怎么让下面这段代码在八位二进制数中检测到11010

reg [7:0]din_r;

assign led=din;

reg [2:0] state;/eck serial 5'b0_0000
always @ (posedge clk or negedge rst_n)
if (！rst_n) begin
    flag<=1'b0;
    din_r<=din;
    state<='d0;
end
else if(!en) begin
    case (state):
        'd0:
            begin
                flag <= 1'b0;
                din_r <={din_r[6:0],1'b1};
                if (din_r[7]==1'b0)
                    state <= 'd1;
                else
                    state <= 'd0;
            end
        'd1 :
            begin
                flag <= 1'b0;
                din_r <={din_r[6:0],1'b1};
                if (din_r[7]==1'b0)
                    state <= 'd2;
                else
                    state <= 'd0;
            end
        'd2 :
            begin
                flag <= 1'b0;
                din_r <={din_r[6:0],1'b1};
                if (din_r[7]==1'b0)
                    state <= 'd3;
                else
                    state <= 'd0;
            end
        'd3 :
            begin
                flag <= 1'b0;
                din_r <={din_r[6:0],1'b1};
                if (din_r[7]==1'b0)
                    state <= 'd4;
                else
                    state <= 'd0;
            end
        'd4 :
            begin
                if (din_r[7]==1'b0)
                    flage <= 1'b1;
                end
            default :
                begin
                    state <= 'd0;
                    flag <= 1'b0;
                end
        endcase
    end
                

endmodule