10.4.2 Operation
The GCLK peripheral consists of four Generic Clock Generators that can provide a generic clock for the 13 Peripheral Channels and the Main Clock (GCLK_MAIN).
A clock source selected as input to a generator can either be used directly or prescaled in the generator. A generator output is used by one or more peripheral channels to provide a Peripheral Generic Clock Signal (GCLK_PERIPH) to the peripherals.
Note: Only Generator 0 (GCLK_GEN0) can provide a clock signal to the
Main Clock (GCLK_MAIN).
