diff options
Diffstat (limited to 'gr-blocks/lib/check_lfsr_32k_s_impl.cc')
| -rw-r--r-- | gr-blocks/lib/check_lfsr_32k_s_impl.cc | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/gr-blocks/lib/check_lfsr_32k_s_impl.cc b/gr-blocks/lib/check_lfsr_32k_s_impl.cc new file mode 100644 index 0000000000..5664067591 --- /dev/null +++ b/gr-blocks/lib/check_lfsr_32k_s_impl.cc @@ -0,0 +1,179 @@ +/* -*- c++ -*- */ +/* + * Copyright 2004,2010,2013 Free Software Foundation, Inc. + * + * This file is part of GNU Radio + * + * GNU Radio 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, or (at your option) + * any later version. + * + * GNU Radio 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 GNU Radio; see the file COPYING. If not, write to + * the Free Software Foundation, Inc., 51 Franklin Street, + * Boston, MA 02110-1301, USA. + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include "check_lfsr_32k_s_impl.h" +#include <gr_io_signature.h> +#include <stdlib.h> +#include <stdio.h> + +namespace gr { + namespace blocks { + + check_lfsr_32k_s::sptr + check_lfsr_32k_s::make() + { + return gnuradio::get_initial_sptr + (new check_lfsr_32k_s_impl()); + } + + check_lfsr_32k_s_impl::check_lfsr_32k_s_impl() + : gr_sync_block("check_lfsr_32k", + gr_make_io_signature(1, 1, sizeof(short)), + gr_make_io_signature(0, 0, 0)), + d_state(SEARCHING), d_history(0), d_ntotal(0), d_nright(0), + d_runlength(0), d_index(0) + { + lfsr_32k lfsr; + + for(int i = 0; i < BUFSIZE; i++) + d_buffer[i] = lfsr.next_short(); + + enter_SEARCHING(); + } + + check_lfsr_32k_s_impl::~check_lfsr_32k_s_impl() + { + } + + int + check_lfsr_32k_s_impl::work(int noutput_items, + gr_vector_const_void_star &input_items, + gr_vector_void_star &output_items) + { + unsigned short *in = (unsigned short*)input_items[0]; + + for(int i = 0; i < noutput_items; i++) { + unsigned short x = in[i]; + unsigned short expected; + + switch(d_state) { + case MATCH0: + if(x == d_buffer[0]) + enter_MATCH1(); + break; + + case MATCH1: + if(x == d_buffer[1]) + enter_MATCH2(); + else + enter_MATCH0(); + break; + + case MATCH2: + if(x == d_buffer[2]) + enter_LOCKED(); + else + enter_MATCH0(); + break; + + case LOCKED: + expected = d_buffer[d_index]; + d_index = d_index + 1; + if(d_index >= BUFSIZE) + d_index = 0; + + if(x == expected) + right(); + else { + wrong(); + log_error(expected, x); + if(wrong_three_times()) + enter_SEARCHING(); + } + break; + + default: + abort(); + } + + d_ntotal++; + } + + return noutput_items; + } + + void + check_lfsr_32k_s_impl::enter_SEARCHING() + { + d_state = SEARCHING; + wrong(); // reset history + wrong(); + wrong(); + + d_runlength = 0; + d_index = 0; // reset LFSR to beginning + + if(0) + fprintf(stdout, "check_lfsr_32k: enter_SEARCHING at offset %8ld (0x%08lx)\n", + d_ntotal, d_ntotal); + + enter_MATCH0(); + } + + void + check_lfsr_32k_s_impl::enter_MATCH0() + { + d_state = MATCH0; + } + + void + check_lfsr_32k_s_impl::enter_MATCH1() + { + d_state = MATCH1; + } + + void + check_lfsr_32k_s_impl::enter_MATCH2() + { + d_state = MATCH2; + } + + void + check_lfsr_32k_s_impl::enter_LOCKED() + { + d_state = LOCKED; + right(); // setup history + right(); + right(); + + d_index = 3; // already matched first 3 items + + if(0) + fprintf(stdout, "check_lfsr_32k: enter_LOCKED at offset %8ld (0x%08lx)\n", + d_ntotal, d_ntotal); + } + + void + check_lfsr_32k_s_impl::log_error(unsigned short expected, unsigned short actual) + { + if(0) + fprintf(stdout, + "check_lfsr_32k: expected %5d (0x%04x) got %5d (0x%04x) offset %8ld (0x%08lx)\n", + expected, expected, actual, actual, d_ntotal, d_ntotal); + } + + } /* namespace blocks */ +} /* namespace gr */ |