www.pudn.com > layer1.rar > l1gtt_baudot_functions.h
/*****************************************************************************/
/* */
/* ========================================================================= */
/* */
/* Copyright (c) 2002 */
/* Matsushita Communication Industrial, MMCD USA */
/* */
/* ========================================================================= */
/* */
/* File Name: */
/* l1gtt_baudot_functions.h */
/* */
/* Purpose: */
/* This is the header file for "l1gtt_baudot_functions.c". */
/* */
/* */
/* Warnings: */
/* */
/* */
/*****************************************************************************/
/*** Maintenance *********************************************************/
/* */
/* */
/* 02/11/2002 initial version created Laura Ning */
/* */
/*************************************************************************/
#ifndef _BAUDOT_DECODE_H_
#define BAUDOT_DECODE_H
#include "ctm_typedefs.h"
/*
*******************************************************************************
* DEFINITIONS
*******************************************************************************
*/
/* definitions (might be of global interest) */
#define BAUDOT_NUM_INFO_BITS 5 /* number of info bits per TTY character */
#define BAUDOT_SHIFT_FIGURES 27 /* code of shift to figures symbol */
#define BAUDOT_SHIFT_LETTERS 31 /* code of shift to letters symbol */
#define BAUDOT_LOGICAL_1 1
#define BAUDOT_LOGICAL_0 -1
#define BAUDOT_NON_TTY 0
#define BAUDOT_START_BIT -1
#define BAUDOT_STOP_BIT 1
#define BAUDOT_STOP_OUTPUT 2 /* STOP bit as the output of baudot_encode() to DSP */
/* definations (be only of local interest) */
#define START_OF_STOP_BIT 26
#define DETECT_WINDOW_WIDTH 4 /* A sliding window is used to detect start,stop and data bits */
#define BAUDOT_SAMPLE_DURATION 3 /* The duration to meet to determine a valid baudot bit */
/* A temporary assumption of the input buffer size, to be */
/* replaced later when TI has the actual buffer size defined */
#define MAX_WORDS_OF_BUFFER1 40 /* Number of the 5ms-bits it can contain */
#define TIME_INTERVAL_OF_BUFFER1 200 /* in the unit of ms */
#define MAX_WORDS_ONE_TTYCODE 36 /* Number of 5ms-bits a TTY character has */
#define NUM_STOP_BITS_TX 2 /* number of stop bits per character */
/* ******************************************************************/
/* Type definitions for variables that contain all states of the */
/* Baudot encoder */
/* ******************************************************************/
typedef struct
{
WORD16 cntCharsSinceLastShift;
BOOL inFigureMode;
BOOL tailBitsGenerated;
// fifo_state_t fifo_state;
} baudot_encode_state_t;
/****************************************************************************/
/* convertChar2ttyCode() */
/* ********************* */
/* Conversion from character into tty code */
/* */
/* input variables: */
/* - inChar charcater that shall be converted */
/* */
/* return value: baudot code of the input character */
/* or -1 in case that inChar is not valid (e.g. inChar=='\0')*/
/* */
/* Matthias Doerbecker, Ericsson Eurolab Deutschland (EED/N/RV), 2000/02/17 */
/****************************************************************************/
WORD16 convertChar2ttyCode(char inChar);
/****************************************************************************/
/* convertTTYcode2char() */
/* ********************* */
/* Conversion from tty code into character */
/* */
/* input variables: */
/* - ttyCode Baudot code (must be within the range 0...63) */
/* or -1 if there is nothing to convert */
/* */
/* return value: character (or '\0' if ttyCode is not valid) */
/* */
/* Matthias Doerbecker, Ericsson Eurolab Deutschland (EED/N/RV), 2000/02/17 */
/****************************************************************************/
char convertTTYcode2char(WORD16 ttyCode);
/* prototype declarations */
void init_baudot_encode(baudot_encode_state_t* state);
void baudot_encode(WORD16 inputTTYcode,
fifo_state_t* ptrOutFifoState,
baudot_encode_state_t* state);
#endif