1-bit architecture

Not to be confused with bit or One instruction set computer.

"1-bit" redirects here. For the oversampling digital-to-analog converter technology, see 1-bit DAC.

Bit
1 4 8 12 16 18 24 26 31 32 36 48 60 64 128 256 512
Application
16 32 64
Floating point precision
×½ ×1 ×2 ×4 ×8
Floating point decimal precision
32 64 128

A 1-bit computer architecture is an instruction set architecture for a processor that has datapath widths and data register widths of 1 bit (1/8 octet) wide.

An example of a 1-bit architecture that was actually marketed as a CPU is the Motorola MC14500B Industrial Control Unit. There are also several design studies for 1-bit architectures in academia, and corresponding 1-bit logic can also be found in programming.

Most calculators used a bit serial design before using 4-bit and later up to 32-bit processors.

Other examples of 1-bit architectures are programmable logic controllers.

A typical sequence of instructions from a program for a 1-bit architecture might be:

• load digital input 1 into a 1-bit register;
• OR the value in the 1-bit register with input 2, leaving the result in the register;
• write the value in the 1-bit register to output 1.

1-bit CPUs can be considered obsolete now, not many kinds have been produced (MC14500B and WDR-1 known) and none known to be available in any computer component store (except, as of 2014, a few on eBay).

See also

• Bit slicing

External links

• WDR-1-Bit Computer