During a period of REFNUM/fCLK_REF, the FREQM is counting the number of periods of the clock to
be measured, VALUE. Here, REFNUM is the Number of Reference Clock Cycles selected in the
Configuration A register (CFGA.REFNUM), VALUE is the Measurement result stored to the Value register
(VALUE.VALUE), and fCLK_REF is the frequency of the reference clock.
The frequency of the measured clock, fCLK_MSR, is calculated by
fCLK_MSR=VALUEREFNUMfCLK_REF