K60 100MHz does implement an arbitration scheme that allows for sharing between the FlexBus and NFC.
There is no related register to switch the NFC and Flexbus.
About Flexbus and NFC related pin setting, there with two situations:
1> this sharing is really only used for the NFC data lines/FlexBus AD lines and the NFC_WE and FlexBus R/W signals. If you look at the signal muxing table in the manual you can see that these pins only have a single function selection for FlexBus/NFC. For example, PTB20 function ALT5 is “FB_AD31/NFC_DATA15.” So this is a case where the pin is configured for a FB/NFC mode and dynamically switches between the two.
In the case of the control signal pins that (NFC_CE0 and NFC_RB) the pins for these signals have different programmed functions to choose between the FlexBus and NFC signals on the pins. So for those signal the pin does not dynamically switch between the functions. It is fixed as a FlexBus or NFC pin based on whether you choose ALT5 or ALT6.
Wish it helps.
