题解 | #流水线乘法器#

`timescale 1ns/1ns

module multi_pipe#(
	parameter size = 4
)(
	input 						clk 		,   
	input 						rst_n		,
	input	[size-1:0]			mul_a		,
	input	[size-1:0]			mul_b		,
 
 	output	reg	[size*2-1:0]	mul_out		
);

wire [size*2-1:0] temp [size-1:0];

assign temp[0] = mul_b[0] ? {4'b0,mul_a}:8'b0;
assign temp[1] = mul_b[1] ? {3'b0,mul_a,1'b0}:8'b0;
assign temp[2] = mul_b[2] ? {2'b0,mul_a,2'b0}:8'b0;
assign temp[3] = mul_b[3] ? {1'b0,mul_a,3'b0}:8'b0;

reg [size*2-1:0] sum1 [0:1];

always @(posedge clk or negedge rst_n)begin
	if(!rst_n)begin
		sum1[0] <= 8'b0;
		sum1[1] <= 8'b0;
	end
	else begin
		sum1[0] <= temp[0] + temp[1];
		sum1[1] <= temp[2] + temp[3];
	end
end

always @(posedge clk or negedge rst_n)begin
	if(!rst_n)begin
		mul_out <= 'b0;
	end
	else begin
		mul_out <= sum1[0] + sum1[1];
	end
end

endmodule