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 [2*size-1 : 0] a,b;
reg  [2*size-1 : 0]temp0,temp1,temp2,temp3;
assign a=mul_a;
assign b=mul_b;
always @(posedge clk or negedge rst_n)
begin
if(!rst_n)
begin
temp0<=0;
temp1<=0;
temp2<=0;
temp3<=0;
end
else
begin
temp0 <= b[0] ? a : 0;
temp1<=  b[1] ? a<<1 : 0; 
temp2<=  b[2] ? a<<2 : 0; 
temp3<=  b[3] ? a<<3 : 0; 
end
end
always @ (posedge clk or negedge rst_n)
begin
if(!rst_n)
begin
mul_out=0;
end
else
begin
mul_out=temp0+temp1+temp2+temp3;
end

end
endmodule