Question: If IFCLK is external, can it be stopped (held low) at any point? For example when there is no activity on the slave FIFO interface (external master not accessing the FIFO interface).
Answer: The minimum frequency of IFCLK is 5 MHz. If you can be assured there is no communication with the host that would affect the slave fifos (ep2/4/6/8 transactions), then you can disregard this minimum and shut the clock off.
