The HD74ALVCH16245 is designed for asynchronous communication between data buses. The control function implementation minimizes external timing requirements. This device can be used as two 8-bit transceivers or one 16-bit transceiver. It allow data transmission from the A bus to the B bus or from the B bus to the A bus depending upon the logic level at the direction control (DIR) input. The output enable (OE ) input can be used to disable the device so that the buses are effectively isolated. Active bus hold circuitry is provided to hold unused or floating data inputs at a valid logic level.