Best,

Neeraj

[gil_he]

Hi Neeraj,

The design is over. For the current board revision.

SDMMC2_D4 is routed to PA8.

If I do not need this functionality, can I use the USBS interface without any issues?

There is no SOF pin on the USBC connector. Does a design that do use this functionality, need to route some signal to this pin? (internally in the board).

thanks,

Gil

[Neeraj Dantu]

Gil,

SOF pin serves as an indicator to indicate a start of frame and not needed for core USB function. You can use the pin for SDMMC.

Best,

Neeraj

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