From WikiChip
4-bit architecture
Revision as of 15:24, 24 January 2016 by ChipIt (talk | contribs) (4-bit microprocessors)

Architecture word sizes
v · d · e

The 4-bit architecture is a microprocessor or computer architecture that has a datapath width or a highest operand width of 4 bits or a nibble. These architectures typically have a matching register file with registers width of 4 bits and 4-8-bit wide addresses.

Industry

Most of the first microprocessors during the early 1970s had 4-bit word sizes. Both the Intel 4004, the first commercial microprocessor, and the 4040 had a 4-bit word length, but had 8-bit instructions. Some of the first microcontrollers such has the TMS1000 made by Texas Instruments and NEC's μPD751 also had 4-bit words.

4-bit word were proven to be very limiting and by 1974 there was a shift to larger architectures such as 8- and 12- bit architectures. Some 4-bit chips are still made to date such as the Epson's S1C60 and S1C63 MCU families. Modern 4-bit microprocessors, however, are much different to the first generation microprocessors of the 1970s - in terms of architecture, performance, and overall capabilities.

Applications

Most 4-bit microprocessors were used almost exclusively in calculators and toys, later on for various utilities, video games, controllers, and early computers. 4 bits was a logical choice for many calculators that used BDC numbers representation.

Today, 4-bit chips such as S1C60 family are still manufactured are used in many low-power devices, wireless tools, and internet of things.

4-bit microprocessors

4-bit microcontrollers