GNU Radio Manual and C++ API Reference 3.8.5.0
The Free & Open Software Radio Ecosystem
 
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lfsr_15_1_0.h
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1/* -*- c++ -*- */
2/*
3 * Copyright 2004 Free Software Foundation, Inc.
4 *
5 * This file is part of GNU Radio
6 *
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)
10 * any later version.
11 *
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.
16 *
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.
21 */
22
23#ifndef INCLUDED_GRI_LFSR_15_1_0_H
24#define INCLUDED_GRI_LFSR_15_1_0_H
25
26#include <gnuradio/blocks/api.h>
27
28namespace gr {
29namespace blocks {
30
31/*!
32 * \brief Linear Feedback Shift Register using primitive polynomial x^15 + x + 1
33 * \ingroup misc
34 *
35 * \details
36 * Generates a maximal length pseudo-random sequence of length
37 * 2^15 - 1 bits.
38 */
40{
41private:
42 unsigned long d_sr; // shift register
43
44public:
45 lfsr_15_1_0() { reset(); }
46
47 void reset() { d_sr = 0x7fff; }
48
50 {
51 d_sr = ((((d_sr >> 1) ^ d_sr) & 0x1) << 14) | (d_sr >> 1);
52 return d_sr & 0x1;
53 }
54
56 {
57 int v = 0;
58 for (int i = 0; i < 8; i++) {
59 v >>= 1;
60 if (next_bit())
61 v |= 0x80;
62 }
63 return v;
64 }
65};
66
67} /* namespace blocks */
68} /* namespace gr */
69
70#endif /* INCLUDED_GRI_LFSR_15_1_0_H */
Linear Feedback Shift Register using primitive polynomial x^15 + x + 1.
Definition lfsr_15_1_0.h:40
int next_byte()
Definition lfsr_15_1_0.h:55
lfsr_15_1_0()
Definition lfsr_15_1_0.h:45
int next_bit()
Definition lfsr_15_1_0.h:49
void reset()
Definition lfsr_15_1_0.h:47
#define BLOCKS_API
Definition gr-blocks/include/gnuradio/blocks/api.h:30
GNU Radio logging wrapper for log4cpp library (C++ port of log4j)
Definition basic_block.h:46
Definition cc_common.h:45