[Phillip] wanted to play with the C preprocessor. He decided to do that by creating a 4 bit full adder. We know this is pretty useless in everyday life, but it was a great learning experience. The ...

This paper focuses on the implementation and simulation of 4-bit, 8-bit and 16-bit carry look-ahead adder based on Verilog code and compared for their performance in Xilinx.

This infers a combinatorial circuit since there is no clock. The case statement is like a switch statement in C. The funny looking numbers are four bit hex (4’h1) and 7 bit binary (7’b1101101).