`timescale 1ns / 1ps module tb3( ); reg in = 0; reg [1:0] st = 0; wire [1:0] nst; wire out; initial begin in = 0; st = 1; #10; in = 1; st = 3; #10; st = 1; #10; st = 2; #10; st = 1; #10; in = 0; #10; in = 1; st = 0; #10; st = 2; end top_module top_inst( .in(in), .state(st), .next_state(nst), .out(out) ); endmodule