Honored Contributor
Honored Contributoryou need to look at subtractor result to verify if it works or not and not further in your design.
The subtractor design on the adder is something I haven't seen before but looking at it now. To convert 23:0 bits unsigned to negative they have to invert each bit then add 1. They are apparently doing something clever in this addition of 1. I am still looking at it. I can see 23:0 is mapped to 24:1 implying multiply by 2 then a 1 is added at bit 0 (implying half) then another 1 is added to bit0 of other input?? implying add another 1 and so 2 is added then possibly one lsb at output is discarded implying 2/2 = 1, thus 1 is added this way. But I am still not sure completely. So you check this adder and tell us.
