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DP83822I: RMII RX_DV relationship to RX_D content

Pascal REGACHE
Prodigy 240 points
Part Number: DP83822I

Hello,

I am looking for the relationship between RX_DV and the data content on the RX_D bus in RMII mode.

The RMII spec shows this for CRS_DV (asserted as soon as carrier detect and after a while, then preamble and data but no indication for the end of packet).

For RX_DV, the DP83822 indiactes on page 29:

"In addition, RMII mode supplies an RX_DV signal that allows a simpler method of recovering receive data
without the need to separate RX_DV from the CRS_DV indication. RX_ER is also supported even though it is not
required by the RMII specification."

So the questions are:

- is RX_DV asserted synchronously with the receiving of the preamble, and includes the whole preamble

- is RX_DV de-asserted right after the last piece of data ?

I checked on the DP83848 datasheet that provides more information, but is not fullty explicit about this (and nothing says that the two chips behave the same).

Thanks

Best regards

Pascal