Clock.h

Purpose: Clock sources, fuse encodings, startup information, and prescalers.

Namespace: atmega328p::clock

The source enum describes the external clock, crystal options, internal calibrated RC, and internal 128 kHz RC. CKSELCode and SUTCode describe fuse encodings. Prescaler describes the system clock divisors.

#include <atmega328p/Clock.h>
 
namespace mcu = atmega328p;
 
constexpr mcu::clock::Source source =
    mcu::clock::Source::InternalCalibratedRC;
constexpr mcu::clock::Prescaler divider =
    mcu::clock::Prescaler::Divide8;
 
static_assert(mcu::clock::internal_calibrated_rc_hz == 8000000UL,
              "Internal RC nominal frequency");

The configured CPU frequency belongs in the consuming MCUConfig.h. This header describes available hardware choices; it does not change the clock.