Purpose: AVR CPU architecture.

Namespace: atmega2560::architecture.

#include <atmega2560/Architecture.h>
 
namespace mcu = atmega2560;
 
static_assert(mcu::architecture::program_counter_bits == 17, "ATmega2560 Architecture definition");

These are hardware definitions, not runtime register access or initialization.

Source: ATmega2560 datasheet (DS40002211A).