Purpose: Flash, EEPROM, SRAM, and external-memory geometry.

Namespace: atmega2560::memory.

The 8 KB internal SRAM occupies 0x0200..0x21FF. External SRAM can be mapped above it through XMEM, subject to bus configuration.

#include <atmega2560/Memory.h>
 
namespace mcu = atmega2560;
 
static_assert(mcu::memory::sram_start_address == 0x0200, "ATmega2560 Memory definition");

Memory map

Region	Range / capacity
General register file	0x0000–0x001F
I/O registers	0x0020–0x01FF
Internal SRAM	0x0200–0x21FF (8 KB)
External mapped memory	0x2200–0xFFFF when XMEM enabled
Program Flash	256 KB (1024 pages × 256 B)
EEPROM	4 KB (512 pages × 8 B)

SRAM and Flash use different address spaces. Never use a Flash word address as a data-space register address.

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

Source: ATmega2560 datasheet (DS40002211A).