Page "Segmentation fault" Paragraph 4

; unaligned access: Most CPUs are byte-addressable, where each unique memory address refers to an 8-bit byte.

Most CPUs can access individual bytes from each memory address, but they generally cannot access larger units ( 16 bits, 32 bits, 64 bits and so on ) without these units being " aligned " to a specific boundary.

For example, if multi-byte accesses must be 16 bit-aligned, addresses ( given in bytes ) at 0, 2, 4, and so on would be considered aligned and therefore accessible, while addresses 1, 3, 5, and so on would be considered unaligned.

Similarly, if multi-byte accesses must be 32-bit aligned, addresses 0, 4, 8, 12, and so on would be considered aligned and therefore accessible, and all addresses in between would be considered unaligned.

Attempting to access a unit larger than a byte at an unaligned address can cause a bus error.