Purpose: Logical GPIO pin and port identifiers.

Namespace: atmega2560::pin and device-level aliases.

#include <atmega2560/Pin.h>
 
namespace mcu = atmega2560;
 
static_assert(static_cast<unsigned>(mcu::pin::Pin::PL5) == 0xA5, "ATmega2560 Pin definition");

Logical pin encoding

The high nibble encodes the ordinal GPIO port (A=0, B=1, C=2, …, H=7, J=8, K=9, L=10). The low nibble encodes the bit position. Example: Pin::PB0 is 0x10; Pin::PL5 is 0xA5.

This encoding is independent of the Arduino Mega digital pin numbers and the physical 100-terminal package layout.

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

Source: ATmega2560 datasheet (DS40002211A).