The FCT257T has four identical two-input multiplexers which select four bits of data from two sources under the control of a common data Select input (S). The I0 inputs are selected when the Select input is LOW and the I1 inputs are selected when the Select input is HIGH. Data appears at the output in true non-inverted form for the FCT257T. The FCT257T is a logic implementation of a four-pole, two position switch where the position of the switch is determined by the logic levels supplied to the select input. Outputs are forced to a high-impedance "OFF" state when the Output Enable input (OE) is HIGH.