io_dce.c

话带数据中传真解调程序

/*
 *
 *	Stuff that handles dce IO stuff.
 *
 *	Copyright (c) 1999 Richard J.M. Close
 *
 *	Can be freely distributed and used under the terms of the GNU GPL.
 */

#include "io_dce.h"


unsigned char io_dce_tx_fifo_empty(void)
{
  unsigned char var1 = 0;

  if(io_dce_tx_wptr == io_dce_tx_rptr)
    x_send_mail (0x82, 1, &var1, 1);
  // Jamie's diss has 83 not 82!
  return var1;
}

void io_init_dce_tx_fifo(void)
{
 
  io_dce_tx_eptr = io_dce_tx_sptr;
  io_dce_tx_sptr = &io_dce_tx_buff[0];
  io_dce_tx_wptr = io_dce_tx_sptr;
  io_dce_tx_rptr = io_dce_tx_sptr;
}

void io_init_dce_rx_fifo(void)
{
  io_dce_rx_eptr = io_dce_tx_eptr;
  io_dce_rx_sptr = &io_dce_rx_buff[0];
  io_dce_rx_wptr = io_dce_rx_sptr;
  io_dce_rx_rptr = io_dce_rx_sptr;
}

unsigned int io_get_dce_rx_count(void)
{
  unsigned int eax, ecx;

  ecx = (unsigned int)(io_dce_rx_eptr - io_dce_rx_sptr);
  ecx = ecx/2;

  if (io_dce_rx_wptr < io_dce_rx_rptr) goto loc_3AD4C;

  eax = io_dce_rx_wptr - io_dce_rx_rptr;
  eax = eax/2;
  return eax;

loc_3AD4C:
  eax = io_dce_rx_wptr - io_dce_rx_rptr;
  eax = eax/2;
  eax = eax + ecx;
  return eax;
}

// Transmits a defined number of words.
void io_write_dce_fifo (unsigned int count, unsigned short wData)
{
  unsigned int tempCount = count;

  if (count != 0){
    {
      // Copy data (word) to fifo.
      *io_dce_tx_wptr = (unsigned char) (wData & 0xff);  //LSB
      io_dce_tx_wptr++;
      *io_dce_tx_wptr = (unsigned char) (wData / 256);   //MSB
      io_dce_tx_wptr++;
      
      // Make sure we are not at end of buffer.
      if (io_dce_tx_wptr >= io_dce_tx_eptr)
	// Reached end of tx buffer so reset pointer to start.
	io_dce_tx_wptr = io_dce_tx_sptr;
      
      tempCount--;
    } while (tempCount > 0);
  }
  // Try to transmit the data.
  io_start_dce_transmit();
}

void io_start_dce_transmit(void)
{
  printf("io_start_dce_transmit: not yet implemented!");
}