四位全加器

四级全加器

一：四位全加器代码
module add_4
(
input[3:0] a,b,
output[3:0] sum,
output cout,
input cin
);
assign{cout,sum} = a+b+cin;
endmodule

二：四位全加器激励模块代码
module adder_4();
wire[3:0] sum;
wire cout;
reg[3:0] a,b;
reg cin;
initial
begin
#0 a = 4’b0001; b = 4’b1010; cin = 1’b0;
#5 a = 4’b0010; b = 4’b1010; cin = 1’b1;
#5 a = 4’b0010; b = 4’b1110; cin = 1’b0;
#5 a = 4’b0011; b = 4’b1100; cin = 1’b1;
#5 a = 4’b0111; b = 4’b1001; cin = 1’b0;
#5 a = 4’b0001; b = 4’b1100; cin = 1’b1;
#5 a = 4’b0011; b = 4’b1100; cin = 1’b0;
#5 a = 4’b0111; b = 4’b1111; cin = 1’b1;
#5 $finish;
end
add_4 u1(.a(a),.b(b),.cin(cin),.sum(sum),.cout(cout));
endmodule
三：将代码导入Modelsim进行仿真，结果如下；

四：用QuartusII导入代码，导出电路图