VL26 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] seq;
always@(posedge clk or negedge rst_n)begin
if(!rst_n)
seq <= 0;
else
seq <= {seq[7:0], a};
end
always@(posedge clk or negedge rst_n)begin
if(!rst_n)
match <= 0;
else
casez(seq)
9'b011_???_110: match <= 1;
default: match <= 0;
endcase
end
endmodule