Reconfigurable computing refers to processing with highly flexible computing fabrics. The principal difference when compared to a microprocessor is the ability to make substantial changes to the datapath implemented in addition to the control flow.

The method used with some types of reconfigurable computer was to use a microcoded processor where the microcode was stored in RAM or EEROM and changed on reboot or on the fly. This could be done with the AMD 2900 series bit slice processors and later with Field programmable gate array where a processor reconfigures on the fly.