mp3_drv.c

ATMEL公司AT89C51SND1为主控制器MP3源代码

/*C**************************************************************************
* NAME:         mp3_drv.c
*----------------------------------------------------------------------------
* Copyright (c) 2003 Atmel.
*----------------------------------------------------------------------------
* RELEASE:      snd1c-refd-nf-4_0_3      
* REVISION:     1.7     
*----------------------------------------------------------------------------
* PURPOSE:
* This file contains the MP3 driver routines
*
* NOTES:
* Driver Configuration:
*   - MP3_CRC_SKIP in config.h define as:
*      TRUE:  to skip frames with CRC errors 
*      FALSE: to play frame with CRC errors
* Global Variables:
*   - None
*****************************************************************************/

/*_____ I N C L U D E S ____________________________________________________*/

#include "config.h"                         /* system configuration */
#include "mp3_drv.h"                        /* mp3 driver definition */


/*_____ M A C R O S ________________________________________________________*/


/*_____ D E F I N I T I O N ________________________________________________*/


/*_____ D E C L A R A T I O N ______________________________________________*/


/*F**************************************************************************
* NAME: mp3_init
*----------------------------------------------------------------------------
* PARAMS:
*
* return:
*----------------------------------------------------------------------------
* PURPOSE:
*   MP3 decoder initialisation
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*----------------------------------------------------------------------------
* REQUIREMENTS: 
* ram/xram:
* cycle:
* stack: 
* code:
*****************************************************************************/
void mp3_init (void)
{
#if MP3_CRC_SKIP == TRUE
  Mp3_skip_crc_error();                 /* skip frames with crc error */
#else
  Mp3_play_crc_error();                 /* play frames with crc error */
#endif
  Mp3_enable();                         /* MP3 enable */
}


/*F**************************************************************************
* NAME: mp3_set_prio
*----------------------------------------------------------------------------
* PARAMS:
*
* return:
*----------------------------------------------------------------------------
* PURPOSE:
*   Set the MP3 decoder priority interrupt
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*----------------------------------------------------------------------------
* REQUIREMENTS: 
* ram/xram:
* cycle:
* stack: 
* code:
*****************************************************************************/
void mp3_set_prio (Byte priority)
{
  if ((priority == 1) || (priority == 3))     /* set LSB priority bit */
  {
    IPL0 |= MSK_EMP3;
  }
  if ((priority == 2) || (priority == 3))     /* set MSB priority bit */
  {
    IPH0 |= MSK_EMP3;
  }
}


/*F**************************************************************************
* NAME: mp3_stop
*----------------------------------------------------------------------------
* PARAMS:
*
* return:
*----------------------------------------------------------------------------
* PURPOSE:
*   Close the MP3 decoder
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*----------------------------------------------------------------------------
* REQUIREMENTS: 
* ram/xram:
* cycle:
* stack: 
* code:
*****************************************************************************/
void mp3_stop (void)
{
  Mp3_disable_int();                          /* disable MP3 IT */
  Mp3_disable();                              /* disable decoding */
  Mp3_ack_int();                              /* clear pending interrupt */
}


/*F**************************************************************************
* NAME: mp3_restart
*----------------------------------------------------------------------------
* PARAMS:
*
* return:
*----------------------------------------------------------------------------
* PURPOSE:
*   MP3 decoder restart
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*----------------------------------------------------------------------------
* REQUIREMENTS: 
* ram/xram:
* cycle:
* stack: 
* code:
*****************************************************************************/
void mp3_restart (void)
{
  Mp3_disable();
  Mp3_enable();
}