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MC74AC256 MC74ACT256 Dual 4ĆBit Addressable Latch
The MC74AC256/74ACT256 dual addressable latch has four distinct modes of operation which are selectable by controlling the Clear and Enable inputs (see Function Table). In the addressable latch mode, data at the Data (D) inputs is written into the addressed latches. The addressed latches will follow the Data input with all unaddressed latches remaining in their previous states. In the memory mode, all latches remain in their previous states and are unaffected by the Data or Address inputs. To eliminate the possibility of entering erroneous data in the latches, the enable should be held HIGH (inactive) while the address lines are changing.
MC74ACT256 Datasheet
