The F139 is a high-speed, dual 1-of-4 decoder/demultiplexer. It has two independent decoders, each accepting two inputs and providing four mutually exclusive active LOW outputs. Each decoder has an active LOW Enable input which can be used as a data input for a 4-out- put demultiplexer. Each half of the F139 can be used as a function generator providing all four minterms of two vari- ables.