The Clock Controller peripheral (CLKCTRL) controls, distributes, and prescales the clock signals from the available oscillators. The CLKCTRL supports internal and external clock sources.

The CLKCTRL is based on an automatic clock request system, implemented in all peripherals on the device. The peripherals will automatically request the clocks needed. If multiple clock sources are available, the request is routed to the correct clock source.

The Main Clock (CLK_MAIN) is used by the CPU, RAM, and the IO bus. The Main Clock source can be selected and prescaled. Some peripherals can share the same clock source as the Main Clock, or run asynchronously to the Main Clock domain.