Need help understanding the voltage levels of ethernet chip pins

I'd like to use one of the following chips/boards but I first need to figure out what the voltage levels are on the RMII side (TXD_0, TXD_1, RXD_0, RXD_1 or RXIP, RXIN, TXOP, TXIN for the third chip). Each of the datasheets has an electrical specifications section where probably the required information is hidden in plain sight for me. However none of the parameters listed there refers directly to one of the pins so hopefully someone can help me figuring out what the voltage levels are on the respective pins.

1.
https://www.waveshare.com/dp83848-ethernet-board.htm
datasheet: https://www.waveshare.com/w/upload/1/1c/DP83848C.pdf

2.
**broken link removed**
datasheet: https://ww1.microchip.com/downloads/en/DeviceDoc/8720a.pdf

3. see attachment

The voltage levels an/or signal coding for 10Mb, 100Mb, Gb, and 10Gb Ethernet all are different. Wikipedia has pages for them with basic descriptions that probably will answer your questions.

ak