Embedded Design Handbook

ID 683689
Date 8/28/2023
Public
Document Table of Contents

3.4.1. Endianness

The term endian describes data byte ordering in both hardware and software. The two most common forms of data byte ordering are little endian and big endian. Little endian means that the least significant portion of a value is presented first and stored at the lowest address in memory. Big endian means the most significant portion of a value is presented first and stored at the lowest address in memory. For example, consider the value 0x1234. In little endian format, the 4 is the first digit presented or stored. In big endian format, the 1 is the first digit presented or stored.

Endianness typically refers only to byte ordering. Bit ordering within each byte is a separate subject covered in “PowerPC Bus Byte Ordering” and “ARM BE-32 Bus Byte Ordering”.