I wonder why the input from the mux has to be “deglitched.” Is it due to noise or that the input lines are not synchronized with the clock? Also because it’s g

I wonder why the input from the mux has to be “deglitched.” Is it due to noise or that the input lines are not synchronized with the clock? Also because it’s going to a CMOS input you really need to watch the RC time constant. If it’s too large, the input mosfets will both conduct for a relatively long period of time (called “shoot through”) and may cause the IC to malfunction, potentially permanently. Also he has no discharge diode connected to the cap in that circuit, which could cause the cap to discharge damaging amounts of current through the IC on power down if the cap is relatively large. Also you have to make sure the resistor is large enough to avoid damaging inrush currents from the input mux to the cap. That RC filter really bothers me. Maybe it really is necessary to “deglitch” but if so he should really include the values he used because naively selecting rc values there will cause potentially serious errors. A Schmitt trigger buffer would be far less error prone.