hf_division2.v

插值滤波器,用于音频解码调制解调,滤波器系数用移位相加实现

`timescale 1ns/10ps
module hf_division2(data_in,clock,reset,data_out);

input [19:1] data_in;
input clock,reset;
output [18:1] data_out;

reg [18:1] data_out;
reg [38:1] temp_data;

always@(posedge clock or negedge reset)
   begin
     if(!reset)
        begin
          data_out=0;
          temp_data=0;
        end  
     else
        begin
          temp_data={data_in,19'b0000000000000000000};
          temp_data=(temp_data>>9)+(temp_data>>15)+(temp_data>>18);
          if(temp_data[19]==1)
             data_out=temp_data[37:20]+1;
          else
             data_out=temp_data[37:20];   
         end    
   end 
endmodule           
         


//000000001000001001 ??9?15?18?