DM54LS259

DM54LS259 DM74LS259 8-Bit Addressable Latches May 1992 DM54LS259 DM74LS259 8-Bit Addressable Latches General Description These 8-bit addressable latches are designed for general purpose storage applications in digital systems Specific uses include working registers serial-holding registers and active-high decoders or demultiplexers They are multifunctional devices capable of storing single-line data in eight addressable latches and being a 1-of-8 decoder or demultiplexer with active-high outputs Four distinct modes of operation are selectable by controlling the clear and enable inputs as enumerated in the function table In the addressable-latch mode data at the datain terminal is written into the addressed latch The addressed latch 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 In the 1-of-8 decoding or demultiplexing mode the addressed output will follow the level of the D input with all other outputs low In the clear mode all outputs are low and unaffected by the address and data inputs Features Y Y Y Y Y Y Y Y Y Y 8-Bit parallel-out storage register performs serial-to-parallel conversion with storage Asynchronous parallel clear Active high decoder Enable disable inpu...