darom.v

《数字信号处理的FPGA实现》代码

//*********************************************************
// IEEE STD 1364-1995 Verilog file: darom.v 
// Author-EMAIL: [e-mail]
//*********************************************************
//`include "220model.v"

module darom (clk, x_in0, x_in1, x_in2, y); //--> Interface

  input         clk;
  input  [2:0]  x_in0, x_in1, x_in2;
  output [5:0]  y;
  reg    [5:0]  y;
  reg    [2:0]  x0, x1, x2;
  wire   [2:0]  table_in, table_out;

  reg [5:0] p;  // Temporary register
  wire ena;

  assign ena=1; 

  assign table_in[0] = x0[0];
  assign table_in[1] = x1[0];
  assign table_in[2] = x2[0];

  always @(posedge clk)  //----> DA in behavioral style
  begin : DA
    parameter s0=0, s1=1;
    reg [0:0] state;
    reg [1:0] count;   // Counts the shifts
    case (state) 
      s0 : begin  // Initialization
        state <= s1;
        count = 0;
        p  <= 0;           
        x0 <= x_in0;
        x1 <= x_in1;
        x2 <= x_in2;
      end
      s1 : begin               // Processing step
        if (count == 3) begin  // Is sum of product done?
          y <= p;              // Output of result to y and
          state <= s0;         // start next sum of product
        end
        else begin
          p <= {p[5],p[5:1]} + {1'b0,table_out,2'b00};
          x0[0] <= x0[1];
          x0[1] <= x0[2];
          x1[0] <= x1[1];
          x1[1] <= x1[2];
          x2[0] <= x2[1];
          x2[1] <= x2[2];
          count = count + 1;
          state <= s1;
        end
      end
      default : ;
    endcase  
  end

  lpm_rom #(3,3,8,"UNREGISTERED","UNREGISTERED","darom3.hex") rom_1
  (.address(table_in), .q(table_out),         // Used ports
   .inclock(clk), .outclock(clk), .memenab(ena)); // Unused
//  defparam rom_1.lpm_width = 3;    
//  defparam rom_1.lpm_widthad = 3;
//  defparam rom_1.lpm_outdata = "UNREGISTERED"; 
//  defparam rom_1.lpm_address_control = "UNREGISTERED";
//  defparam rom_1.lpm_file = "darom3.hex";

endmodule