I got an adder cell, which in IC mirror layout is this:
EDIT: Transistor-level, standard adder circuit:
Which I actually made in IC like this:
It's not working as it should! I labelled it same as in the first figure, so the labels themselves are ok, but the signals are like this:
As you can see, the sum signal S is working as it should, but the carry output is buggy. Not only that, the COUT and notCOUT are not opposite, so sth is definitely wrong. I throuroughly examined the circuit, but can't find where I made a mistake.
Can anyone spot the error? THANKS!!