00001 /* 00002 * SpanDSP - a series of DSP components for telephony 00003 * 00004 * async.h - Asynchronous serial bit stream encoding and decoding 00005 * 00006 * Written by Steve Underwood <steveu@coppice.org> 00007 * 00008 * Copyright (C) 2003 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 version 2, as 00014 * published by the Free Software Foundation. 00015 * 00016 * This program is distributed in the hope that it will be useful, 00017 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00018 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00019 * GNU General Public License for more details. 00020 * 00021 * You should have received a copy of the GNU General Public License 00022 * along with this program; if not, write to the Free Software 00023 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 00024 * 00025 * $Id: async.h,v 1.9 2007/04/08 08:16:17 steveu Exp $ 00026 */ 00027 00028 /*! \file */ 00029 00030 /*! \page async_page Asynchronous bit stream processing 00031 \section async_page_sec_1 What does it do? 00032 The asynchronous serial bit stream processing module provides 00033 generation and decoding facilities for most asynchronous data 00034 formats. It supports: 00035 - 1 or 2 stop bits. 00036 - Odd, even or no parity. 00037 - 5, 6, 7, or 8 bit characters. 00038 - V.14 rate adaption. 00039 The input to this module is a bit stream. This means any symbol synchronisation 00040 and decoding must occur before data is fed to this module. 00041 00042 \section async_page_sec_2 The transmitter 00043 ???. 00044 00045 \section async_page_sec_3 The receiver 00046 ???. 00047 */ 00048 00049 #if !defined(_SPANDSP_ASYNC_H_) 00050 #define _SPANDSP_ASYNC_H_ 00051 00052 /* Special "bit" values for the put and get bit functions */ 00053 enum 00054 { 00055 /*! \brief The carrier signal has dropped. */ 00056 PUTBIT_CARRIER_DOWN = -1, 00057 /*! \brief The carrier signal is up. This merely indicates that carrier 00058 energy has been seen. It is not an indication that the carrier is either 00059 valid, or of the expected type. */ 00060 PUTBIT_CARRIER_UP = -2, 00061 /*! \brief The modem is training. This is an early indication that the 00062 signal seems to be of the right type. This may be needed in time critical 00063 applications, like T.38, to forward an early indication of what is happening 00064 on the wire. */ 00065 PUTBIT_TRAINING_IN_PROGRESS = -3, 00066 /*! \brief The modem has trained, and is ready for data exchange. */ 00067 PUTBIT_TRAINING_SUCCEEDED = -4, 00068 /*! \brief The modem has failed to train. */ 00069 PUTBIT_TRAINING_FAILED = -5, 00070 /*! \brief Packet framing (e.g. HDLC framing) is OK. */ 00071 PUTBIT_FRAMING_OK = -6, 00072 /*! \brief The data stream has ended. */ 00073 PUTBIT_END_OF_DATA = -7, 00074 /*! \brief An abort signal (e.g. an HDLC abort) has been received. */ 00075 PUTBIT_ABORT = -8, 00076 /*! \brief A break signal (e.g. an async break) has been received. */ 00077 PUTBIT_BREAK = -9 00078 }; 00079 00080 /*! Message put function for data pumps */ 00081 typedef void (*put_msg_func_t)(void *user_data, const uint8_t *msg, int len); 00082 00083 /*! Message get function for data pumps */ 00084 typedef int (*get_msg_func_t)(void *user_data, uint8_t *msg, int max_len); 00085 00086 /*! Byte put function for data pumps */ 00087 typedef void (*put_byte_func_t)(void *user_data, int byte); 00088 00089 /*! Byte get function for data pumps */ 00090 typedef int (*get_byte_func_t)(void *user_data); 00091 00092 /*! Bit put function for data pumps */ 00093 typedef void (*put_bit_func_t)(void *user_data, int bit); 00094 00095 /*! Bit get function for data pumps */ 00096 typedef int (*get_bit_func_t)(void *user_data); 00097 00098 /*! No parity bit should be used */ 00099 #define ASYNC_PARITY_NONE 0 00100 /*! An even parity bit will exist, after the data bits */ 00101 #define ASYNC_PARITY_EVEN 1 00102 /*! An odd parity bit will exist, after the data bits */ 00103 #define ASYNC_PARITY_ODD 2 00104 00105 /*! 00106 Asynchronous data transmit descriptor. This defines the state of a single 00107 working instance of a byte to asynchronous serial converter, for use 00108 in FSK modems. 00109 */ 00110 typedef struct 00111 { 00112 /*! \brief The number of data bits per character. */ 00113 int data_bits; 00114 /*! \brief The type of parity. */ 00115 int parity; 00116 /*! \brief The number of stop bits per character. */ 00117 int stop_bits; 00118 /*! \brief A pointer to the callback routine used to get characters to be transmitted. */ 00119 get_byte_func_t get_byte; 00120 /*! \brief An opaque pointer passed when calling get_byte. */ 00121 void *user_data; 00122 00123 /*! \brief A current, partially transmitted, character. */ 00124 int byte_in_progress; 00125 /*! \brief The current bit position within a partially transmitted character. */ 00126 int bitpos; 00127 int parity_bit; 00128 } async_tx_state_t; 00129 00130 /*! 00131 Asynchronous data receive descriptor. This defines the state of a single 00132 working instance of an asynchronous serial to byte converter, for use 00133 in FSK modems. 00134 */ 00135 typedef struct 00136 { 00137 /*! \brief The number of data bits per character. */ 00138 int data_bits; 00139 /*! \brief The type of parity. */ 00140 int parity; 00141 /*! \brief The number of stop bits per character. */ 00142 int stop_bits; 00143 /*! \brief TRUE if V.14 rate adaption processing should be performed. */ 00144 int use_v14; 00145 /*! \brief A pointer to the callback routine used to handle received characters. */ 00146 put_byte_func_t put_byte; 00147 /*! \brief An opaque pointer passed when calling put_byte. */ 00148 void *user_data; 00149 00150 /*! \brief A current, partially complete, character. */ 00151 int byte_in_progress; 00152 /*! \brief The current bit position within a partially complete character. */ 00153 int bitpos; 00154 int parity_bit; 00155 00156 int parity_errors; 00157 int framing_errors; 00158 } async_rx_state_t; 00159 00160 #if defined(__cplusplus) 00161 extern "C" 00162 { 00163 #endif 00164 00165 /*! Initialise an asynchronous data transmit context. 00166 \brief Initialise an asynchronous data transmit context. 00167 \param s The transmitter context. 00168 \param data_bits The number of data bit. 00169 \param parity_bits The type of parity. 00170 \param stop_bits The number of stop bits. 00171 \param use_v14 TRUE if V.14 rate adaption processing should be used. 00172 \param get_byte The callback routine used to get the data to be transmitted. 00173 \param user_data An opaque pointer. */ 00174 void async_tx_init(async_tx_state_t *s, 00175 int data_bits, 00176 int parity_bits, 00177 int stop_bits, 00178 int use_v14, 00179 get_byte_func_t get_byte, 00180 void *user_data); 00181 00182 /*! Get the next bit of a transmitted serial bit stream. 00183 \brief Get the next bit of a transmitted serial bit stream. 00184 \param user_data An opaque point which must point to a transmitter context. 00185 \return the next bit, or PUTBIT_END_OF_DATA to indicate the data stream has ended. */ 00186 int async_tx_get_bit(void *user_data); 00187 00188 /*! Initialise an asynchronous data receiver context. 00189 \brief Initialise an asynchronous data receiver context. 00190 \param s The receiver context. 00191 \param data_bits The number of data bits. 00192 \param parity_bits The type of parity. 00193 \param stop_bits The number of stop bits. 00194 \param use_v14 TRUE if V.14 rate adaption processing should be used. 00195 \param put_byte The callback routine used to put the received data. 00196 \param user_data An opaque pointer. */ 00197 void async_rx_init(async_rx_state_t *s, 00198 int data_bits, 00199 int parity_bits, 00200 int stop_bits, 00201 int use_v14, 00202 put_byte_func_t put_byte, 00203 void *user_data); 00204 00205 /*! Accept a bit from a received serial bit stream 00206 \brief Accept a bit from a received serial bit stream 00207 \param user_data An opaque point which must point to a receiver context. 00208 \param bit The new bit. Some special values are supported for this field. 00209 - PUTBIT_CARRIER_UP 00210 - PUTBIT_CARRIER_DOWN 00211 - PUTBIT_TRAINING_SUCCEEDED 00212 - PUTBIT_TRAINING_FAILED 00213 - PUTBIT_END_OF_DATA */ 00214 void async_rx_put_bit(void *user_data, int bit); 00215 00216 #if defined(__cplusplus) 00217 } 00218 #endif 00219 00220 #endif 00221 /*- End of file ------------------------------------------------------------*/