Humm. Are 1v and 2.4v advertised so it can be auto negotiated? Maybe a
PHY tunable is not correct? Is this voltage selection actually more
like pause and EEE?

[Goes and looks at the datasheet]

Register 0x20E, bit 13:

1 = Advertise that the 10BASE-T1L PHY has increased transmit/
receive level ability
0 = Do not advertise that the 10BASE-T1L PHY has increased
transmit/receive level ability (default)

So does this mean 2.4v?

 	Andrew