//  D-Flip Flop with active low reset and active low preset
//  for Pseudo Random Bit Sequence Generator
//  Author:  Andrew Iverson
//  Date:  11-9-99
//------------------------------------------------------

module dff(q, d, clk, n_reset);
  output q;
  input d, clk, n_reset;
 
  reg q;

  always @ (posedge clk or negedge n_reset)

  begin
    if (!n_reset) 
      q <= 1'b0;
    else
      q <= d;
  end

endmodule