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SJA1105S RGMII Interfacing to PHY

Question asked by Martin Bishop on Mar 30, 2020
Latest reply on Apr 1, 2020 by bpe


I'm having a fight getting an SJA1105S, port 4 = SGMII as MAC, to talk to a DP83869HM PHY's SGMII port.

A few specific questions:

1) Is there any documentation of how to effect the configuration other than UM11040 and the python configuration tool, there is certainly scope for some.

2) Is the SGMII port expected to interface to the PHY "out of the box", my impression is that quite a bit of parameter twidling is required in the 1Fxxxx registers

3) Is one - one connection of the SGMII pipes correct, i.e. no polarity inversion- the default is Tx inverted

4) How should the SGMII be configured for test/use and what tests can one execute to prove functionality / identify the issue

More broadly, I can (and have) dumped registers and can tweak registers.  Pages of hex can be provided.  The link reports RxLinkUp, but does not complete auto neg and has a status of LinkDown.  The other port in use, port 0 on RGMII, seems fairly happy - looking at its status registers and traffic is being presented to port 4.

Wisdom on how to proceed would be appreciated

Best Regards