The FCT157T is a high-speed quad 2-input multiplexer built using an advanced dual metal CMOS technology. Four bits of data from two sources can be selected using the common select input. The four buffered outputs present the selected data in the true (non-inverting) form. The FCT157T has a common, active-low, enable input. When the enable input is not active, all four outputs are held low. A common application of FCT157T is to move data from two different groups of registers to a common bus. Another application is as a function generator. The FCT157T can generate any four of the 16 different functions of two variables with one variable common.