RMII just means it uses fewer I/O pins from the MCU as compared to MII. I don't remember the details either but it's possible that some chips support RMII and not MII because they don't have the additional I/O pins.
Tiva-C (arch/arm/src/tiva) supports RMII (the chip has the built-in MAC and PHY) so maybe you can use that as a general example. Of course the details of drivers for STM32 will be quite different. Cheers Nathan On Thu, Feb 29, 2024 at 2:15 PM Alan C. Assis <acas...@gmail.com> wrote: > Hi Roland, > > We had a discussion about it a few months ago! > > We know it is possible, but nobody until now tried to do it. > > Basically you will need RMII support on both chips, I don't remember the > details why MII will not work (or will be more difficult to work) > > There is a discussion about it here, maybe you can get more insights: > > https://stackoverflow.com/questions/39503466/can-two-ethernet-mac-chips-be-connected-directly-without-going-thru-phy > > Best Regards, > > Alan > > > On Thu, Feb 29, 2024 at 2:11 PM Roland <ning.rol...@mindpx.net> wrote: > > > Hi, > > > > I would like to directly connect a STM32F7 processor running Nuttx, to an > > external MCU (i.e., NXP imx8m) through RMII directly, without the need > for > > PHY IC in between. > > Is this supported by Nuttx? I checked into the documents but this direct > > mode seems not been mentioned anywhere. > > Can anyone please confirm if this is supported, or I have to change > > something by myself? > > > > Thank you. > > > > /Roland > > > > >
