Re: Connecting KSZ8863RLL to a MAC using RMII
I'm having the same problem with a very similar configuration. In my case it is the KSZ8864 (4-port) switch and a different wireless module that supports RMII.
I've looked at your schematic and I am using the same connections, and think the Rx/Tx connections look correct. But again, I'm having the same failure where the switch is working for other channels but not on this RMII channel.
I have the switch pin strapped so its RMII interface is PHY Mode (MAC-to-MAC), and similar to your schematic their are no MDIO serial connections between the switch and wireless module. I configured the switch for PHY Mode based on the fact that in this mode the switch's CRS_DV pin is an output, and on the WiFi module the CRS_DV line can only be an input. Maybe this is a false assumption, and the switch should be set for MAC Mode (MAC-to-PHY).
To answer your question, I don't think there are any registers in the switch that will confirm that it is pin strapped correctly and in RMII mode. At least I couldn't find anything with the KSZ8864 switch.
Have you made any progress with this problem?