can_testbench.v

一个基于can_bus的虚拟程序

  end
endtask



task test_full_fifo_ext;
  begin
    release_rx_buffer;
    $display("\n\n");
    read_receive_buffer;
    fifo_info;

    receive_frame(1, 0, 29'h14d60246, 4'h0, 15'h6f54); // mode, rtr, id, length, crc
    read_receive_buffer;
    fifo_info;
    receive_frame(1, 0, 29'h14d60246, 4'h1, 15'h6d38); // mode, rtr, id, length, crc
    read_receive_buffer;
    fifo_info;
    receive_frame(1, 0, 29'h14d60246, 4'h2, 15'h053e); // mode, rtr, id, length, crc
    fifo_info;
    read_receive_buffer;
    receive_frame(1, 0, 29'h14d60246, 4'h3, 15'h5262); // mode, rtr, id, length, crc
    fifo_info;
    receive_frame(1, 0, 29'h14d60246, 4'h4, 15'h4bba); // mode, rtr, id, length, crc
    fifo_info;
    receive_frame(1, 0, 29'h14d60246, 4'h5, 15'h4d7d); // mode, rtr, id, length, crc
    fifo_info;
    receive_frame(1, 0, 29'h14d60246, 4'h6, 15'h6f40); // mode, rtr, id, length, crc
    fifo_info;
    receive_frame(1, 0, 29'h14d60246, 4'h7, 15'h1730); // mode, rtr, id, length, crc
    fifo_info;
    read_overrun_info(0, 10);

    release_rx_buffer;
    release_rx_buffer;
    fifo_info;
    receive_frame(1, 0, 29'h14d60246, 4'h8, 15'h2f7a); // mode, rtr, id, length, crc
    fifo_info;
    read_overrun_info(0, 15);
    $display("\n\n");

    release_rx_buffer;
    read_receive_buffer;
    fifo_info;

    release_rx_buffer;
    read_receive_buffer;
    fifo_info;

    release_rx_buffer;
    read_receive_buffer;
    fifo_info;

    release_rx_buffer;
    read_receive_buffer;
    fifo_info;

    release_rx_buffer;
    read_receive_buffer;
    fifo_info;

    release_rx_buffer;
    read_receive_buffer;
    fifo_info;

    release_rx_buffer;
    read_receive_buffer;
    fifo_info;

  end
endtask



task initialize_fifo;
  integer i;
  begin
    for (i=0; i<32; i=i+1)
      begin
        can_testbench.i_can_top.i_can_bsp.i_can_fifo.length_info[i] = 0;
        can_testbench.i_can_top.i_can_bsp.i_can_fifo.overrun_info[i] = 0;
      end

    for (i=0; i<64; i=i+1)
      begin
        can_testbench.i_can_top.i_can_bsp.i_can_fifo.fifo[i] = 0;
      end

    $display("(%0t) Fifo initialized", $time);
  end
endtask


task read_overrun_info;
  input [4:0] start_addr;
  input [4:0] end_addr;
  integer i;
  begin
    for (i=start_addr; i<=end_addr; i=i+1)
      begin
        $display("len[0x%0x]=0x%0x", i, can_testbench.i_can_top.i_can_bsp.i_can_fifo.length_info[i]);
        $display("overrun[0x%0x]=0x%0x\n", i, can_testbench.i_can_top.i_can_bsp.i_can_fifo.overrun_info[i]);
      end
  end
endtask


task fifo_info;   // Displaying how many packets and how many bytes are in fifo. Not working when wr_info_pointer is smaller than rd_info_pointer.
  begin
      $display("(%0t) Currently %0d bytes in fifo (%0d packets)", $time, can_testbench.i_can_top.i_can_bsp.i_can_fifo.fifo_cnt, 
      (can_testbench.i_can_top.i_can_bsp.i_can_fifo.wr_info_pointer - can_testbench.i_can_top.i_can_bsp.i_can_fifo.rd_info_pointer));
end
endtask


task read_register;
  input [7:0] reg_addr;

  begin
    @ (posedge wb_clk_i);
    #1; 
    wb_adr_i = reg_addr;
    wb_cyc_i = 1;
    wb_stb_i = 1;
    wb_we_i = 0;
    wait (wb_ack_o);
    $display("(%0t) Reading register [%0d] = 0x%0x", $time, wb_adr_i, wb_dat_o);
    @ (posedge wb_clk_i);
    #1; 
    wb_adr_i = 'hz;
    wb_cyc_i = 0;
    wb_stb_i = 0;
    wb_we_i = 'hz;
  end
endtask


task write_register;
  input [7:0] reg_addr;
  input [7:0] reg_data;

  begin
    @ (posedge wb_clk_i);
    #1; 
    wb_adr_i = reg_addr;
    wb_dat_i = reg_data;
    wb_cyc_i = 1;
    wb_stb_i = 1;
    wb_we_i = 1;
    wait (wb_ack_o);
    @ (posedge wb_clk_i);
    #1; 
    wb_adr_i = 'hz;
    wb_dat_i = 'hz;
    wb_cyc_i = 0;
    wb_stb_i = 0;
    wb_we_i = 'hz;
  end
endtask


task read_receive_buffer;
  integer i;
  begin
    if(`CAN_CLOCK_DIVIDER_MODE)   // Extended mode
      begin
        for (i=8'd16; i<=8'd28; i=i+1)
          read_register(i);
        if (can_testbench.i_can_top.i_can_bsp.i_can_fifo.overrun_info[can_testbench.i_can_top.i_can_bsp.i_can_fifo.rd_info_pointer])
          $display("\nWARNING: This packet was received with overrun.");
      end
    else
      begin
        for (i=8'd20; i<=8'd29; i=i+1)
          read_register(i);
        if (can_testbench.i_can_top.i_can_bsp.i_can_fifo.overrun_info[can_testbench.i_can_top.i_can_bsp.i_can_fifo.rd_info_pointer])
          $display("\nWARNING: This packet was received with overrun.");
      end
  end
endtask


task release_rx_buffer;
  begin
    write_register(8'd1, 8'h4);
    $display("(%0t) Rx buffer released.", $time);
  end
endtask


task tx_request;
  begin
    write_register(8'd1, 8'h1);
    $display("(%0t) Tx requested.", $time);
  end
endtask


task test_synchronization;
  begin
    // Hard synchronization
    #1 rx=0;
    repeat (2*BRP) @ (posedge clk);
    repeat (8*BRP) @ (posedge clk);
    #1 rx=1;
    repeat (10*BRP) @ (posedge clk);
  
    // Resynchronization on time
    #1 rx=0;
    repeat (10*BRP) @ (posedge clk);
    #1 rx=1;
    repeat (10*BRP) @ (posedge clk);
  
    // Resynchronization late
    repeat (BRP) @ (posedge clk);
    repeat (BRP) @ (posedge clk);
    #1 rx=0;
    repeat (10*BRP) @ (posedge clk);
    #1 rx=1;
  
    // Resynchronization early
    repeat (8*BRP) @ (posedge clk);   // two frames too early
    #1 rx=0;
    repeat (10*BRP) @ (posedge clk);
    #1 rx=1;
    repeat (10*BRP) @ (posedge clk);
  end
endtask


task send_bit;
  input bit;
  integer cnt;
  begin
    #1 rx=bit;
    repeat ((`CAN_TIMING1_TSEG1 + `CAN_TIMING1_TSEG2 + 3)*BRP) @ (posedge clk);
  end
endtask


task receive_frame;           // CAN IP core receives frames
  input mode;
  input remote_trans_req;
  input [28:0] id;
  input  [3:0] length;
  input [14:0] crc;

  reg [117:0] data;
  reg         previous_bit;
  reg         stuff;
  reg         tmp;
  reg         arbitration_lost;
  integer     pointer;
  integer     cnt;
  integer     total_bits;
  integer     stuff_cnt;

  begin

    stuff_cnt = 1;
    stuff = 0;

    if(mode)          // Extended format
      data = {id[28:18], 1'b1, 1'b1, id[17:0], remote_trans_req, 2'h0, length};
    else              // Standard format
      data = {id[10:0], remote_trans_req, 1'b0, 1'b0, length};

    if (~remote_trans_req)
      begin
        if(length)    // Send data if length is > 0
          begin
            for (cnt=1; cnt<=(2*length); cnt=cnt+1)  // data   (we are sending nibbles)
              data = {data[113:0], cnt[3:0]};
          end
      end

    // Adding CRC
    data = {data[104:0], crc[14:0]};


    // Calculating pointer that points to the bit that will be send
    if (remote_trans_req)
      begin
        if(mode)          // Extended format
          pointer = 52;
        else              // Standard format
          pointer = 32;
      end
    else
      begin
        if(mode)          // Extended format
          pointer = 52 + 8 * length;
        else              // Standard format
          pointer = 32 + 8 * length;
      end

    // This is how many bits we need to shift
    total_bits = pointer;

    // Waiting until previous msg is finished before sending another one
    wait (~can_testbench.i_can_top.i_can_bsp.error_frame & ~can_testbench.i_can_top.i_can_bsp.rx_inter & ~can_testbench.i_can_top.i_can_bsp.tx_state);
    arbitration_lost = 0;
    
    send_bit(0);                        // SOF
    previous_bit = 0;

    fork 

    begin
      while (~arbitration_lost)
        begin
          for (cnt=0; cnt<=total_bits; cnt=cnt+1)
            begin
              if (stuff_cnt == 5)
                begin
                  stuff_cnt = 1;
                  total_bits = total_bits + 1;
                  stuff = 1;
                  tmp = ~data[pointer+1];
                  send_bit(~data[pointer+1]);
                  previous_bit = ~data[pointer+1];
                end
              else
                begin
                  if (data[pointer] == previous_bit)
                    stuff_cnt <= stuff_cnt + 1;
                  else
                    stuff_cnt <= 1;
                  
                  stuff = 0;
                  tmp = data[pointer];
                  send_bit(data[pointer]);
                  previous_bit = data[pointer];
                  pointer = pointer - 1;
                end
              if (arbitration_lost)
                cnt=total_bits+1;         // Exit the for loop
            end
            arbitration_lost = 1; // At the end we exit the while loop

            // Nothing send after the data (just recessive bit)
            repeat (13) send_bit(1);         // CRC delimiter + ack + ack delimiter + EOF + intermission= 1 + 1 + 1 + 7 + 3
        end
    end

    begin
      while (~arbitration_lost)
        begin
          #1 wait (can_testbench.i_can_top.sample_point);
          if (mode)
            begin
              if (cnt<32 & tmp & (~rx_and_tx))
                begin
                  arbitration_lost = 1;
                  rx = 1;       // Only recessive is send from now on.
                end
            end
          else
            begin
              if (cnt<12 & tmp & (~rx_and_tx))
                begin
                  arbitration_lost = 1;
                  rx = 1;       // Only recessive is send from now on.
                end
            end
        end
    end

    join

  end
endtask



// State machine monitor (btl)
always @ (posedge clk)
begin
  if(can_testbench.i_can_top.i_can_btl.go_sync & can_testbench.i_can_top.i_can_btl.go_seg1 | can_testbench.i_can_top.i_can_btl.go_sync & can_testbench.i_can_top.i_can_btl.go_seg2 | 
     can_testbench.i_can_top.i_can_btl.go_seg1 & can_testbench.i_can_top.i_can_btl.go_seg2)
    begin
      $display("(%0t) ERROR multiple go_sync, go_seg1 or go_seg2 occurance\n\n", $time);
      #1000;
      $stop;
    end

  if(can_testbench.i_can_top.i_can_btl.sync & can_testbench.i_can_top.i_can_btl.seg1 | can_testbench.i_can_top.i_can_btl.sync & can_testbench.i_can_top.i_can_btl.seg2 | 
     can_testbench.i_can_top.i_can_btl.seg1 & can_testbench.i_can_top.i_can_btl.seg2)
    begin
      $display("(%0t) ERROR multiple sync, seg1 or seg2 occurance\n\n", $time);
      #1000;
      $stop;
    end
end

/* stuff_error monitor (bsp)
always @ (posedge clk)
begin
  if(can_testbench.i_can_top.i_can_bsp.stuff_error)
    begin
      $display("\n\n(%0t) Stuff error occured in can_bsp.v file\n\n", $time);
      $stop;                                      After everything is finished add another condition (something like & (~idle)) and enable stop
    end
end
*/

//
// CRC monitor (used until proper CRC generation is used in testbench
always @ (posedge clk)
begin
  if (can_testbench.i_can_top.i_can_bsp.crc_err)
    $display("Calculated crc = 0x%0x, crc_in = 0x%0x", can_testbench.i_can_top.i_can_bsp.calculated_crc, can_testbench.i_can_top.i_can_bsp.crc_in);
end
//




/*
// overrun monitor
always @ (posedge clk)
begin
  if (can_testbench.i_can_top.i_can_bsp.i_can_fifo.wr & can_testbench.i_can_top.i_can_bsp.i_can_fifo.fifo_full)
    $display("(%0t)overrun", $time);
end
*/


// form error monitor
always @ (posedge clk)
begin
  if (can_testbench.i_can_top.i_can_bsp.form_err)
    $display("\n\n(%0t) ERROR: form_error\n\n", $time);
end
//


endmodule