Subversion Repositories jt51

/*  This file is part of JT51.
 
    JT51 is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
 
    JT51 is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    along with JT51.  If not, see <http://www.gnu.org/licenses/>.
 
	Author: Jose Tejada Gomez. Twitter: @topapate
	Version: 1.0
	Date: 27-10-2016
	*/
 
`timescale 1ns / 1ps
 
/*
 
	tab size 4
 
*/
 
module jt51_lfo_lfsr #(parameter init=220 )(
	input	rst,
	input	clk,
	input	base,
	output	out
);
 
reg [18:0] bb;
assign out = bb[18];
 
reg last_base;
 
always @(posedge clk) begin : base_counter
	if( rst ) begin
		bb			<= init[18:0];
		last_base 	<= 1'b0;
	end
	else begin
		last_base <= base;
		if( last_base != base ) begin	
			bb[18:1] 	<= bb[17:0];
			bb[0]		<= ^{bb[0],bb[1],bb[14],bb[15],bb[17],bb[18]};
		end
	end
end
 
endmodule