The SN54SC8T139-SEP is used to control multiple devices that operate on a shared data bus. A decoder provides the capability to have a binary encoded input activate only one of the device's outputs. This is ideal for solid state memory applications where multiple devices have to be read or written to with a limited number of GPIO pins used on the system controller. The decoder is used to activate the chip select (CS) input to the selected memory device, and the controller can then read or write from that device alone when using a shared bus.