The dac I am designing requires a parallel to serial input to increase the signal frequency .  Right now I want to make a ramp signal and send it through the parallel to serial interface to the dac, so the signal frequency becomes 8 times the original.  I am using multiplexors, to multiplex the signals from the counters.  There are six 8:1 muxes, the inputs for each 8:1 mux are the same except every other signal is inverted.  I drew up a timing diagram, and the way the mux selects the inputs will cause it to select to high signals in a row, which is not what I want.  Is there a way to do this with muxs?