The SN54ABT16541 and SN74ABT16541A are noninverting 16-bit buffers composed of two 8-bit sections with separate output-enable signals. For either 8-bit buffer section, the two output-enable (1 and 1 or 2 and 2) inputs must both be low for the corresponding Y outputs to be active.If either output-enable input is high, the outputs of that 8-bit buffer section are in the high-impedance state.