`timescale 1ns/1psmodule top_tb();//Toplevel testbench for the Elevator Project.  It simulates riding up and down//in the main elevator car, setting the express elevator car security code and//riding up and down in the express elevator car  // Inputs    reg data_enable;    reg write_enable;    reg [8:0] main_external_requests;    reg exp_request_up;    reg exp_request_down;    reg main_sensor_trip;    reg [8:0] main_internal_requests;    reg [7:0] main_temp;    reg exp_update_enable;    reg [13:0] exp_input_code;    reg [7:0] exp_temp;    reg reset;    reg clk;// Outputs    wire maintenance_alarm;    wire [13:0] exp_floor_disp;    wire exp_move_up;    wire exp_move_down;    wire [13:0] main_floor_disp;    wire main_move_up;    wire main_move_down;// Bidirs    wire [7:0] maint_data;// Instantiate the UUT    top uut (        .maintenance_alarm(maintenance_alarm),         .exp_floor_disp(exp_floor_disp),         .exp_move_up(exp_move_up),         .exp_move_down(exp_move_down),         .main_floor_disp(main_floor_disp),         .main_move_up(main_move_up),         .main_move_down(main_move_down),         .data_enable(data_enable),         .write_enable(write_enable),         .maint_data(maint_data),         .main_external_requests(main_external_requests),         .exp_request_up(exp_request_up),         .exp_request_down(exp_request_down),         .main_sensor_trip(main_sensor_trip),         .main_internal_requests(main_internal_requests),         .main_temp(main_temp),         .exp_update_enable(exp_update_enable),         .exp_input_code(exp_input_code),         .exp_temp(exp_temp),         .reset(reset),         .clk(clk)        );        initial begin     //clock generation            clk=0;            forever #5 clk <= ~clk; //10ns clk        end        initial begin      // initializes all signals to zero            data_enable = 0;            write_enable = 0;            main_external_requests = 0;            exp_request_up = 0;            exp_request_down = 0;            main_sensor_trip = 0;            main_internal_requests = 0;            main_temp = 0;            exp_update_enable = 0;            exp_input_code = 0;            exp_temp = 0;            reset = 0;            #101            //wait for GSR to be released            reset = 1;      //reset the design            main_temp = 64; //set the main car temp to 64            exp_temp = 64;  //set the express car temp to 64            #40            reset = 0;            #100            main_external_requests = 9'b000001000; //request main elevator from floor 4            #50            main_external_requests = 9'b000000000;            main_internal_requests = 9'b001000000; //requests main elevator to go to floor 7            #40            main_internal_requests = 9'b000000000;            main_external_requests = 9'b000000001; //requests main elevator from floor 1            #70            main_external_requests = 9'b000000000;            main_internal_requests = 9'b100000000; //requests main elevator to go to floor 9            #100            main_internal_requests = 9'b000000000;            #100            exp_input_code = 14'b10101010101010;   //set the express car code             #10            exp_update_enable = 1;            #20            exp_update_enable = 0;            #10            exp_input_code = 14'b00000000000000;            #200            exp_request_up = 1;                    //request to go up in express car            #10            exp_input_code = 14'b10101010101010;   //enter express security code to go up             #10            exp_request_up = 0;             #10            exp_input_code = 14'b00000000000000;            #40            exp_request_down = 1;                  //request to go down in the express car               #10            exp_request_down = 0;             #1000            main_external_requests = 9'b000000000;        endendmodule