Bit Slicing - Operational Details

Operational Details

Bit slice processors usually consist of an arithmetic logic unit (ALU) of 1, 2, 4 or 8 bits and control lines (including carry or overflow signals that are internal to the processor in non-bitsliced designs).

For example, two 4-bit ALUs could be arranged side by side, with control lines between them, to form an 8-bit CPU, with four slices a 16-bit CPU can be built, and it takes 8 four bit slices for a 32-bit word CPU (so the designer can add as many slices as required to manipulate increasingly longer word lengths).

A microsequencer or Control ROM would be used to execute logic to provide data and control signals to regulate function of the component ALUs. Examples of bit-slice microprocessor modules can be seen in the Intel 3000 family, the AMD Am2900 family, the National Semiconductor IMP-16 and IMP-8 family, and the 74181.