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 paper investigates four types of carry-tree adders the Brent-Kung, Kogge-Stone, the Slansky and Han-Carlson adder and compares them to the simple Ripple Carry Adder (RCA).

Just to chime in, i would be very supprised to see a 4 bit adder that did not have a carry out and in bit on it. I know with the chip we use, 74LS283, it is internally made up of 4 1 bit adders ...