A fast/slow state machine latch is provided that generates fast and slow
select signals for a single toggle, low power multiplexer circuit. In
accordance with an embodiment of the present invention, the fast/slow
state machine latch includes a first latch with a delayed output, a
second latch with an undelayed output, an inverter for coupling the
delayed output of the first latch to an input of the second latch, and an
exclusive-OR (XOR) gate coupled to the delayed output of the first latch
and a data input, an output of the XOR gate coupled to an input of the
first latch. A method for incorporating low power multiplexer circuits
into a circuit design with minimal input from a circuit designer is also
provided.