carry look ahead adder.v

module four_bit_carryLookAhead_adder(s, cout, a, b, cin);
	
	
	input [3:0] a, b;
	input cin;
	output [3:0] s;
	output cout;
	
	wire [3:0] p, g, c;
	
	assign g = a&b;
	assign p = a^b;
	
	assign c[0] = cin;
	assign c[1] = g[0] | (p[0]&c[0]);
	assign c[2] = g[1] | (p[1]&c[1]);
	assign c[3] = g[2] | (p[2]&c[2]);
	assign cout = g[3] | (p[3]&c[3]);
	
	assign s = p^c;

endmodule

// module carry_look_ahead_adder(s, cout, a, b, cin);
//     input [3:0] a, b;
//     input cin;
//     output [3:0] s;
//     output cout;
//     wire [3:0] p, g, c;
//     assign p = a ^ b;
//     assign g = a & b;
//     assign c[0] = cin;
//     assign c[1] = g[0] | (p[0] & c[0]);
//     assign c[2] = g[1] | (p[1] & g[0]) | (p[1] & p[0] & c[0]);
//     assign c[3] = g[2] | (p[2] & g[1]) | (p[2] & p[1] & g[0]) | (p[2] & p[1] & p[0] & c[0]);
//     assign cout = g[3] | (p[3] & g[2]) | (p[3] & p[2] & g[1]) | (p[3] & p[2] & p[1] & g[0]) | (p[3] & p[2] & p[1] & p[0] & c[0]);
//     assign s = p ^ c;
// endmodule