Ripple-Carry Adder for 2s complement

[divB]

Hi,

I have designed a simple 4 bit adder for adding two 4-bit unsigned integers A and B.
The adder consists of a chain of 4 Full-Adders (Ripple-Carry adder).

I am wondering if I need to change the circuit when A and B are in 2s complement.

I don't think so. Isn't the advantage of 2s complement that the circuit does not change?

Thanks

 

[divB]

Sorry, I think I need to modify it regarding the carry: The carry must be discarded when the last 2 stages have a carry ...