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/*-----------------------------------------------------------------
|           Ethernet MAC Testbench                                  |
|                                                                   |
------------------------------------------------------------------*/
 
/*-----------------------------------------------------------------\
|  DESCRIPTION:                                                    |
|  tb_tasks.v:  Testbench tasks included in th_top.v               |
|                                                                  |
|  Instantiated modules: none                                      |
|  Included files: none                                            |
\-----------------------------------------------------------------*/
 
 /*-------------------------------------------------------------\
 |                                                              |
 |      Tasks to set port and MAC parameters such as            |
 |      preamble, collision parameters, etc.                    |
 |                                                              |
 \-------------------------------------------------------------*/
 
task init_port;
      input [2:0] speed;
   input [2:0]     MII_type;
   input duplex_status;
   input IFG_length;
   integer IFG_length;
 
   begin
      if ((port_mii_type != 3'b111) &&
          (port_mii_type != MII_type))
       begin
          $write("testbench_init_port:  MII type_new cannot be changed once set\n");
          if (`TERMINATE_ON_TASK_ERRORS)
           $finish;
       end // if ((port_mii_type != 3'b111) &&...
      else
       begin
          port_mii_type = MII_type;
          port_duplex_status = duplex_status;
          port_speed = speed;
          port_min_ifg = IFG_length;
 
          // initialize port parameters to their default values
          port_idle_count = 0; // number of idle bits transmitted before preamble
          preamble_length = 64; // 64-bit preamble, including SFD
          preamble_reg = {64'd0,
                          64'hd555_5555_5555_5555}; // preamble pattern
 
          dribble_bit_count = 0; //bits buffered in PHY when carrier goes down
          carrier_override = 0; // Do not force carrier
          frame_extend_bit_count = 0; // Do not send additional bits after packet data
          frame_extend_reg = 32'd0; // Pattern of additional bits
          ignore_rcv_pause = 0; // handle received PAUSE frames normally
          pause_increment = 0; // Do not change received PAUSE parameter
          collision_detection_delay = 0;  // collision detection delay in PHY
          force_collision = 0; // Do not force collisions
          jam_length = 32; // length of jamming pattern in bits
 
          force_collision_delay = 32'd0;
 
          packet_seq_no = 32'd0; // Running sequence number for port
 
          // activate the proper MII interface
          case (port_mii_type)
            0: // Reduced MII
             begin
                RMII_port_tx_enable = 1;
                RMII_port_rx_enable = 1;
             end // case: 0
            1: // Full MII
             begin
                MII_port_tx_enable = 1;
                MII_port_rx_enable = 1;
             end // case: 1
            2: // Gigabit MII
             begin
                GMII_port_tx_enable = 1;
                GMII_port_rx_enable = 1;
             end // case: 2
            3: // Serial MII
             begin
                SMII_port_tx_enable = 1;
                SMII_port_rx_enable = 1;
             end // case: 3
            4: // custom interface
             begin
                custom_tx_enable = 1;
                custom_rx_enable = 1;
             end // case: 4
            5: // Gigabit 10-bit SERDES interface
             begin
                SERDES_tx_enable = 1;
                SERDES_rx_enable = 1;
             end // case: 0
            default:
             begin
                $write("testbench_init_port: MII type_new %0d not supported",
                       port_mii_type);
                if (`TERMINATE_ON_PARAM_ERRORS)
                 $finish;
             end // case: default
          endcase // case(port_mii_type)
       end // else: !if((port_mii_type != 3'b111) &&...
   end
endtask // testbench_init_port
 
task set_idle_count;
 
   // Sets number if idle bits sent before preamble
   input bit_count;
   integer bit_count;
   begin
      port_idle_count = bit_count;
   end
endtask // set_idle_count
 
task set_preamble;
 
   // Sets preamble length and pattern
   input length;
   input [127:0] pattern;
   integer length;
   begin
      preamble_length = length;
      preamble_reg = pattern;
   end
endtask // set_preamble
 
task set_dribble_bit_count;
   // Sets number of bits buffered in the PHY when carrier sense is deasserted
   input count;
   integer count;
   begin
      dribble_bit_count = count;
   end
endtask // set_dribble_bit_count
 
task set_frame_extension_bits;
   // Sets count of bits added to the frame to generate alignment error
   input count;
   input [31:0] pattern;
   integer count;
   begin
      frame_extend_bit_count = count;
      frame_extend_reg = pattern;
   end
endtask // set_frame_extension_bits
 
task set_carrier_sense;
   input value;
   begin
      carrier_override = value;
   end
endtask // set_carrier_sense
 
task set_pause_options;
   // Set option for handling of received PAUSE frames
   input option, increment;
   integer option, increment;
   begin
      case(option)
        1: // add user-supplied increment to pause parameter received
         begin
            ignore_rcv_pause = 0;
            pause_increment = increment;
         end // case: 1
        2: // ignore received pause frames
         begin
            ignore_rcv_pause = 1;
         end // case: 2
        default: // handle pause frames normally
         begin
            ignore_rcv_pause = 0;
            pause_increment = 0;
         end // case: 0
      endcase // case(option)
   end
endtask // set_pause_options
 
task set_collision_detect_delay;
   // Set delay between occurrence of collision and
   // processing by the testbench
   // value in nanoseconds
   input delay;
   integer delay;
   begin
      collision_detection_delay = delay;
   end
endtask // set_collision_detect_delay
 
task set_jam_length;
   // Set length of jamming pattern sent in response to collision event
   input length;
   integer length;
   begin
      jam_length = length;
   end
endtask // set_jam_length
 
 
task set_collision_backoff;
   // Set collision backoff in number of slots
   // collision_count
   // index = index of collision whose parameters are to be set
   // slots = number of slots to backoff
   // flag = 0: back off deterministically by constant number of slots
   //      = 1: back off by random number of slots between 0 and slots-1
   //      = 2: end backoff and reset collision counter
   input index, slots, flag;
   integer index, slots, flag;
   begin
      if ((index > 0) && (index <= `MAX_COLLISIONS)) // check validity of index
       begin
          case(flag)
            0: begin // deterministic backoff
               backoff_slots[index] = slots;
               backoff_type[index] = 0;
            end // case: 0
            1: begin // random backoff
               backoff_slots[index] = slots;
               backoff_type[index] = 1;
            end // case: 1
            default: begin // set collision limit
               collision_limit = index;
            end // case: default
          endcase // case(flag)
       end // if ((index > 0) && (index <= `MAX_COLLISIONS))
      else
       if ((index == `MAX_COLLISIONS) && (flag >= 2)) // set collision limit
        collision_limit = index;
   end
endtask // set_collision_backoff
 
 /*-------------------------------------------------------------\
 |                                                              |
 |      Tasks to set flow parameters such as                    |
 |      packet size and header fields                           |
 |                                                              |
 \-------------------------------------------------------------*/
 
task set_flow_type;
// Sets flow type_new for the packet sequence to be generated
   input [7:0]  type_new;
   begin
      flow_type = type_new;
   end
endtask // set_flow_type
 
task set_L2_protocol;
   // sets L2 protocol at ingress
   input type_new;
   integer type_new;
   begin
      L2_protocol_type = type_new[7:0];
      L2_custom_header_enable = 0; // disable custom header
   end
endtask // testbench_set_L2_protocol
 
task set_L2_source_address;
   // sets source MAC address for transmitted frames
   input type_new;
   input [47:0] mac_min, mac_max, mac_incr;
   integer type_new;
 
   reg [31:0] x, y;
   reg [47:0] mac_random;
 
   begin
      L2_src_mac_min = mac_min;
      L2_src_mac_max = mac_max;
      L2_src_mac_incr = mac_incr;
      L2_src_mac_option = type_new[1:0];
      L2_custom_header_enable = 0; // disable custom header
 
      // set current MAC address for packet sequence
      case (L2_src_mac_option)
        0: // constant
         current_src_mac = L2_src_mac_min;
        1: // incremental
         if (L2_src_mac_incr[47] == 0)
          current_src_mac = L2_src_mac_min;
         else
          current_src_mac = L2_src_mac_max;
        2: // random
         begin
            x = $random();
            y = $random();
            mac_random = {x[15:0], y[31:0]};
            if (L2_src_mac_min != L2_src_mac_max)
             current_src_mac = L2_src_mac_min +
                                  (mac_random % (L2_src_mac_max -
                                                 L2_src_mac_min));
            else
             current_src_mac = L2_src_mac_min;
         end // case: 2
      endcase // case(L2_src_mac_option)
   end
endtask // set_L2_source_address
 
task set_L2_destination_address;
   // sets destination MAC address for transmitted frames
   input type_new;
   input [47:0] mac_min, mac_max, mac_incr;
   integer type_new;
 
   reg [31:0] x, y;
   reg [47:0] mac_random;
   begin
      L2_dstn_mac_min = mac_min;
      L2_dstn_mac_max = mac_max;
      L2_dstn_mac_incr = mac_incr;
      L2_dstn_mac_option = type_new[1:0];
      L2_custom_header_enable = 0; // disable custom header
 
      // Set current destination MAC for packet sequence
      case (L2_dstn_mac_option)
        0: // constant
         current_dstn_mac = L2_dstn_mac_min;
        1: // incremental
         if (L2_dstn_mac_incr[47] == 0)
          current_dstn_mac = L2_dstn_mac_min;
         else
          current_dstn_mac = L2_dstn_mac_max;
        2: // random
         begin
            x = $random();
            y = $random();
            mac_random = {x[15:0], y[31:0]};
            if (L2_dstn_mac_min != L2_dstn_mac_max)
             current_dstn_mac = L2_dstn_mac_min +
                                   (mac_random % (L2_dstn_mac_max -
                                                  L2_dstn_mac_min));
            else
             current_dstn_mac = L2_dstn_mac_min;
         end // case: 2
      endcase // case(L2_dstn_mac_option)
   end
endtask // set_L2_destination_address
 
task set_L2_VLAN_TCI;
   // sets VLAN TCI of transmitted frames
   input type_new;
   input [15:0] min_TCI, max_TCI, increment;
   integer type_new;
 
   reg [31:0] x;
   begin
      L2_VLAN_TCI_min = min_TCI;
      L2_VLAN_TCI_max = max_TCI;
      L2_VLAN_TCI_incr = increment;
      L2_VLAN_TCI_option = type_new[1:0];
      L2_custom_header_enable = 0; // disable custom header
 
      // set current VLAN TCI for packet sequence
      case (L2_VLAN_TCI_option)
        0: // constant
         current_VLAN_TCI = L2_VLAN_TCI_min;
        1: // incremental
         if (L2_VLAN_TCI_incr[15] == 0)
          current_VLAN_TCI = L2_VLAN_TCI_min;
         else
          current_VLAN_TCI = L2_VLAN_TCI_max;
        2: // random
         begin
            x = $random();
            if (L2_VLAN_TCI_max != L2_VLAN_TCI_min)
             current_VLAN_TCI = L2_VLAN_TCI_min +
                                   (x % (L2_VLAN_TCI_max -
                                         L2_VLAN_TCI_min));
            else
             current_VLAN_TCI = L2_VLAN_TCI_min;
         end // case: 2
      endcase // case(L2_VLAN_TCI_option)
   end
endtask // set_L2_VLAN_TCI
 
task set_L2_VLAN_TPID;
   // sets VLAN TPID field
   input [15:0] TPID;
   begin
      L2_VLAN_TPID = TPID;
      L2_custom_header_enable = 0; // disable custom header
   end
endtask
 
task set_L2_frame_size;
   // sets size of transmitted frames
   input type_new, min_size, max_size, increment;
   integer type_new, min_size, max_size, increment;
 
   reg [31:0] x;
   begin
      L2_frame_size_option = type_new[1:0];
      L2_frame_size_min = min_size;
      L2_frame_size_max = max_size;
      L2_frame_size_incr = increment;
 
      // set current packet size parameter
      case (L2_frame_size_option)
        0: // constant
         current_pkt_size = L2_frame_size_min;
        1: // incremental
         if (increment >= 0)
          current_pkt_size = L2_frame_size_min;
         else
          current_pkt_size = L2_frame_size_max;
        2: // $random
         begin
            x = $random();
            if (L2_frame_size_max != L2_frame_size_min)
             current_pkt_size = L2_frame_size_min +
                                     (x % (L2_frame_size_max - L2_frame_size_min));
            else
             current_pkt_size = L2_frame_size_min;
         end // case: 2
      endcase // case(L2_frame_size_option)
   end
endtask
 
task set_L2_type_field;
   // sets 16-bit type_new field for L2 Ethernet flows
   input [15:0] type_new;
   begin
      L2_type_field = type_new;
   end
endtask // testbench_set_L2_type_field
 
task set_LLC_header;
   // sets LLC and SNAP headers for transmitted frames
   // default is aa_aa_03_00_00_00_08_00 hex
   input header_length;
   input [`MAX_HEADER_SIZE*8-1: 0] header;
      integer header_length;
   begin
      L2_LLC_header = header;
      L2_LLC_header_length = header_length;
      L2_LLC_header_enable = 1;
   end
endtask // testbench_set_LLC_header
 
task set_L2_custom_header;
   // sets a user-defined L2 header
   input header_length;
   input [`MAX_HEADER_SIZE*8-1: 0] header;
   integer header_length;
 
   begin
      if (header_length == 0) //disable user-defined L2 header
       L2_custom_header_enable = 0;
      else
       begin
          L2_custom_header_enable = 1;
          L2_custom_header = header;
          L2_custom_header_length = header_length;
       end // else: !if(header_length == 0)
   end
endtask // testbench_set_L2_custom_header
 
task set_L3_protocol;
   // sets L3 protocol
   input protocol;
   integer protocol;
   begin
      L3_protocol_type = protocol[7:0];
   end
endtask
 
task set_IP_header;
   // sets IP header fields
   input [31:0] src_addr, dstn_addr;
   input [7:0] service_type;
   input [15:0] sequence_number;
   input [2:0] flags;
   input [12:0] fragment_offset;
   input [7:0] ttl;
   input [7:0] protocol;
   begin
      L3_src_address = src_addr;
      L3_dstn_address = dstn_addr;
      L3_sequence_number = sequence_number;
      IP_flags = flags;
      IP_fragment_offset = fragment_offset;
      L3_TTL = ttl;
      IP_protocol_field = protocol;
      IP_service_type = service_type;
   end // else: !if((flow_id < 0) || (flow_id > NFLOWS))
endtask // testbench_set_L3_IP_header
 
task set_IP_extension_header;
   // sets IP extension header
   input header_length;
   input [`IP_EXTENSION_HEADER_SIZE*8-1: 0] header;
   integer header_length;
   begin
      IP_ext_header = header;
      IP_ext_header_length = header_length;
   end // else: !if((flow_id < 0) || (flow_id > NFLOWS))
endtask // set_IP_extension_header
 
task set_L3_custom_header;
   // sets a user-defined L2 header
   input header_length;
   input [`MAX_HEADER_SIZE*8-1: 0] header;
   integer header_length;
   begin
      if (header_length == 0) //disable user-defined LLC header
       L3_custom_header_enable = 0;
      else
       begin
          L3_custom_header_enable = 1;
          L3_custom_header = header;
          L3_custom_header_length = header_length;
       end // else: !if(header_length == 0)
   end
endtask // set_L3_custom_header
 
task set_L4_protocol;
   // sets L4 protocol
   input protocol;
   integer protocol;
   begin
      L4_protocol_type = protocol[7:0];
   end
endtask
 
task set_TCP_port_numbers;
   // sets TCP header fields
   input src_port, dstn_port;
   integer src_port, dstn_port;
   begin
      L4_src_port = src_port;
      L4_dstn_port = dstn_port;
   end
endtask // set_TCP_header
 
task set_TCP_sequence_number;
   input sequence_number;
   integer sequence_number;
   begin
      L4_sequence_number = sequence_number;
   end
endtask // set_TCP_sequence_number
 
task set_TCP_header_fields;
   // sets other fields in TCP header
   input [31:0] ack_number;
   input [5:0] flags;
   input [15:0] urgent_pointer;
   input [15:0] window_size;
   begin
      L4_ack_number = ack_number;
      TCP_flags = flags;
      TCP_urgent_pointer = urgent_pointer;
      TCP_window_size = window_size;
   end
endtask
 
task set_UDP_port_numbers;
   // sets UDP header fields
   input src_port, dstn_port;
   integer src_port, dstn_port;
   begin
      L4_src_port = src_port;
      L4_dstn_port = dstn_port;
   end
endtask // 
 
task set_L4_custom_header;
   // sets a user-defined L4 header
   input header_length;
   input [`MAX_HEADER_SIZE*8-1: 0] header;
   integer header_length;
   begin
      if (header_length == 0) //disable user-defined LLC header
       L4_custom_header_enable = 0;
      else
       begin
          L4_custom_header_enable = 1;
          L4_custom_header = header;
          L4_custom_header_length = header_length;
       end // else: !if(header_length == 0)
   end
endtask // testbench_set_L4_custom_header
 
task set_payload_data;
   // sets payload of transmitted packets from user-supplied buffer
   input length;
   input [`MAX_PKT_SIZE*8-1: 0] payload;
   integer length;
   begin
      user_payload = payload;
      payload_length = length;
      payload_option = 2'd3; // enable user_defined payload
   end
endtask // set_payload
 
task set_payload_type;
   input option, length, start;
   integer option, length, start;
   begin
      payload_option = option[1:0]; // defines random, increasing, or decreasing sequence
      payload_length = length;
      payload_start = start;
   end
endtask // set_payload_option
 
task set_crc_option;
   // Sets option for L2 CRC generation
   input option, value;
   integer option, value;
   begin
      flowrec_crc_option = option[1:0];
      flowrec_user_crc = value;
   end
endtask // set_crc_option
 
task set_user_crc_option;
   // Sets option for CRC generation for user-supplied frames,
   // including PAUSE frames
   input option, value;
   integer option, value;
   begin
      user_crc_option = option[1:0];
      user_crc_value = value;
   end
endtask // set_user_crc_option
 
task set_L3_checksum_option;
   // Sets option for L3 checksum generation
   input option;
   input [15:0]  value;
   integer option;
   begin
      L3_checksum_option = option;
      L3_user_checksum = value;
   end
endtask // set_L3_checksum_option
 
task set_L4_checksum_option;
   // Sets option for L4 checksum generation
   input option;
   input [15:0] value;
   integer option;
   begin
      L4_checksum_option = option;
      L4_user_checksum = value;
   end
endtask // set_L4_checksum_option
 
task enable_sequence_number;
   input flag, offset;
   integer offset;
   begin
      seqno_enable = flag;
      if (seqno_enable)
       seq_number_offset = offset;
   end
endtask // enable_sequence_number
 
task enable_timestamp;
   input flag, offset;
   integer offset;
   begin
      timestamp_enable = flag;
      if (timestamp_enable)
       timestamp_offset = offset;
   end
endtask // enable_timestamp
 
task set_default_header_parameters;
   begin
      // initialize default header parameters
 
      L2_custom_header_enable = 0; // do not use custom headers
      L3_custom_header_enable = 0;
      IP_ext_header_length = 0; // No IP extension header
      L4_custom_header_enable = 0;
      payload_option = 0; // generate payload as increasing sequence of byte_news
 
      L2_protocol_type = 2; // default = 802.3 with no VLAN tagging
      L2_src_mac_option = 2'b00;    // Fixed source MAC
      L2_src_mac_min = 48'h01_02_03_04_05_06; // source MAC address
      L2_dstn_mac_option = 2'b00;    // Fixed destination MAC
      if (flow_type == 1) // Layer-2 broadcast
       L2_dstn_mac_min = 48'hff_ff_ff_ff_ff_ff; // destination MAC address
      else
       L2_dstn_mac_min = 48'h06_05_04_03_02_01;
      L2_type_field = `DEFAULT_L2_TYPE;   // Default type_new field for Ethernet frames
      L2_VLAN_TCI_option = 2'b00; // Fixed VLAN tag
      L2_VLAN_TCI_min = 0;        // Null VLAN tag
 
      L2_VLAN_TPID = `DEFAULT_VLAN_TPID; // default 802.1Q TPID = 8100 hex
 
      L2_frame_size_option = 2'b00; // constant size frames
      L2_frame_size_min = 64;       // 64-byte_new frames
      flowrec_crc_option = 0;  // append good CRC
 
      // set current packet parameters
      current_pkt_size = L2_frame_size_min;
      current_src_mac = L2_src_mac_min;
      current_dstn_mac = L2_dstn_mac_min;
      current_VLAN_TCI = L2_VLAN_TCI_min;
 
      // Set default LLC header (for IP)
      L2_LLC_header_length = 8;  // 3-byte_new LLC + 5-byte_new SNAP
      L2_LLC_header = {192'd0, 64'haa_aa_03_00_00_00_08_00};
 
      // Set default L3 header parameters
      L3_protocol_type = 4;  // default = IP v4
      L3_checksum_option = 0; // transmit good checksum
 
      L3_src_address =  32'h80_00_00_01; // IP source address
      L3_dstn_address = 32'h81_00_00_01; // IP destination address
      L3_TTL = 1;                        // IP time-to-live field
      L3_sequence_number = 16'd0;
      IP_flags = 3'd0;
      IP_fragment_offset = 0;
      L3_TTL = 1;
      IP_protocol_field = 8'd0;
      IP_service_type = 8'd0;
 
      // Set default L4 header parameters
      L4_protocol_type = 0;  // default = TCP
      L4_src_port = 0;       // TCP source port
      L4_dstn_port = 0;      // TCP destination port
      L4_checksum_option = 0; // enable good L4 checksum
      L4_sequence_number = 0;
      L4_ack_number = 0;    // TCP sequence and ack numbers
      TCP_flags = 6'b000000; // Flags in TCP header;
      TCP_urgent_pointer = 0; // Urgent pointer in TCP header
      TCP_window_size = 0;   // TCP advertised window
 
      payload_length = `MAX_PKT_SIZE; // set default max payload size 
      payload_option = 2'b00; // payload = increasing sequence of byte_news
      payload_start = 0; // starting at 0
   end
 
endtask // set_default_header_parameters
 
task print_packet_parameters;
   // print current parameter settings to console and file 
 
   integer int1, int2, int3, int4, int5;
   integer i, j;
   reg [`MAX_HEADER_SIZE*8-1:0] header;
   reg [47:0] mac_addr1;
   reg [7:0] byte_new;
 
   begin
      int1 = flow_type;
      $write("flow type_new = %0d ", int1);
      $fwrite(outfile, "flow type_new = %0d ", int1);
      case (int1)
        0:
         begin
            $write("(L2 unicast)\n");
            $fwrite(outfile, "(L2 unicast)\n");
         end // case: 0
        1:
         begin
            $write("(L2 broadcast)\n");
            $fwrite(outfile, "(L2 broadcast)\n");
         end // case: 1
        2:
         begin
            $write("(L2 multicast)\n");
            $fwrite(outfile, "(L2 multicast)\n");
         end // case: 2
        3:
         begin
            $write("(L3 unicast)\n");
            $fwrite(outfile, "(L3 unicast)\n");
         end // case: 3
        4:
         begin
            $write("(L3 multicast)\n");
            $fwrite(outfile, "(L3 multicast)\n");
         end // case: 4
        5:
         begin
            $write("(L4 unicast)\n");
            $fwrite(outfile, "(L4 unicast)\n");
         end // case: 5
        6:
         begin
            $write("(L4 multicast)\n");
            $fwrite(outfile, "(L4 multicast)\n");
         end // case: 6
        default:
         begin
            $write("(unknown)\n");
            $fwrite(outfile, "(unknown)\n");
         end // case: default
      endcase // case(int1)
 
      if (!L2_custom_header_enable)
       begin
          int1 = L2_protocol_type;
          $write("L2 protocol = %0d ", int1);
          $fwrite(outfile, "L2 protocol = %0d ", int1);
          case (int1)
            0:
             begin
                $write("(untagged Ethernet)\n");
                $fwrite(outfile, "(untagged Ethernet)\n");
             end // case: 0
            1:
             begin
                $write("(tagged Ethernet)\n");
                $fwrite(outfile, "(tagged Ethernet)\n");
             end
            2:
             begin
                $write("(untagged 802.3)\n");
                $fwrite(outfile, "(untagged 802.3)\n");
             end // case: 2
            3:
             begin
                $write("(tagged 802.3)\n");
                $fwrite(outfile, "(tagged 802.3)\n");
             end // case: 3
            4:
             begin
                $write("(802.1d BPDU)\n");
                $fwrite(outfile, "(802.1d BPDU)\n");
             end // case: 4
            default:
             begin
                $write("(unknown)\n");
                $fwrite(outfile, "(unknown)\n");
             end // case: default
          endcase // case(int1)
 
          int1 = L2_frame_size_option;
          $write("L2 frame size option = %0d ", int1);
          $fwrite(outfile, "L2 frame size option = %0d ", int1);
          case (int1)
            0:
             begin
                int2 = L2_frame_size_min;
                $write("(constant), frame size = %0d\n", int2);
                $fwrite(outfile, "(constant), frame size = %0d\n", int2);
             end // case: 0
            1:
             begin
                int2 = L2_frame_size_min;
                int3 = L2_frame_size_max;
                int4 = current_pkt_size;
                int5 = L2_frame_size_incr;
                $write("(incremental), current size = %0d, min = %0d, max = %0d, increment = %0d\n",
                       int4, int2, int3, int5);
                $fwrite(outfile,
                        "(incremental), current size = %0d, min = %0d, max = %0d, increment = %0d\n",
                        int4, int2, int3, int5);
             end // case: 1
            2:
             begin
                int2 = L2_frame_size_min;
                int3 = L2_frame_size_max;
                $write("(random), min = %0d, max = %0d\n",
                       int2, int3);
                $fwrite(outfile, "(random), min = %0d, max = %0d\n",
                        int2, int3);
             end // case: 2
            default:
             begin
                $write("\n");
                $fwrite(outfile, "\n");
             end // case: default
          endcase // case(int1)
 
          // print source MAC
          int1 = L2_src_mac_option;
          $write("Source MAC option = %0d ", int1);
          $fwrite(outfile, "Source MAC option = %0d ", int1);
          case (int1)
            0:
             begin
                mac_addr1 = L2_src_mac_min;
                $write("(constant), MAC addr = ");
                $fwrite(outfile, "(constant), MAC addr = ");
                $write("%h:%h:%h:%h:%h:%h\n",
                       mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                       mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
                $fwrite(outfile, "%h:%h:%h:%h:%h:%h\n",
                        mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                        mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
             end // case: 0
            1:
             begin
                $write("(incremental), current = ");
                $fwrite(outfile, "(incremental), current = ");
                mac_addr1 = current_src_mac;
                $write("%h:%h:%h:%h:%h:%h\n",
                       mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                       mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
                $fwrite(outfile, "%h:%h:%h:%h:%h:%h\n",
                        mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                        mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
                $write("min = ");
                $fwrite(outfile, "min = ");
                mac_addr1 = L2_src_mac_min;
                $write("%h:%h:%h:%h:%h:%h",
                       mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                       mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
                $fwrite(outfile, "%h:%h:%h:%h:%h:%h",
                        mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                        mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
                $write(", max = ");
                $fwrite(outfile, ", max = ");
                mac_addr1 = L2_src_mac_max;
                $write("%h:%h:%h:%h:%h:%h",
                       mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                       mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
                $fwrite(outfile, "%h:%h:%h:%h:%h:%h",
                        mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                        mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
                $write(", incr = ");
                $fwrite(outfile, ", incr = ");
                mac_addr1 = L2_src_mac_incr;
                $write("%h:%h:%h:%h:%h:%h\n",
                       mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                       mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
                $fwrite(outfile, "%h:%h:%h:%h:%h:%h\n",
                        mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                        mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
             end // case: 1
            2:
             begin
                $write("(random), min = ");
                $fwrite(outfile, "(random), min = ");
                mac_addr1 = L2_src_mac_min;
                $write("%h:%h:%h:%h:%h:%h",
                       mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                       mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
                $fwrite(outfile, "%h:%h:%h:%h:%h:%h",
                        mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                        mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
                $write(", max = ");
                $fwrite(outfile, ", max = ");
                mac_addr1 = L2_src_mac_max;
                $write("%h:%h:%h:%h:%h:%h\n",
                       mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                       mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
                $fwrite(outfile, "%h:%h:%h:%h:%h:%h\n",
                        mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                        mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
             end // case: 2
            default:
             begin
                $write("\n");
                $fwrite(outfile, "\n");
             end // case: default
          endcase // case(int1)
 
          // print destination MAC
          int1 = L2_dstn_mac_option;
          $write("Dest MAC option = %0d ", int1);
          $fwrite(outfile, "Dest MAC option = %0d ", int1);
          case (int1)
            0:
             begin
                mac_addr1 = L2_dstn_mac_min;
                $write("(constant), MAC addr = ");
                $fwrite(outfile, "(constant), MAC addr = ");
                $write("%h:%h:%h:%h:%h:%h\n",
                       mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                       mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
                $fwrite(outfile, "%h:%h:%h:%h:%h:%h\n",
                        mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                        mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
             end // case: 0
            1:
             begin
                $write("(incremental), current = ");
                $fwrite(outfile, "(incremental), current = ");
                mac_addr1 = current_dstn_mac;
                $write("%h:%h:%h:%h:%h:%h\n",
                       mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                       mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
                $fwrite(outfile, "%h:%h:%h:%h:%h:%h\n",
                        mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                        mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
                $write("min = ");
                $fwrite(outfile, "min = ");
                mac_addr1 = L2_dstn_mac_min;
                $write("%h:%h:%h:%h:%h:%h",
                       mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                       mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
                $fwrite(outfile, "%h:%h:%h:%h:%h:%h",
                        mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                        mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
                $write(", max = ");
                $fwrite(outfile, ", max = ");
                mac_addr1 = L2_dstn_mac_max;
                $write("%h:%h:%h:%h:%h:%h",
                       mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                       mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
                $fwrite(outfile, "%h:%h:%h:%h:%h:%h",
                        mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                        mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
                $write(", incr = ");
                $fwrite(outfile, ", incr = ");
                mac_addr1 = L2_dstn_mac_incr;
                $write("%h:%h:%h:%h:%h:%h\n",
                       mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                       mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
                $fwrite(outfile, "%h:%h:%h:%h:%h:%h\n",
                        mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                        mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
             end // case: 1
            2:
             begin
                $write("(random), min = ");
                $fwrite(outfile, "(random), min = ");
                mac_addr1 = L2_dstn_mac_min;
                $write("%h:%h:%h:%h:%h:%h",
                       mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                       mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
                $fwrite(outfile, "%h:%h:%h:%h:%h:%h",
                        mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                        mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
                $write(", max = ");
                $fwrite(outfile, ", max = ");
                mac_addr1 = L2_dstn_mac_max;
                $write("%h:%h:%h:%h:%h:%h\n",
                       mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                       mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
                $fwrite(outfile, "%h:%h:%h:%h:%h:%h\n",
                        mac_addr1[47:40], mac_addr1[39:32], mac_addr1[31:24],
                        mac_addr1[23:16], mac_addr1[15: 8], mac_addr1[ 7: 0]);
             end // case: 2
            default:
             begin
                $write("\n");
                $fwrite(outfile, "\n");
             end // case: default
          endcase // case(int1)
 
          // print VLAN TCI
          int1 = L2_protocol_type;
          if ((int1 == 1) || (int1 == 3)) // tagged frames
           begin
              int1 = L2_VLAN_TCI_option;
              $write("L2 VLAN TCI option = %0d ", int1);
              $fwrite(outfile, "L2 VLAN TCI option = %0d ", int1);
              case (int1)
                0:
                 begin
                    int2 = L2_VLAN_TCI_min;
                    $write("(constant), TCI = %h\n", int2[15:0]);
                    $fwrite(outfile, "(constant), TCI = %h\n", int2[15:0]);
                 end // case: 0
                1:
                 begin
                    int2 = L2_VLAN_TCI_min;
                    int3 = L2_VLAN_TCI_max;
                    int4 = current_VLAN_TCI;
                    int5 = L2_VLAN_TCI_incr;
                    $write("(incremental), current = %h, min = %h, max = %h, increment = %h\n",
                           int4[15:0], int2[15:0], int3[15:0], int5[15:0]);
                    $fwrite(outfile,
                            "(incremental), current = %h, min = %h, max = %h, increment = %h\n",
                            int4[15:0], int2[15:0], int3[15:0], int5[15:0]);
                 end // case: 1
                2:
                 begin
                    int2 = L2_VLAN_TCI_min;
                    int3 = L2_VLAN_TCI_max;
                    $write("(random), min = %h, max = %h\n",
                           int2[15:0], int3[15:0]);
                    $fwrite(outfile, "(random), min = %h, max = %h\n",
                            int2[15:0], int3[15:0]);
                 end // case: 2
                default:
                 begin
                    $write("\n");
                    $fwrite(outfile, "\n");
                 end // case: default
              endcase // case(int1)
           end // if ((int1 == 1) || (int1 == 3))
 
          // print type_new field
          int1 = L2_protocol_type;
          if ((int1 == 0) || (int1 == 1)) // Only for Ethernet frames
           begin
              int1 = L2_type_field;
              $write("L2 type_new = %h\n", int1[15:0]);
              $fwrite(outfile, "L2 type_new = %h\n", int1[15:0]);
           end // if ((int1 == 0) || (int1 == 1))
 
          // print L2 LLC header
          if ((L2_LLC_header_enable) &&
              (L2_LLC_header_length != 0))
           begin
              $write("LLC header = ");
              $fwrite(outfile, "LLC header = ");
              header = L2_LLC_header;
              for (i= L2_LLC_header_length-1; i >= 0;
                   i = i-1)
               begin
                  for (j=0; j < 8; j= j+1)
                   byte_new[j] = header[i*8 +j];
                  $write("%h ", byte_new[7:0]);
                  $fwrite(outfile,"%h ", byte_new[7:0]);
               end // for (i = L2_LLC_header_length;...
              $write("\n");
              $fwrite(outfile, "\n");
           end // if ((L2_LLC_header_enable) &&...
       end // if (!L2_custom_header_enable)
      else
       // print L2 custom header
       if (L2_custom_header_length != 0)
        begin
           $write("L2 custom header = ");
           $fwrite(outfile, "L2 custom header = ");
           header = L2_custom_header;
           for (i = L2_custom_header_length -1;
                i >= 0; i = i-1)
            begin
               for (j=0; j < 8; j= j+1)
                byte_new[j] = header[i*8 +j];
               $write("%h ", byte_new[7:0]);
               $fwrite(outfile,"%h ", byte_new[7:0]);
            end // for (i = L2_custom_header_length;...
           $write("\n");
           $fwrite(outfile, "\n");
        end // if (L2_custom_header_length != 0)
 
      // print IFG
      $write("Current IFG = %0d\n", current_ifg);
      $fwrite(outfile,
              "Current IFG = %0d\n", current_ifg);
 
      // print CRC option
      $write("L2 CRC option = %0d ", flowrec_crc_option);
      $fwrite(outfile,
              "L2 CRC option = %0d ", flowrec_crc_option);
      case (flowrec_crc_option)
        0:
         begin
            $write("(normal CRC)\n");
            $fwrite(outfile, "(normal CRC)\n");
         end // case: 0
        1:
         begin
            $write("(bad CRC)\n");
            $fwrite(outfile, "(bad CRC)\n");
         end // case: 1
        2:
         begin
            $write("(no CRC appended)\n");
            $fwrite(outfile, "(no CRC appended)\n");
         end // case: 2
        3:
         begin
            $write("(user-defined CRC), CRC = %h\n",
                   flowrec_user_crc);
            $fwrite(outfile, "(user-defined CRC), CRC = %h\n",
                    flowrec_user_crc);
         end // case: 3
      endcase // case(flowrec_crc_option)
 
      if (flow_type >= 3) // Layer-3/4 flow
       begin
          // print L3 parameters
          case(L3_protocol_type)
            4: // IP v4
             begin
                $write("L3 protocol = 4 (IPv4)\n");
                $fwrite(outfile, "L3 protocol = 4 (IPv4)\n");
                int1 = L3_src_address;
                int2 = L3_dstn_address;
                byte_new = L3_TTL;
                $write("IP src addr = %h.%h.%h.%h, ",
                       int1[31:24], int1[23:16], int1[15:8], int1[7:0]);
                $fwrite(outfile, "IP src addr = %h.%h.%h.%h, ",
                        int1[31:24], int1[23:16], int1[15:8], int1[7:0]);
                $write("dstn addr = %h.%h.%h.%h, ",
                       int2[31:24], int2[23:16], int2[15:8], int2[7:0]);
                $fwrite(outfile, "dstn addr = %h.%h.%h.%h, ",
                        int2[31:24], int2[23:16], int2[15:8], int2[7:0]);
                $write("TTL = %0d\n", byte_new);
                $fwrite(outfile, "TTL = %0d\n", byte_new);
                byte_new = IP_service_type;
                $write("IP service type_new = %h, ", byte_new);
                $fwrite(outfile, "IP service type_new = %h, ", byte_new);
                byte_new = IP_flags;
                int1 = IP_fragment_offset;
                int2 = IP_protocol_field;
                $write("flags = %b, frag offset = %0d, protocol = %h\n",
                       byte_new[2:0], int1[12:0], int2[7:0]);
                $fwrite(outfile,
                        "flags = %b, frag offset = %0d, protocol = %h\n",
                        byte_new[2:0], int1[12:0], int2[7:0]);
                if (IP_ext_header_length != 0)
                 begin
                    // print IP extension header
                    $write("IP extension header = ");
                    $fwrite(outfile, "IP extension header = ");
                    header = IP_ext_header;
                    for (i = IP_ext_header_length -1;
                         i >= 0; i = i-1)
                     begin
                        for (j=0; j < 8; j= j+1)
                         byte_new[j] = header[i*8 +j];
                        $write("%h ", byte_new[7:0]);
                        $fwrite(outfile,"%h ", byte_new[7:0]);
                     end // for (i = IP_ext_header_length -1;...
                    $write("\n");
                    $fwrite(outfile, "\n");
                 end // if (IP_ext_header_length != 0)
             end // case: 4
          endcase // case(L3-Protocol_type)
          if (L3_custom_header_enable)
           begin
              // print L3 custom header
              $write("L3 custom header = ");
              $fwrite(outfile, "L3 custom header = ");
              header = L3_custom_header;
              for (i = L3_custom_header_length -1;
                   i >= 0; i = i-1)
               begin
                  for (j=0; j < 8; j= j+1)
                   byte_new[j] = header[i*8 +j];
                  $write("%h ", byte_new[7:0]);
                  $fwrite(outfile,"%h ", byte_new[7:0]);
               end // for (i = L3_custom_header_length;...
              $write("\n");
              $fwrite(outfile, "\n");
           end // if (L3_custom_header_enable)
 
          // print checksum option
          $write("L3 checksum option = %0d ", L3_checksum_option);
          $fwrite(outfile,
                  "L3 checksum option = %0d ", L3_checksum_option);
          case (L3_checksum_option)
            0:
             begin
                $write("(normal checksum)\n");
                $fwrite(outfile, "(normal checksum)\n");
             end // case: 0
            1:
             begin
                $write("(bad checksum)\n");
                $fwrite(outfile, "(bad checksum)\n");
             end // case: 1
            2:
             begin
                $write("(zero checksum)\n");
                $fwrite(outfile, "(zero checksum)\n");
             end // case: 2
            3:
             begin
                $write("(user-defined checksum), checksum = %h\n",
                       L3_user_checksum);
                $fwrite(outfile,
                        "(user-defined checksum), checksum = %h\n",
                        L3_user_checksum);
             end // case: 3
          endcase // case(L3_checksum_option)
       end // if (flow_type >= 3)
 
      if (flow_type >= 4) // Layer-4 flow
       begin
          // print L4 parameters
          case(L4_protocol_type)
            0:
             begin // TCP
                int1 = L4_src_port;
                int2 = L4_dstn_port;
                byte_new = TCP_flags;
                $write("TCP src port = %h, dstn port = %h, flags = %b\n",
                       int1[15:0], int2[15:0], byte_new[5:0]);
                $fwrite(outfile,
                        "TCP src port = %h, dstn port = %h, flags = %b\n",
                        int1[15:0], int2[15:0], byte_new[5:0]);
                int1 = L4_sequence_number;
                int2 = L4_ack_number;
                int3 = TCP_urgent_pointer;
                int4 = TCP_window_size;
                $write("TCP seq no = %0d, ack no = %0d, urgent ptr = %0d, window size = %0d\n",
                       int1, int2, int3[15:0], int4[15:0]);
                $fwrite(outfile,
                        "TCP seq no = %0d, ack no = %0d, urgent ptr = %0d, window size = %0d\n",
                        int1, int2, int3[15:0], int4[15:0]);
             end // case: 0
            1:
             begin // UDP
                int1 = L4_src_port;
                int2 = L4_dstn_port;
                $write("UDP src port = %h, dstn port = %h\n",
                       int1[15:0], int2[15:0]);
                $fwrite(outfile, "UDP src port = %h, dstn port = %h\n",
                        int1[15:0], int2[15:0]);
             end // case: 1
          endcase // case(L4_protocol_type)
 
          // print L4 checksum option
          $write("L4 checksum option = %0d ", L4_checksum_option);
          $fwrite(outfile,
                  "L4 checksum option = %0d ", L4_checksum_option);
          case (L4_checksum_option)
            0:
             begin
                $write("(normal checksum)\n");
                $fwrite(outfile, "(normal checksum)\n");
             end // case: 0
            1:
             begin
                $write("(bad checksum)\n");
                $fwrite(outfile, "(bad checksum)\n");
             end // case: 1
            2:
             begin
                $write("(zero checksum)\n");
                $fwrite(outfile, "(zero checksum)\n");
             end // case: 2
            3:
             begin
                $write("(user-defined checksum), checksum = %h\n",
                       L4_user_checksum);
                $fwrite(outfile,
                        "(user-defined checksum), checksum = %h\n",
                        L4_user_checksum);
             end // case: 3
          endcase // case(L4_checksum_option)
       end // if (flow_type >= 4)
 
      $write("----------------------------------\n");
      $fwrite(outfile, "----------------------------------\n");
   end
endtask
 
 
/*-------------------------------------------------------------\
 |                                                              |
 |      Tasks for transmission and reception of packets         |
 |                                                              |
 \-------------------------------------------------------------*/
 
task transmit_packet_sequence;
   // transmits a sequence of packets with header parameters already set
   // npackets = number of packets in sequence
   // IFG = inter-frame-gap
   // blocking = 0 => task returns immediately, otherwise waits
   // until all packets have been transmitted
   // timeout: used in blocking mode to avoid indefinite wait
   // value in microseconds
 
      input npackets, IFG;
   input blocking;
   input timeout_value;
   integer npackets, IFG, timeout_value;
 
 
   integer port;
   integer x, y;
   reg [47:0] mac_random;
 
   begin
      if (port_tx_busy)
       begin
          $write("%t: testbench_transmit_packet_sequence:  Port already transmitting, packets not sent\n",$time);
          if (`TERMINATE_ON_TRANSMIT_ERRORS)
           $finish;
       end // if (port_tx_busy)
      else
       begin
          packets_sent = 0;
          user_frame = 0;
          transmit_packet_count = npackets;
          if (IFG > port_min_ifg)
           current_ifg = IFG;
          else
           current_ifg = port_min_ifg;
          port_tx_busy = 1;
 
          if (blocking)
           begin
              transmit_timer_expired = 0;
              transmit_timer = timeout_value;
              transmit_timer_active = 1;
              wait((port_tx_busy == 0) ||
                   (transmit_timer_expired));
              transmit_timer_active = 0;
           end // if (blocking)
 
       end // else: !if(port_busy)
   end
endtask // port_tx_busy
 
task update_header_parameters;
   integer x, y;
   reg [47:0] mac_random;
 
   begin
      // set packet size
      case (L2_frame_size_option)
        1: // incremental
         begin
            current_pkt_size =  current_pkt_size +
                                            L2_frame_size_incr;
            if (current_pkt_size > L2_frame_size_max)
             current_pkt_size = L2_frame_size_max;
            if (current_pkt_size < L2_frame_size_min)
             current_pkt_size = L2_frame_size_min;
         end // case: 1
        2: // random
         begin
            x = $random();
            if (L2_frame_size_max != L2_frame_size_min)
             current_pkt_size = L2_frame_size_min +
                                     (x % (L2_frame_size_max - L2_frame_size_min));
            else
             current_pkt_size = L2_frame_size_min;
         end // case: 2
      endcase // case(L2_frame_size_option)
      // Set source MAC
      case (L2_src_mac_option)
        1: // incremental
         begin
            current_src_mac = current_src_mac +
                                       L2_src_mac_incr;
 
            if (current_src_mac < L2_src_mac_min)
             current_src_mac = L2_src_mac_min;
            if (current_src_mac > L2_src_mac_max)
             current_src_mac = L2_src_mac_max;
         end
        2: // random
         begin
            x = $random();
            y = $random();
            mac_random = {x[15:0], y[31:0]};
            if (L2_src_mac_min != L2_src_mac_max)
             current_src_mac = L2_src_mac_min +
                                  (mac_random % (L2_src_mac_max -
                                                 L2_src_mac_min));
            else
             current_src_mac = L2_src_mac_min;
         end // case: 2
      endcase // case(L2_src_mac_option)
 
          // Set destination MAC
      case (L2_dstn_mac_option)
        1: // incremental
         begin
            current_dstn_mac = current_dstn_mac +
                                       L2_dstn_mac_incr;
 
            if (current_dstn_mac < L2_dstn_mac_min)
             current_dstn_mac = L2_dstn_mac_min;
            if (current_dstn_mac > L2_dstn_mac_max)
             current_dstn_mac = L2_dstn_mac_max;
         end
        2: // random
         begin
            x = $random();
            y = $random();
            mac_random = {x[15:0], y[31:0]};
            if (L2_dstn_mac_min != L2_dstn_mac_max)
             current_dstn_mac = L2_dstn_mac_min +
                                   (mac_random % (L2_dstn_mac_max -
                                                  L2_dstn_mac_min));
            else
             current_dstn_mac = L2_dstn_mac_min;
         end // case: 2
      endcase // case(L2_dstn_mac_option)
 
 
      // set VLAN TCI
      case (L2_VLAN_TCI_option)
        1: // incremental
         begin
            current_VLAN_TCI = current_VLAN_TCI +
                                        L2_VLAN_TCI_incr;
 
            if (current_VLAN_TCI > L2_VLAN_TCI_max)
             current_VLAN_TCI = L2_VLAN_TCI_max;
            if (current_VLAN_TCI < L2_VLAN_TCI_min)
             current_VLAN_TCI = L2_VLAN_TCI_min;
         end // case: 1
 
        2: // random
         begin
            x = $random();
            if (L2_VLAN_TCI_max != L2_VLAN_TCI_min)
             current_VLAN_TCI = L2_VLAN_TCI_min +
                                   (x % (L2_VLAN_TCI_max -
                                         L2_VLAN_TCI_min));
            else
             current_VLAN_TCI = L2_VLAN_TCI_min;
         end // case: 2
      endcase // case(L2_VLAN_TCI_option)
 
   end
endtask // update_header_parameters
 
task transmit_packet_from_buffer;
 
   // transmits a sequence of packets from the given buffer
   // npackets = number of packets in sequence
   // IFG = inter-frame-gap
   // blocking = 0 => task returns immediately, otherwise waits
   // until all packets have been transmitted
   // timeout: used in blocking mode to avoid indefinite wait
   // value in microseconds
 
    input npackets, IFG;
   input [`MAX_PKT_SIZE*8-1:0] packet_data;
   input size;
      input blocking;
      input timeout_value;
      integer npackets, IFG, timeout_value, size;
 
   begin
      if (port_tx_busy) // port currently transmitting
       begin
          $write("%tns: testbench_transmit_packet_from_buffer:  Port already transmitting, packets not sent\n",
                 $time);
          if (`TERMINATE_ON_TRANSMIT_ERRORS)
           $finish;
       end // if (port_tx_busy)
      else
       begin
          user_frame = 1;
          transmit_packet_count = npackets;
          packets_sent = 0;
          if (IFG > port_min_ifg)
           current_ifg = IFG;
          else
           current_ifg = port_min_ifg;
          transmit_pkt = packet_data;
          transmit_pkt_size = size;
          port_tx_busy = 1;
 
          if (blocking)
           begin
              transmit_timer_expired = 0;
              transmit_timer = timeout_value;
              transmit_timer_active = 1;
              wait((port_tx_busy == 0) ||
                   (transmit_timer_expired));
              transmit_timer_active = 0;
           end // if (blocking)
       end // else: !if(port_busy)
   end
endtask // transmit_packet_from_buffer
 
task transmit_pause_frame;
   // Transmit a pause frame to the Device under Test
   // blocking = 0 => task returns immediately, otherwise waits
   // until frame has been transmitted
   // timeout: used in blocking mode to avoid indefinite wait
   // value in microseconds
 
   input [47:0] src_mac; // source MAC address
   input [15:0] pause_time;
   input blocking, timeout_value;
   integer timeout_value;
 
   reg [`MAX_PKT_SIZE*8-1:0] packet_data;
   integer size;
   begin
      if (port_tx_busy)
       begin
          $write("testbench_transmit_pause_frame:  Port already transmitting, packets not sent\n");
          if (`TERMINATE_ON_TRANSMIT_ERRORS)
           $finish;
       end // if (port_tx_busy)
      else
       begin
          user_frame = 1;
          transmit_packet_count = 1;
          packets_sent = 0;
          user_frame_current_ifg = port_min_ifg;
          construct_pause_frame(src_mac, pause_time, packet_data, size);
          transmit_pkt = packet_data;
          transmit_pkt_size = size;
          port_tx_busy = 1;
 
          if (blocking)
           begin
              transmit_timer_expired = 0;
              transmit_timer = timeout_value;
              transmit_timer_active = 1;
              wait((port_tx_busy == 0) ||
                   (transmit_timer_expired));
              transmit_timer_active = 0;
           end // if (blocking)
       end // else: !if(port_tx_busy[port])
   end
endtask // testbench_transmit_pause_frame
 
 
task read_transmit_buffer;
   // returns last packet transmitted
   // must be called when the transmitter in state
   // `TRANSMIT_FRAME to get correct CRC
   output [`MAX_PKT_SIZE*8-1:0] buffer;
   output size;
   integer size;
   begin
      buffer = transmit_pkt;
      size = transmit_pkt_size;
   end
endtask // read_transmit_buffer
 
task receive_packet;
   output [`MAX_PKT_SIZE*8-1:0] buffer;
   output size;
   integer size;
   begin
      wait (receive_data_available);
      buffer = receive_pkt;
      size = receive_pkt_size;
      receive_data_available = 0;
   end
endtask // receive_packet   
 
 
 /*-------------------------------------------------------------\
 |                                                              |
 |      Tasks for event and status reporting                    |
 |                                                              |
 \-------------------------------------------------------------*/
 
 
task get_transmit_state;
   output state;
   integer state;
   // monitors state of transmit port
   begin
      if (mii_transmit_state == 2)
       state = 1; // curently transmitting a frame
      else
       if (mii_transmit_state == 3)
        state = 2; // curently resolving a collision
       else
        if (port_tx_busy == 1)
         state = 3; // in the middle of a packet sequence
        else
         state = 0; // idle
   end
endtask // get_transmit_state
 
 
task get_receive_state;
   output state;
   integer state;
   // monitors state of receive port
   begin
      if (mii_receive_state == 2)
       state = 1; // curently receiving a frame
      else
       if (mii_receive_state == 3)
        state = 2; // curently resolving a collision
       else
        state = 0; // idle
   end
endtask // get_receive_state
 
task wait_for_event;
   // waits for designated event
   input event_type, value;
   integer event_type, value;
   begin
      case(event_type)
        1: begin // wait until transmission of current frame starts
           wait(mii_transmit_state == 2);
        end // case: 1
 
        2: begin // wait until transmission of current packet sequence ends
           wait (port_tx_busy == 0);
        end
 
        3: begin // wait until transmission of current frame ends
           @(posedge transmit_done);
        end
 
        4: begin // wait for arrival of first bit of next frame
           @(posedge mii_SFD_received);
        end
        5: begin // wait until last bit of current frame is received
           @(posedge receive_data_valid);
        end
 
        6: begin // wait until a collision is detected at the port
           wait(mii_transmit_state == 3);
        end
 
        7: begin // wait until collision detected and collision counter = value
           wait ((mii_transmit_state == 3) &&
                 (mii_collision_counter == value));
        end
        default: begin
           $display("%t ns: testbench_wait-for_event: Invalid event type_new",$time);
           if (`TERMINATE_ON_PARAM_ERRORS)
            $finish;
        end // case: default
      endcase // case(event_type)
   end
endtask // testbench_wait_for_event
 
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[/] [turbo8051/] [trunk/] [verif/] [agents/] [ethernet/] [tb_eth_tasks.v] - Blame information for rev 40

Line No.	Rev	Author	Line
1	15	dinesha
2
3			`/*-----------------------------------------------------------------`
4			`\| Ethernet MAC Testbench \|`
5			`\| \|`
6			`------------------------------------------------------------------*/`
7
8			`/*-----------------------------------------------------------------\`
9			`\| DESCRIPTION: \|`
10			`\| tb_tasks.v: Testbench tasks included in th_top.v \|`
11			`\| \|`
12			`\| Instantiated modules: none \|`
13			`\| Included files: none \|`
14			`\-----------------------------------------------------------------*/`
15
16			`/*-------------------------------------------------------------\`
17			`\| \|`
18			`\| Tasks to set port and MAC parameters such as \|`
19			`\| preamble, collision parameters, etc. \|`
20			`\| \|`
21			`\-------------------------------------------------------------*/`
22
23			`task init_port;`
24			`input [2:0] speed;`
25			`input [2:0] MII_type;`
26			`input duplex_status;`
27			`input IFG_length;`
28			`integer IFG_length;`
29
30			`begin`
31			`if ((port_mii_type != 3'b111) &&`
32			`(port_mii_type != MII_type))`
33			`begin`
34			`$write("testbench_init_port: MII type_new cannot be changed once set\n");`
35			if (`TERMINATE_ON_TASK_ERRORS)
36			`$finish;`
37			`end // if ((port_mii_type != 3'b111) &&...`
38			`else`
39			`begin`
40			`port_mii_type = MII_type;`