The architectural specification of unaligned data representations is defined in terms of bytes transferred between memory and register, regardless of bus width and bus endianness.

Little-endian data items are described using lower-case byte labeling bX ... b0 (byteX to byte 0) and a pointer is always treated as pointing to the least significant byte of the addressed data.

Big-endian data items are described using upper-case byte labeling B0 ... BX (BYTE0 to BYTEX) and a pointer is always treated as pointing to the most significant byte of the addressed data.