GNU Radio 3.6.2 C++ API
gri_lfsr_32k.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_32k_H
24 #define INCLUDED_GRI_LFSR_32k_H
25 
26 #include <gr_core_api.h>
27 #include <gri_lfsr_15_1_0.h>
28 
29 /*!
30  * \brief generate pseudo-random sequence of length 32768 bits.
31  * \ingroup misc
32  *
33  * This is based on gri_lfsr_15_1_0 with an extra 0 added at the end
34  * of the sequence.
35  */
36 
38  gri_lfsr_15_1_0 d_lfsr;
39  unsigned int d_count;
40 
41  public:
42  gri_lfsr_32k () { reset (); }
43 
44  void reset (){
45  d_lfsr.reset ();
46  d_count = 0;
47  }
48 
49  int next_bit (){
50  if (d_count == 32767){
51  d_count = 0;
52  return 0;
53  }
54  d_count++;
55  return d_lfsr.next_bit ();
56  }
57 
58  int next_byte (){
59  int v = 0;
60  for (int i = 0; i < 8; i++){
61  v >>= 1;
62  if (next_bit ())
63  v |= 0x80;
64  }
65  return v;
66  }
67 
68  int next_short (){
69  int v = 0;
70  for (int i = 0; i < 16; i++){
71  v >>= 1;
72  if (next_bit ())
73  v |= 0x8000;
74  }
75  return v;
76  }
77 
78 };
79 
80 #endif /* INCLUDED_GRI_LFSR_32k_H */