45.5.3 Clocks
The I2SMCC runs from the peripheral clock and the generic clock (GCLK), both generated by the Power Management Controller (PMC). Prior to using the I2SMCC, the user must first program the PMC. The I2S host and serial clock can be generated either from the peripheral clock or the generic clock.
In a similar way, the I2SMCC must be disabled before removing its clock source to avoid freezing it in an undefined state.