Patent ID: 8037444

Claim:
An integrated circuit device comprising: mask-programmable circuitry that includes a first portion operable to store fixed data; post-fabrication-programmable circuitry; and multiplexer circuitry having a first selectable input coupled to receive a first output signal of the post-fabrication-programmable circuitry, a second selectable input coupled to receive an output signal of the first portion of the mask-programmable circuitry including the fixed data, a selection control input coupled to receive a second output signal of the post-fabrication-programmable circuitry, and an output providing a multiplexer output signal that is coupled to affect operation of a second portion of the mask-programmable circuitry, the multiplexer circuitry being controllable by the signal received via the selection control input to select which of the first and second selectable inputs the multiplexer circuitry couples to the output; wherein: the post-fabrication-programmable circuitry comprises memory circuitry, one-time programmable circuitry, or fuse circuitry; and the multiplexer circuitry allows an output signal of the post-fabrication-programmable circuitry to affect timing of a signal in the mask-programmable circuitry.