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_a_t [size-1:0];
integer i;
integer j;
always @ (posedge clk or negedge rst_n) 
begin
    if(~rst_n) begin
        for(i = 0; i < size; i = i+1) begin
            mul_a_t[i] <= 'b0;
        end 
    end 
    else begin
        for(j = 0; j < size; j = j+1) begin
            mul_a_t[j] <= mul_b[j] ? mul_a << j : 'b0;
        end
    end 
end                                                   
reg [size*2-1:0] sum_t[size-1:0];
integer n;
always @ (*) 
begin
    for(n = 0; n < size; n = n+1) begin
        if(n == 0) 
            sum_t[0] = mul_a_t[0];
        else
            sum_t[n] = sum_t[n-1] + mul_a_t[n];
    end 
end                                           

always @ (posedge clk or negedge rst_n) 
begin
    if(~rst_n) begin
        mul_out <= 'b0;
    end 
    else begin
        mul_out <= sum_t[size-1];
    end 
end     
endmodule