3 * Copyright 2004 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 2, 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.
22 #ifndef INCLUDED_GR_CHECK_LFSR_32K_S_H
23 #define INCLUDED_GR_CHECK_LFSR_32K_S_H
25 #include <gr_sync_block.h>
26 #include <gri_lfsr_32k.h>
29 class gr_check_lfsr_32k_s;
30 typedef boost::shared_ptr<gr_check_lfsr_32k_s> gr_check_lfsr_32k_s_sptr;
32 gr_check_lfsr_32k_s_sptr gr_make_check_lfsr_32k_s ();
35 * \brief sink that checks if its input stream consists of a lfsr_32k sequence.
38 * This sink is typically used along with gr_lfsr_32k_source_s to test
39 * the USRP using its digital loopback mode.
41 class gr_check_lfsr_32k_s : public gr_sync_block
43 friend gr_check_lfsr_32k_s_sptr gr_make_check_lfsr_32k_s ();
46 SEARCHING, // searching for synchronization
54 unsigned int d_history; // bitmask of decisions
56 long d_ntotal; // total number of shorts
57 long d_nright; // # of correct shorts
58 long d_runlength; // # of correct shorts in a row
60 static const int BUFSIZE = 2048 - 1; // ensure pattern isn't packet aligned
62 unsigned short d_buffer[BUFSIZE];
65 gr_check_lfsr_32k_s ();
67 void enter_SEARCHING ();
74 d_history = (d_history << 1) | 0x1;
80 d_history = (d_history << 1) | 0x0;
84 bool right_three_times () { return (d_history & 0x7) == 0x7; }
85 bool wrong_three_times () { return (d_history & 0x7) == 0x0; }
87 void log_error (unsigned short expected, unsigned short actual);
91 int work (int noutput_items,
92 gr_vector_const_void_star &input_items,
93 gr_vector_void_star &output_items);
95 long ntotal () const { return d_ntotal; }
96 long nright () const { return d_nright; }
97 long runlength () const { return d_runlength; }
102 #endif /* INCLUDED_GR_CHECK_LFSR_32K_S_H */