00001 /* 00002 * SpanDSP - a series of DSP components for telephony 00003 * 00004 * bert.h - Bit error rate tests. 00005 * 00006 * Written by Steve Underwood <steveu@coppice.org> 00007 * 00008 * Copyright (C) 2004 Steve Underwood 00009 * 00010 * All rights reserved. 00011 * 00012 * This program is free software; you can redistribute it and/or modify 00013 * it under the terms of the GNU General Public License as published by 00014 * the Free Software Foundation; either version 2 of the License, or 00015 * (at your option) any later version. 00016 * 00017 * This program is distributed in the hope that it will be useful, 00018 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00019 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00020 * GNU General Public License for more details. 00021 * 00022 * You should have received a copy of the GNU General Public License 00023 * along with this program; if not, write to the Free Software 00024 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 00025 * 00026 * $Id: bert.h,v 1.9 2005/12/29 09:54:24 steveu Exp $ 00027 */ 00028 00029 #if !defined(_BERT_H_) 00030 #define _BERT_H_ 00031 00032 /*! \page bert_page The Bit Error Rate tester 00033 \section bert_page_sec_1 What does it do? 00034 The Bit Error Rate tester generates a pseudo random bit stream. It also accepts such 00035 a pattern, synchronises to it, and checks the bit error rate in this stream. 00036 00037 \section bert_page_sec_2 How does it work? 00038 The Bit Error Rate tester generates a bit stream, with a repeating 2047 bit pseudo 00039 random pattern, using an 11 stage polynomial generator. It also accepts such a pattern, 00040 synchronises to it, and checks the bit error rate in this stream. If the error rate is 00041 excessive the tester assumes synchronisation has been lost, and it attempts to 00042 resynchronise with the stream. 00043 00044 The bit error rate is continuously assessed against decadic ranges - 00045 > 1 in 10^2 00046 > 1 in 10^3 00047 > 1 in 10^4 00048 > 1 in 10^5 00049 > 1 in 10^6 00050 > 1 in 10^7 00051 < 1 in 10^7 00052 To ensure fairly smooth results from this assessment, each decadic level is assessed 00053 over 10/error rate bits. That is, to assess if the signal's BER is above or below 1 in 10^5 00054 the software looks over 10*10^5 => 10^6 bits. 00055 */ 00056 00057 enum 00058 { 00059 BERT_REPORT_SYNCED, 00060 BERT_REPORT_UNSYNCED, 00061 BERT_REPORT_REGULAR, 00062 BERT_REPORT_GT_10_2, 00063 BERT_REPORT_LT_10_2, 00064 BERT_REPORT_LT_10_3, 00065 BERT_REPORT_LT_10_4, 00066 BERT_REPORT_LT_10_5, 00067 BERT_REPORT_LT_10_6, 00068 BERT_REPORT_LT_10_7 00069 }; 00070 00071 /* The QBF strings should be: 00072 "VoyeZ Le BricK GeanT QuE J'ExaminE PreS Du WharF 123 456 7890 + - * : = $ % ( )" 00073 "ThE QuicK BrowN FoX JumpS OveR ThE LazY DoG 123 456 7890 + - * : = $ % ( )" 00074 */ 00075 00076 enum 00077 { 00078 BERT_PATTERN_ZEROS, 00079 BERT_PATTERN_ONES, 00080 BERT_PATTERN_7_TO_1, 00081 BERT_PATTERN_3_TO_1, 00082 BERT_PATTERN_1_TO_1, 00083 BERT_PATTERN_1_TO_3, 00084 BERT_PATTERN_1_TO_7, 00085 BERT_PATTERN_QBF, 00086 BERT_PATTERN_ITU_O151_23, 00087 BERT_PATTERN_ITU_O151_20, 00088 BERT_PATTERN_ITU_O151_15, 00089 BERT_PATTERN_ITU_O152_11, 00090 BERT_PATTERN_ITU_O153_9 00091 }; 00092 00093 typedef void (*bert_report_func_t)(void *user_data, int reason); 00094 00095 /*! 00096 Bit error rate tester (BERT) descriptor. This defines the working state for a 00097 single instance of the BERT. 00098 */ 00099 typedef struct 00100 { 00101 int pattern; 00102 int pattern_class; 00103 bert_report_func_t reporter; 00104 void *user_data; 00105 int report_frequency; 00106 int limit; 00107 00108 uint32_t tx_reg; 00109 int tx_step; 00110 int tx_step_bit; 00111 int tx_bits; 00112 int tx_zeros; 00113 00114 uint32_t rx_reg; 00115 uint32_t ref_reg; 00116 uint32_t master_reg; 00117 int rx_step; 00118 int rx_step_bit; 00119 int resync; 00120 int rx_bits; 00121 int rx_zeros; 00122 int resync_len; 00123 int resync_percent; 00124 int resync_bad_bits; 00125 int resync_cnt; 00126 int total_bits; 00127 int bad_bits; 00128 int resyncs; 00129 00130 uint32_t mask; 00131 int shift; 00132 int shift2; 00133 int max_zeros; 00134 int invert; 00135 int resync_time; 00136 00137 int decade_ptr[8]; 00138 int decade_bad[8][10]; 00139 int step; 00140 int error_rate; 00141 00142 int bit_error_status; 00143 int report_countdown; 00144 } bert_state_t; 00145 00146 /*! 00147 Bit error rate tester (BERT) results descriptor. This is used to report the 00148 results of a BER test. 00149 */ 00150 typedef struct 00151 { 00152 int total_bits; 00153 int bad_bits; 00154 int resyncs; 00155 } bert_results_t; 00156 00157 #ifdef __cplusplus 00158 extern "C" { 00159 #endif 00160 00161 /*! Initialise a BERT context. 00162 \param s The BERT context. 00163 \param limit The maximum test duration. 00164 \param pattern One of the supported BERT signal patterns. 00165 \param resync_len ??? 00166 \param resync_percent The percentage of bad bits which will cause a resync. 00167 \return The BERT context. */ 00168 bert_state_t *bert_init(bert_state_t *s, int limit, int pattern, int resync_len, int resync_percent); 00169 00170 /*! Get the next bit of the BERT sequence from the generator. 00171 \param s The BERT context. 00172 \return The bit. */ 00173 int bert_get_bit(bert_state_t *s); 00174 00175 /*! Put the next bit of the BERT sequence to the analyser. 00176 \param s The BERT context. 00177 \param bit The bit. */ 00178 void bert_put_bit(bert_state_t *s, int bit); 00179 00180 /*! Set the callback function for reporting the test status. 00181 \param s The BERT context. 00182 \param freq The required frequency of regular reports. 00183 \param reporter The callback function. 00184 \param user_data An opaque pointer passed to the reporter routine. */ 00185 void bert_set_report(bert_state_t *s, int freq, bert_report_func_t reporter, void *user_data); 00186 00187 /*! Get the results of the BERT. 00188 \param s The BERT context. 00189 \param results The results. 00190 \return The size of the result structure. */ 00191 int bert_result(bert_state_t *s, bert_results_t *results); 00192 00193 #ifdef __cplusplus 00194 } 00195 #endif 00196 00197 #endif 00198 /*- End of file ------------------------------------------------------------*/