The SN54 / 74LS298 is a Quad 2-Port Register. It is the logical equivalent of a quad 2-input multiplexer followed by a quad 4-bit edge-triggered register. A Common Select input selects between two 4-bit input ports (data sources.) The selected data is transferred to the output register synchronous with the HIGH to LOW transition of the Clock input. The LS298 is fabricated with the Schottky barrier process for high speed and is completely compatible with all Motorola TTL families.