Subversion Repositories qaz_libs

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//// Copyright (C) 2015 Authors and OPENCORES.ORG                 ////
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//////////////////////////////////////////////////////////////////////


module
  one_hot_encoder
  #(
    A,  // encoder select width
    D = 2 ** A
  )
  (
    input   [A-1:0] select,
    output  [D-1:0] encoded
  );

  // --------------------------------------------------------------------
  //
  localparam W = 2 ** (A-1);


  // --------------------------------------------------------------------
  //
  generate
    if(A == 1)
    begin: one_hot_encoder_gen
        assign encoded[1:0] = select[0] ? 2'b10 :2'b01;
    end
    else
    begin: recurse_one_hot_encoder_gen
      wire [W-1:0] encoder_out;

      one_hot_encoder #(.A(A - 1))
        one_hot_encoder_i
        (
          .select(select[A-2:0]),
          .encoded(encoder_out)
        );

      assign encoded = select[A-1] ? {encoder_out, {W{1'b0}}} : {{W{1'b0}}, encoder_out};
    end
  endgenerate


// --------------------------------------------------------------------
//
endmodule