`timescale 1ns/1ns module gray_counter( input clk, input rst_n, output wire [3:0] gray_out ); //使用Moore状态机实现 parameter s0 =8'b0000_0000, s1 = 8'b0001_0001, s2 = 8'b0011_0011, s3 = 8'b0010_0010, s4 = 8'b0110_0110, s5 = 8'b0111_0111, s6 = 8'b0101_0101, s7 = 8'b0100_0100, s8 = 8'b1100_1100, s9 = 8'b110...