The CY74FCT16646T and CY74FCT162646T 16-bit transceivers are three-state, D-type registers, and control circuitry arranged for multiplexed transmission of data directly from the input bus or from the internal registers. Data on the A or B bus will be clocked into the registers as the appropriate clock pin goes to a HIGH logic level. Output Enable (OE\) and direction pins (DIR) are provided to control the transceiver function. In the transceiver mode, data present at the high impedance port may be stored in either the A or B register, or in both. The select controls can multiplex stored and real-time (transparent mode) data. The direction control determines which bus will receive data when the Output Enable (OE\) is Active LOW. In the isolation mode (Output Enable (OE\) HIGH), A data may be stored in the B register and/or B data may be stored in the A register. This device is fully specified for partial-power-down applications using Ioff. The Ioff circuitry disables the outputs, preventing damaging current backflow through the device when it is powered down. The CY74FCT16646T is ideally suited for driving high-capacitance loads and low-impedance backplanes. The CY74FCT162646T has 24-mA balanced output drivers with current limiting resistors in the outputs. This reduces the need for external terminating resistors and provides for minimal undershoot and reduced ground bounce. The CY74FCT162646T is ideal for driving transmission lines.