8-bit


8-bit
Processors
1-bit 4-bit 8-bit 12-bit 16-bit 18-bit 24-bit 31-bit 32-bit 36-bit 48-bit 60-bit 64-bit 128-bit
Applications
8-bit 16-bit 32-bit 64-bit
Data Sizes
bit   nibble   octet   byte
halfword   word   dword   qword
IEEE floating-point standard
Single precision floating-point format (32-bit)  Double precision floating-point format (64-bit)  Quadruple precision floating-point format (128-bit)

In computer architecture, 8-bit integers, memory addresses, or other data units are those that are at most 8 bits (1 octet) wide. Also, 8-bit CPU and ALU architectures are those that are based on registers, address buses, or data buses of that size. 8-bit is also a term given to a generation of computers in which 8-bit processors are the norm.

The first widely adopted 8-bit microprocessor was the Intel 8080, being used in many hobbyist computers of the late 1970s and early 1980s, often running the CP/M operating system. The Zilog Z80 (compatible with the 8080) and the Motorola 6800 were also used in similar computers. The Z80 and the MOS Technology 6502 8-bit CPUs were widely used in home computers and game consoles of the '70s and '80s. Many 8-bit CPUs or microcontrollers are the basis of today's ubiquitous embedded systems.

There are 28 (256) possible values for 8 bits.

The first microprocessors had a 4-bit word length and were developed around 1970. The first commercial microprocessor was the BCD-based Intel 4004 (1971), developed for calculator applications. The first commercial 8-bit processor was the Intel 8008 (1972) which was originally intended for intelligent terminals. Most competitors to Intel started off with such character oriented 8-bit microprocessors. Modernized variants of these 8-bit machines are still one of the most common types of processor in embedded systems.

Important 8-bit CPUs

Eight-bit CPUs use an 8-bit data bus and can therefore access 8 bits of data in a single machine instruction. The address bus is typically a double octet wide (i.e. 16-bit), due to practical and economical considerations. This implies a direct address space of only 64 KiB on most 8-bit processors.

Early and/or popular 8-bit processors (incomplete):

See also



Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Bit rate — Bit rates Decimal prefixes (SI) Name Symbol Multiple kilobit per second kbit/s 103 megabit per second Mbit/s 106 gigabit per second Gbit/s 109 …   Wikipedia

  • Bit manipulation — is the act of algorithmically manipulating bits or other pieces of data shorter than a byte. Programming tasks that require bit manipulation include low level device control, error detection and correction algorithms, encryption algorithms, and… …   Wikipedia

  • Bit — Saltar a navegación, búsqueda Bit es el acrónimo de Binary digit. (dígito binario). Un bit es un dígito del sistema de numeración binario. Mientras que en el sistema de numeración decimal se usan diez dígitos, en el binario se usan sólo dos… …   Wikipedia Español

  • BIT — (binary digit) Contraction de l’expression anglaise binary digit (chiffre binaire), le terme bit prend en informatique trois significations différentes. Puisqu’on se trouve ici dans un système de numération à base 2, deux symboles (habituellement …   Encyclopédie Universelle

  • Bit — [bɪt], das; [s], [s]: kleinste Einheit der Informationseinheit beim Computer: ein Byte besteht aus acht Bit; ein Bit steht entweder auf 0 oder auf 1. * * * bịt 〈EDV; Zeichen für〉 Bit * * * 1Bịt , das; [s], s <aber: eine Million Bits od.… …   Universal-Lexikon

  • bit — bit1 [bit] n. [ME < OE bite, a bite < bītan, BITE] 1. the part of a bridle that goes into a horse s mouth, used to control the horse: see BRIDLE 2. anything that curbs or controls 3. the part of a pipestem held in the mouth: see PIPE 4. th …   English World dictionary

  • bit — Ⅰ. bit [1] ► NOUN 1) a small piece or quantity. 2) (a bit) a short time or distance. 3) (also bit of fluff or stuff) informal a girl or young woman. ● a bit …   English terms dictionary

  • Bit Cloud — is a character from , an anime based on TOMY s Zoids model franchise. Voiced by Takahiro Sakurai in the Japanese version and Richard Ian Cox in the English version of the series, he is the protagonist of the story, and a member of the Blitz team …   Wikipedia

  • Bit Corporation — (普澤 Pu Ze in Chinese) [cite web |url=http://fuji.drillspirits.net/gamate/?p=bit |title=Gamate: Bit Corporation |accessdate=2008 06 09 |author=Taizou |date=2008 |work=Neo Fuji |publisher=] was a Taiwanese game developer and console… …   Wikipedia

  • Bit Corp — Bit Corporation war ein taiwanischer Spiele und Konsolen Hersteller. Inhaltsverzeichnis 1 Spiele 2 Hardware 3 Anmerkungen 4 Weblinks // …   Deutsch Wikipedia

  • Bit (informatique) — Bit Pour les articles homonymes, voir Bit (homonymie).  Ne doit pas être confondu avec byte. Unités de bits Préfixes SI …   Wikipédia en Français


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.