Can't think of a simper way. So you could connect the voltage to an RC differentiator (capacitor in series with resistor to ground). The output will be a plus voltage for a rising signal, a negative voltage for a falling signal, and zero volts for no change. You could then use a couple of comparators from that to generate the digital signals you want. The amount that the voltage is above or below zero depends upon the rate-of-change of the signal and the RC time-constant.
If you want to use a single supply voltage, you can connect the capacitor to a voltage divider of equal value resistors to the supply voltage. Then the output will be above 1/2 the supply for a positive going signal, below 1/2 the supply for a negative going signal, and equal to 1/2 the supply for no signal change.