I'm attempting to implement Ethernet communication for the first time and have run into an issue with my PHY. I'm using the KSZ8091RNBCA. According to the datasheet, when running in RMII mode, the XO pin is supposed to be left unconnected (Tables 2-3, 3-2). Figure 3-4, shown below, shows that my external 50MHz crystal needs to be connected to both the XI pin on the PHY and the REF_CLK line.
Since both paths are shown coming out of the crystal, does REF_CLK come off the same pin as XI, or does it come off of the other pin, where the XO would normally go?