3 * Copyright 2007 Free Software Foundation, Inc.
5 * This file is part of GNU Radio
7 * GNU Radio is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 3, or (at your option)
12 * GNU Radio is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with GNU Radio; see the file COPYING. If not, write to
19 * the Free Software Foundation, Inc., 51 Franklin Street,
20 * Boston, MA 02110-1301, USA.
23 #ifndef INCLUDED_GRI_GLFSR_H
24 #define INCLUDED_GRI_GLFSR_H
27 * \brief Galois Linear Feedback Shift Register using specified polynomial mask
30 * Generates a maximal length pseudo-random sequence of length 2^degree-1
41 gri_glfsr(int mask, int seed) { d_shift_register = seed; d_mask = mask; }
42 static int glfsr_mask(int degree);
44 unsigned char next_bit() {
45 unsigned char bit = d_shift_register & 1;
46 d_shift_register >>= 1;
48 d_shift_register ^= d_mask;
52 int mask() const { return d_mask; }
55 #endif /* INCLUDED_GRI_GLFSR_H */