This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

STM32F417IG USB HS with external PHY conflict with PB14 as GPIO

Hi,

We are facing a problem with the PB14 pin set as a GPIO and the USB HS with external PHY. we are using the PB14 to control la relay and USB communication using the ULPI interface. For what we understand if the USB is using ULPI then PB14 and PB15 should be free to be used as GPIO, but after the USB_Connect function is executed the PB14 seems to be taken by the USB driver or library. 

While debugging the code we can see the PB!4 works as a GPIO until this point, afterwards we cannot longer control the PB14. So looking at the pin assignment we notice the PB14 has the AF of OTG_HS_DM pin, so  that explains why the USB is messing with the PB14 configuration. What does not make sense is that this happens when the USB interface is set be using the external PHY, so the internal one (who uses PB14 and PB15) should be disabled.

Looking on the internet it seems another people with similar problems it seems that issue is on the USB driver but we cannot longer access the post they have (below a link to what we found).... Can you please let us know how to solve this?

community.st.com/.../stm32f4xx-spi2-and-usbhs-conflict

Regards

Mark Burger