Number of input channel and
select pins: A 4-input MUX requires two select pins. However, an 8-input MUX
requires three select pins.
The logic table: What select pin
configuration determines which input channel is selected as the output.
Interrupts: Interrupts must be
placed on all input channel and select pins as the output signal is generated by
setting or clearing the output signal based on the selected input channel.
Propagation delay: There is a
possibility for a propagation delay due to interrupts. The propagation delay is
based on the clock speed.