Hi, Karthik,
This is my opinion, as you know that the FlexBus is used to read/write memory or memory-mapped device, the FlexBus data pins logic can not keep forever, when the memory accessing is over, the data bus logic are unknown.
If you want to read/write IO, how about using GPIO pins, the K65 has a lot of GPIO pins, for example PortA, PortB, PortC, PortD...
Hope it can help you
BR
Xiangjun Rong