The MC74AC258/74ACT258 is a quad 2-input multiplexer with 3-state outputs. It selects four bits of data from two sources under control of a common Select input. The four outputs present the selected data in the complement (inverted) form. The outputs may be switched to a high impedance state with a HIGH on the common Output Enable (OE) input, allowing the outputs to interface directly with bus-oriented systems.