//p(z) = z^6 + z + 1

`timescale 1ns/1ns
module pn6
    (
    input               rst,
    input               clk,

    output              pn_out
    );

wire            pn_tmp;
reg     [5:0]   pn_shift;

always @ (posedge clk or posedge rst)
begin
    if (rst == 1'b1)
        pn_shift <= 6'h3f;
    else
        pn_shift <= {pn_tmp,pn_shift[5:1]};
end

assign pn_tmp = pn_shift[1] ^ pn_shift[0];
assign pn_out = pn_shift[0];

endmodule

`timescale 1ns/1ns
module tb;
reg         clk;
reg         rst;

initial clk = 0;

always #5 clk = ~clk;

initial
begin
    rst = 1'b1;
    #200 rst = 1'b0;
end

pn6 u_pn6
    (
    .rst(rst),
    .clk(clk),

    .pn_out()
    );

integer file_wr;
initial
begin
    file_wr = $fopen("./pn_out.txt","w");
end

always @ (posedge clk)
begin
    if (rst == 1'b0)
        $fwrite(file_wr,"%d\n",u_pn6.pn_out);
    else ;
end

endmodule

%p(z) = z^6 + z + 1
h = seqgen.pn('GenPoly', [6 1 0],...
              'InitialStates',[1 1 1 1 1 1],...
              'CurrentStates',[1 1 1 1 1 1],...
              'NumBitsOut',180);
generate(h)