题解 | #含有无关项的序列检测#

`timescale 1ns/1ns
module sequence_detect(
	input clk,
	input rst_n,
	input a,
	output reg match
	);
	reg [8:0]str;

	always @(posedge clk or negedge rst_n) begin
		if(!rst_n)
			str <= 'b0;
		else 
			str <= {str[8:0],a};
	end
	
	always @(posedge clk or negedge rst_n) begin
		if(!rst_n)
			match <= 0;
		else 
			match <= (str~^9'b011xxx110) === 9'b111xxx111 ? 1 : 0;//~^同或起到按位比较是否等于并返回的作用
	end 



endmodule