P2020 rgmii voltage ok with 3.3v?

[pauljohnson]

It is unclear whether it is ok to operate the P2020 RGMII port at 3.3v?

[sureshbk]

dear paul,

LVDD can be set to 3.3v or 2.5v which is the IO voltage of ethernet .if you change the LVDD to 3.3v , PHY also has to operate at 3.3V and all IO signals between processor and PHY should operate at 3.3V

[pauljohnson]

Thanks Suresh.  My concern was that the P2020EC manual states that the RGMII is spec'd for 2.5v, no mention of 3.3v.

Yes, I do have both sides at 3.3v and it is operational.

[sureshbk]

refer datasheet page 31

refer reference manual page 152

[pauljohnson]

Reference manual statement highlighted.  While it states that RGMII is defined for 2.5v, it does not state that it cannot operate at 3.3v.  I modified a board that is using GMII at 3.3v to use that same port as RGMII at 3.3v.  So far it is ok.  I suppose that the two pages that you indicated imply that since RGMII is available on the three speed Ethernet I/O it is ok to use RGMII with 3.3v.  Thanks.