Little-endian

Little-endian is a term used in computer science to describe a specific method of byte ordering in digital computers. It is a way of organizing the bytes of a word in memory, where the least significant byte (LSB) has the lowest address and the most significant byte (MSB) has the highest. This method is used in the storage of multibyte data types such as integers and floating point numbers in computer memory or during transmission over networks.

Overview

In a little-endian system, when a multibyte value is stored in memory, the least significant byte is stored at the smallest address and the most significant byte at the highest. For example, the 32-bit hexadecimal number 0x12345678 would be stored in memory as 78 56 34 12. This approach is opposite to big-endian, where the most significant byte is stored at the smallest address.

History

The term "little-endian" comes from Jonathan Swift's 1726 satire Gulliver's Travels, where it was used metaphorically to describe one of the reasons for a war between two fictional countries: the proper way to crack open a boiled egg. In the context of computer architecture, the term was popularized by Danny Cohen in 1980 in a paper titled "On Holy Wars and a Plea for Peace" which discussed the byte ordering wars of the time.

Usage

Little-endian byte ordering is used by many modern computer architectures, including the x86 architecture used in most personal computers, making it a widely adopted standard. Other architectures, such as ARM, can operate in either little-endian or big-endian mode, depending on the configuration.

Advantages and Disadvantages

One advantage of little-endian ordering is that it can be more efficient when performing certain arithmetic operations, as the least significant bytes, which are often the focus of calculations, are accessed first. However, it can be argued that little-endian is less intuitive than big-endian ordering when reading memory dumps, as the bytes appear in reverse order from what might be expected.

Comparison with Big-endian

The choice between little-endian and big-endian often comes down to the specific requirements of the application and the hardware architecture. While little-endian is more common in desktop computing, big-endian is often found in networking protocols, where it is sometimes referred to as network byte order.

See Also

• Endianness
• Computer architecture
• Byte
• Integer (computer science)
• Floating point