module Computer_System_Expansion_JP1 (
                                       // inputs:
                                        address,
                                        chipselect,
                                        clk,
                                        reset_n,
                                        write_n,
                                        writedata,

                                       // outputs:
                                        bidir_port,
                                        irq,
                                        readdata
                                     )
;

  inout   [ 31: 0] bidir_port;
  output           irq;
  output  [ 31: 0] readdata;
  input   [  1: 0] address;
  input            chipselect;
  input            clk;
  input            reset_n;
  input            write_n;
  input   [ 31: 0] writedata;


wire    [ 31: 0] bidir_port;
wire             clk_en;
reg     [ 31: 0] d1_data_in;
reg     [ 31: 0] d2_data_in;
reg     [ 31: 0] data_dir;
wire    [ 31: 0] data_in;
reg     [ 31: 0] data_out;
reg     [ 31: 0] edge_capture;
wire             edge_capture_wr_strobe;
wire    [ 31: 0] edge_detect;
wire             irq;
reg     [ 31: 0] irq_mask;
wire    [ 31: 0] read_mux_out;
reg     [ 31: 0] readdata;
  assign clk_en = 1;
  //s1, which is an e_avalon_slave
  assign read_mux_out = ({32 {(address == 0)}} & data_in) |
    ({32 {(address == 1)}} & data_dir) |
    ({32 {(address == 2)}} & irq_mask) |
    ({32 {(address == 3)}} & edge_capture);

  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          readdata <= 0;
      else if (clk_en)
          readdata <= {32'b0 | read_mux_out};
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          data_out <= 0;
      else if (chipselect && ~write_n && (address == 0))
          data_out <= writedata[31 : 0];
    end


  assign bidir_port[0] = data_dir[0] ? data_out[0] : 1'bZ;
  assign bidir_port[1] = data_dir[1] ? data_out[1] : 1'bZ;
  assign bidir_port[2] = data_dir[2] ? data_out[2] : 1'bZ;
  assign bidir_port[3] = data_dir[3] ? data_out[3] : 1'bZ;
  assign bidir_port[4] = data_dir[4] ? data_out[4] : 1'bZ;
  assign bidir_port[5] = data_dir[5] ? data_out[5] : 1'bZ;
  assign bidir_port[6] = data_dir[6] ? data_out[6] : 1'bZ;
  assign bidir_port[7] = data_dir[7] ? data_out[7] : 1'bZ;
  assign bidir_port[8] = data_dir[8] ? data_out[8] : 1'bZ;
  assign bidir_port[9] = data_dir[9] ? data_out[9] : 1'bZ;
  assign bidir_port[10] = data_dir[10] ? data_out[10] : 1'bZ;
  assign bidir_port[11] = data_dir[11] ? data_out[11] : 1'bZ;
  assign bidir_port[12] = data_dir[12] ? data_out[12] : 1'bZ;
  assign bidir_port[13] = data_dir[13] ? data_out[13] : 1'bZ;
  assign bidir_port[14] = data_dir[14] ? data_out[14] : 1'bZ;
  assign bidir_port[15] = data_dir[15] ? data_out[15] : 1'bZ;
  assign bidir_port[16] = data_dir[16] ? data_out[16] : 1'bZ;
  assign bidir_port[17] = data_dir[17] ? data_out[17] : 1'bZ;
  assign bidir_port[18] = data_dir[18] ? data_out[18] : 1'bZ;
  assign bidir_port[19] = data_dir[19] ? data_out[19] : 1'bZ;
  assign bidir_port[20] = data_dir[20] ? data_out[20] : 1'bZ;
  assign bidir_port[21] = data_dir[21] ? data_out[21] : 1'bZ;
  assign bidir_port[22] = data_dir[22] ? data_out[22] : 1'bZ;
  assign bidir_port[23] = data_dir[23] ? data_out[23] : 1'bZ;
  assign bidir_port[24] = data_dir[24] ? data_out[24] : 1'bZ;
  assign bidir_port[25] = data_dir[25] ? data_out[25] : 1'bZ;
  assign bidir_port[26] = data_dir[26] ? data_out[26] : 1'bZ;
  assign bidir_port[27] = data_dir[27] ? data_out[27] : 1'bZ;
  assign bidir_port[28] = data_dir[28] ? data_out[28] : 1'bZ;
  assign bidir_port[29] = data_dir[29] ? data_out[29] : 1'bZ;
  assign bidir_port[30] = data_dir[30] ? data_out[30] : 1'bZ;
  assign bidir_port[31] = data_dir[31] ? data_out[31] : 1'bZ;
  assign data_in = bidir_port;
  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          data_dir <= 0;
      else if (chipselect && ~write_n && (address == 1))
          data_dir <= writedata[31 : 0];
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          irq_mask <= 0;
      else if (chipselect && ~write_n && (address == 2))
          irq_mask <= writedata[31 : 0];
    end


  assign irq = |(edge_capture & irq_mask);
  assign edge_capture_wr_strobe = chipselect && ~write_n && (address == 3);
  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[0] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[0])
              edge_capture[0] <= 0;
          else if (edge_detect[0])
              edge_capture[0] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[1] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[1])
              edge_capture[1] <= 0;
          else if (edge_detect[1])
              edge_capture[1] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[2] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[2])
              edge_capture[2] <= 0;
          else if (edge_detect[2])
              edge_capture[2] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[3] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[3])
              edge_capture[3] <= 0;
          else if (edge_detect[3])
              edge_capture[3] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[4] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[4])
              edge_capture[4] <= 0;
          else if (edge_detect[4])
              edge_capture[4] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[5] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[5])
              edge_capture[5] <= 0;
          else if (edge_detect[5])
              edge_capture[5] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[6] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[6])
              edge_capture[6] <= 0;
          else if (edge_detect[6])
              edge_capture[6] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[7] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[7])
              edge_capture[7] <= 0;
          else if (edge_detect[7])
              edge_capture[7] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[8] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[8])
              edge_capture[8] <= 0;
          else if (edge_detect[8])
              edge_capture[8] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[9] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[9])
              edge_capture[9] <= 0;
          else if (edge_detect[9])
              edge_capture[9] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[10] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[10])
              edge_capture[10] <= 0;
          else if (edge_detect[10])
              edge_capture[10] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[11] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[11])
              edge_capture[11] <= 0;
          else if (edge_detect[11])
              edge_capture[11] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[12] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[12])
              edge_capture[12] <= 0;
          else if (edge_detect[12])
              edge_capture[12] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[13] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[13])
              edge_capture[13] <= 0;
          else if (edge_detect[13])
              edge_capture[13] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[14] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[14])
              edge_capture[14] <= 0;
          else if (edge_detect[14])
              edge_capture[14] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[15] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[15])
              edge_capture[15] <= 0;
          else if (edge_detect[15])
              edge_capture[15] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[16] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[16])
              edge_capture[16] <= 0;
          else if (edge_detect[16])
              edge_capture[16] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[17] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[17])
              edge_capture[17] <= 0;
          else if (edge_detect[17])
              edge_capture[17] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[18] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[18])
              edge_capture[18] <= 0;
          else if (edge_detect[18])
              edge_capture[18] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[19] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[19])
              edge_capture[19] <= 0;
          else if (edge_detect[19])
              edge_capture[19] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[20] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[20])
              edge_capture[20] <= 0;
          else if (edge_detect[20])
              edge_capture[20] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[21] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[21])
              edge_capture[21] <= 0;
          else if (edge_detect[21])
              edge_capture[21] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[22] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[22])
              edge_capture[22] <= 0;
          else if (edge_detect[22])
              edge_capture[22] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[23] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[23])
              edge_capture[23] <= 0;
          else if (edge_detect[23])
              edge_capture[23] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[24] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[24])
              edge_capture[24] <= 0;
          else if (edge_detect[24])
              edge_capture[24] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[25] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[25])
              edge_capture[25] <= 0;
          else if (edge_detect[25])
              edge_capture[25] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[26] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[26])
              edge_capture[26] <= 0;
          else if (edge_detect[26])
              edge_capture[26] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[27] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[27])
              edge_capture[27] <= 0;
          else if (edge_detect[27])
              edge_capture[27] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[28] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[28])
              edge_capture[28] <= 0;
          else if (edge_detect[28])
              edge_capture[28] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[29] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[29])
              edge_capture[29] <= 0;
          else if (edge_detect[29])
              edge_capture[29] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[30] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[30])
              edge_capture[30] <= 0;
          else if (edge_detect[30])
              edge_capture[30] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
          edge_capture[31] <= 0;
      else if (clk_en)
          if (edge_capture_wr_strobe && writedata[31])
              edge_capture[31] <= 0;
          else if (edge_detect[31])
              edge_capture[31] <= -1;
    end


  always @(posedge clk or negedge reset_n)
    begin
      if (reset_n == 0)
        begin
          d1_data_in <= 0;
          d2_data_in <= 0;
        end
      else if (clk_en)
        begin
          d1_data_in <= data_in;
          d2_data_in <= d1_data_in;
        end
    end


  assign edge_detect = ~d1_data_in & d2_data_in;

endmodule