I am testing the ethernet on our custom board with a STM32H745IHx MCU attached to an 8740A phy chip. We want to use RMII mode. Currently, I am failing the loopback test. We are not sure why this failure is occurring.
I put my code on a nucleo board, and the loopback test works, so I don't think it's my code. This problem occurs only on our setup. I have included a schematic of our setup so you can see it clearly. The loopback mode is enabled by setting the l...