the aip74hc/hct258 have four identical 2-input multiplexers with 3-state outputs, which select 4 bits of data from two sources and are controlled by a common data select input (s).
the data inputs from source 0 (1i0 to 4i0) are selected when input s is low and the data inputs from source 1 (1i1 to 4i1) are selected when s is high.
data appears at the outputs (1y to 4y) in inverted form from the select inputs.
the aip74hc/hct258 is the logic implementation of a 4-pole, 2-position switch, where the position of the switch is determined by the logic levels applied to s. the outputs are forced to a high impedance off-state whenoe is high.
the logic equations are:
1y=oe× (1i1×s 1i0×s)
2y=oe× (2i1×s 2i0×s)
3y=oe× (3i1×s 3i0×s)
4y=oe× (4i1×s 4i0×s)
the aip74hc/hct258 is identical to the aip74hc/hct257 but has inverting outputs.
for aip74hc258: cmos level
for aip74hct258: ttl level
inverting data path
3-state outputs interface directly with system bus
specified from -40℃ to 105℃
packaging information: dip16/sop16/tssop16