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September 19, 2024
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RMII diagrams

  • September 19, 2024
  • 2 replies
  • 1055 views

Hi, we are working with a STM32F217 and the RMII bus.

In the two documents reported I see an inconsistency on the diagrams (on the one hand rising edge sampling, on the other falling edge). Which one is correct for my chip?

RM0033 Figure 328 Reference Manual (01 Mar 2021) 

DS6697 Figure 48Product Specification (05 Sep 2016) 

 

BR

Stefano

    This topic has been closed for replies.
    Best answer by Imen.D

    Hi @StefanoRossi ,

    The RMII operates using the rising edge of the clock signal for both TX and RX data transfers.

    So, the DS6697 Rev 13 - Figure 48. Ethernet RMII timing diagram is the correct one.

    This RM0033 will be updated to fix the issue.

    2 replies

    Technical Moderator
    September 19, 2024

    Hello @StefanoRossi and welcome to ST Community,

    Thank you for having reported the point.

    I escalated this request to involved people for review and take the necessary action.

    (Internal ticket number: 191487 - this ticket number is only for reference, not available outside of ST)

    I'll make sure to post updates here as soon as possible. 

    Imen.DAnswer
    Technical Moderator
    September 23, 2024

    Hi @StefanoRossi ,

    The RMII operates using the rising edge of the clock signal for both TX and RX data transfers.

    So, the DS6697 Rev 13 - Figure 48. Ethernet RMII timing diagram is the correct one.

    This RM0033 will be updated to fix the issue.