The HCT138A decodes a threebit Address to oneofeight activelot outputs. This device features three Chip Select inputs, two activelow and one activehigh to facilitate the demultiplexing, cascading, and chipselecting functions. The demultiplexing function is accomplished by using the Address inputs to select the desired device output; one of the Chip Selects is used as a data input while the other Chip Selects are held in their active states.