12.3.6 Timebase
The timebase is used to generate a timing period equal to or longer than 1 µs, used for timing internal delays such as ADC start-up time, which is done by setting the TIMEBASE bitfield in the Timebase (CLKCTRL.MCLKTIMEBASE) register to a count of CLK_PER cycles that is equivalent to or larger than 1 µs. Round the timebase up to the closest integer.