题解 | #编写乘法器求解算法表达式#

`timescale 1ns/1ns

module calculation(
	input clk,
	input rst_n,
	input [3:0] a,
	input [3:0] b,
	output [8:0] c
	);

wire	[7:0]	pro0,pro1;

mult_4	u0
(
	.clk	(clk),
	.rst_n	(rst_n),
	.data_a	(4'd12),
	.data_b	(a),

	.prod	(pro0)
);


mult_4	u1
(
	.clk	(clk),
	.rst_n	(rst_n),
	.data_a	(4'd5),
	.data_b	(b),

	.prod	(pro1)
);

assign	c = pro0 + pro1;





endmodule



module	mult_4
(
input	wire	clk	,
input	wire	rst_n,
input	wire	[3:0]	data_a,
input	wire	[3:0]	data_b,

output	reg		[7:0]	prod
);
reg		[3:0]	mul0,mul1,mul2,mul3;

always@(posedge clk or negedge rst_n)
	if(!rst_n)
        begin
            mul0	<=  4'd0;
            mul1	<=  4'd0;
            mul2	<=  4'd0;
            mul3	<=  4'd0;
        end
    else
		begin
			mul0	<=	data_b[0]?	data_a:0;
			mul1	<=	data_b[1]?	data_a:0;
			mul2	<=	data_b[2]?	data_a:0;
			mul3	<=	data_b[3]?	data_a:0;
		end
always@(posedge clk or negedge rst_n)
	if(!rst_n)
		prod	<=	8'd0;
	else
		prod	<=	mul0 + (mul1 <<1) + (mul2 <<2) + (mul3 <<3);


endmodule