The FCT16823AT/BT/CT/ET and FCT162823AT/BT/CT/ ET 18-bit bus interface registers are built using advanced, dual metal CMOS technology. These high-speed, low-power registers with clock enable (xCLKEN) and clear (xCLR) controls are ideal for parity bus interfacing in high-performance synchronous systems. The control inputs are organized to operate the device as two 9-bit registers or one 18-bit register. Flow-through organization of signal pins simplifies layout. All inputs are designed with hysteresis for improved noise margin. The FCT16823AT/BT/CT/ET are ideally suited for driving high-capacitance loads and low-impedance backplanes. The output buffers are designed with power off disable capability to allow "live insertion" of boards when used as backplane drivers.