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		
);

reg	[size*2-1:0] mul_out_r0, mul_out_r1, mul_out_r2,mul_out_r3;



always@(posedge clk, negedge rst_n) begin
if(rst_n==1'b0) begin
	mul_out_r0 <= 'b0;
	mul_out_r1 <= 'b0;
	mul_out_r2 <= 'b0;
	mul_out_r3 <= 'b0;
	mul_out    <= 'b0;
end
else begin
 mul_out_r0 <= mul_a[0] ?  mul_b              : 'b0 ;
 mul_out_r1 <= mul_a[1] ? ({3'b0,mul_b,1'b0}) : 'b0 ;
 mul_out_r2 <= mul_a[2] ? ({2'b0,mul_b,2'b0}) : 'b0 ;
 mul_out_r3 <= mul_a[3] ? ({1'b0,mul_b,3'b0}) : 'b0 ;
 mul_out    <=  mul_out_r0 + mul_out_r1 + mul_out_r2 + mul_out_r3;
end
end


endmodule