STM32H753VIH6 RMII

[Manikandan]

Hi Team,

We are using the STM32H753VIH6 in our design.

We are connecting the Realtek RTL8364 through RMII interface.

Connections are in the attachment and we have validated link between the two.

I have captured the waveforms , but the voltage span looks incorrect(going beyond 3.3V)  because the STM is powered by 3.3V.

Need inputs to capture proper waveforms.

Thanks

Manikandan R

[STOne-32]

Dear @Manikandan ,

Looking to the waveforms, there is a serious issue with signal integrity !  can you please share your schematics and lines RMII Terminations ? including the Clock of 50MHz and how is generated.  So, Our valuable community members  can help further.

Ciao

STOne-32.

[Manikandan]

Hi

The STM32 and Realtek RTL8364 are connected with 0E resistor in series.

[Manikandan]

Dear ST community,

Any inputs on the Voltage span of the signals will be much appreciated.

Thanks

Manikandan R

[mƎALLEm]

Hello,

I think better to inspire from one of the ref designs of ST boards:

From Nucleo-H743 schematics:

From STM32H743-Eval schematics:

[Manikandan]

Dear ST community,

Is the external PU is mandatory?

As per this reference let me introduce 33E in the series path of CLK, RXD0,RXd1,CRS_DV and will capture the waveforms.

Any inputs on the Voltage span ?

Thanks 

Manikandan R

[Manikandan]

Hi Team,

Sorry for the delayed response.

The previous attached images are captured with 200Mhz of 2GSa/s Oscilloscope with probe capacitance of 11pF

The attached images currently captured with the 2GHz of 8GSa/s Oscilloscope with probe capacitance of 1pF.

Would like to know the undershoot levels are accepted or not.

Thanks