`timescale 1ns/1ns module sequence_detect( input clk, input rst_n, input a, output reg match ); reg[7:0]buff; always@(posedge clk or negedge rst_n) begin if(!rst_n) buff<=8'b0; else buff<={buff[6:0],a}; end always@(posedge clk or negedge rst_n) begin if(!rst_n) match<=0; else if(buff===8'b01110001) match<=1; else match<=0; end endmodule