题解 | 4bit超前进位加法器电路

`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 CO0,CO1,CO2;
	adder adder0 (A_in[0],B_in[0],C_1,S[0],CO0);
	adder adder1 (A_in[1],B_in[1],CO0,S[1],CO1);
	adder adder2 (A_in[2],B_in[2],CO1,S[2],CO2);
	adder adder3 (A_in[3],B_in[3],CO2,S[3],CO);

	
endmodule

module adder(
	input a,b,ci,
	output s,co

);

assign s = a ^ b ^ ci;
assign co = (a & b) | (a & ci) | (b & ci);
endmodule

全加器，秒