The MC74AC646/74ACT646 consist of registered bus transceiver circuits, with outputs, D-type flip-flops and control circuitry providing multiplexed transmission of data directly from the input bus or from the internal storage registers. Data on the A or B bus will be loaded into the respective registers on the LOW-to-HIGH transition of the appropriate clock pin (CAB or CBA). The four fundamental data handling functions available are illustrated in the following figures.
   
• Independent Registers for A and B Buses
• Multiplexed Real-Time and Stored Data Transfers
• Choice of True and Inverting Data Paths
• 3-State Outputs
• 300 mil Slim Dual In-Line Package
• Outputs Source/Sink 24 mA
• ′ACT646 Has TTL Compatible Inputs