74259 IC 8-bit addressable latch

The 74HC259; 74HCT259 is an 8-bit addressable latch. The device features four modes of
operation. In the addressable latch mode, data on the D input is written into the latch addressed
by the inputs A0 to A3. The addressed latch will follow the data input, non-addressed latches
will retain their previous states. In memory mode, all latches retain their previous states and are
unaffected by the data or address inputs. In the 3-to-8 decoding or demultiplexing mode, the
addressed output follows the D input and all other outputs are LOW. In the reset mode, all outputs
are forced LOW and unaffected by the data or address inputs. Inputs include clamp diodes. This
enables the use of current limiting resistors to interface inputs to voltages in excess of VCC.