42.6.2.3 Prescaler Selection

The GCLK_PDEC is fed into the internal prescaler. Prescaler outputs from 1 to 1/1024 are directly available for selection by the counter and all selections are available in Prescaler register (PRESC). If the prescaler value is higher than 0x01, the counter update condition is executed on the next prescaled clock pulse.

If the counter is set to count events, the internal prescaler is bypassed and the GCLK_PDEC clock is automatically selected during operation. The prescaler clock is also enabled when the input filtering is required.