题解 | #4bit超前进位加法器电路#
4位数值比较器电路
http://www.nowcoder.com/practice/e02fde10f1914527b6b6871b97aef86d
`timescale 1ns/1ns
module lca_4(
input [3:0] A_in ,
input [3:0] B_in ,
input C_1 ,
output wire CO ,
output wire [3:0] S
);
wire [4:0] G,P,C;
assign G = A_in&B_in;
assign P = A_in^B_in;
assign C[0] = C_1;
assign C[1] = G[0]|(P[0]&C[0]);
assign C[2] = G[1]|(P[1]&(G[0]|(P[0]&C[0])));
assign C[3] = G[2]|(P[2]&(G[1]|(P[1]&(G[0]|(P[0]&C[0])))));
assign C[4] = G[3]|(P[3]&(G[2]|(P[2]&(G[1]|(P[1]&(G[0]|(P[0]&C[0])))))));
assign CO = C[4];
assign S = P^C;
endmodule

