Signed number addition of two negative numbers and overflow
condition.
EX1: 
Step 1: Convert to 2's complement for negative numbers.


Step 2: Add & store the result in sum register 5 bits wide.
1 001
1 010
=====
10 011
=====
Step 3: No carry into signed bit but carry out of signed bit. In this scenario keep MSB as sign and take 2’s complement of lower 4 bits.
Result: 5’b1 1101 = 0x1D = 