When using CubeMX V4.18 with the Nucleo-144 board with STM32F767ZI processor to configure the Ethernet RMII, I discovered that using the MII pins as GPIO cause pin configuration warnings. For example, pin PB0 is not used by the RMII interface, but it is ETH_RXD2 for the full MII interface. On the Nucleo-144, it is the default connection to the LD1 [Green] LED. When PB0 is configured as GPIO_OUT for the LED, the Ethernet RMII interface flags the pin as conflicting with RMII. There are 2 possible explainations:
1. When Ethernet is enabled, ALL MII/RMII pins are reserved for Ethernet, and LED1 must be reconfigured to PA5.
2. PB0 is incorrectly flagged as conflicting by CubeMX and is still available for LED1.
Which of these are correct? I checked some other MII pins not used by RMII, and all MII pins create a conflict with RMII.