74ABT646A

The 74ABT646A high-performance BiCMOS device combines low static and dynamic power dissipation with high speed and high output drive.

The 74ABT646A transceiver/register consists of bus transceiver circuits with 3-State outputs, D-type flip-flops, and control circuitry arranged for multiplexed transmission of data directly from the input bus or the internal registers. Data on the A or B bus will be clocked into the registers as the appropriate clock pin goes High. Output
Enable (OE) and DIR pins 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 both.

transferred through the device in real-time. The DIR determines which bus will receive data when the OE is active (Low). In the isolation mode (OE = High), data from Bus A may be stored in the Bregister and/or data from Bus B may be stored in the A register.When an output function is disabled, the input function is still enabled and may be used to store and transmit data. Only one of the two buses, A or B, may be driven at a time. The examples on the next page demonstrate the four fundamental bus management functions that can be performed with the 74ABT646A.