MP3播放器详细设计方案

				/*H**************************************************************************
				* NAME:         i2c_lib.h
				*----------------------------------------------------------------------------
				* Copyright (c) 2002 Atmel.
				*----------------------------------------------------------------------------
				* RELEASE:      snd1c-refd-nf-3_0_0
				* REVISION:     1.2
				*----------------------------------------------------------------------------
				* PURPOSE:
				* This file contains the I2C driver definition
				*****************************************************************************/
				
				#ifndef _I2C_LIB_H_
				#define _I2C_LIB_H_
				
				#define I2C_NB_SLAVE_DATA   100
				
				
				/*_____ D E F I N I T I O N S ______________________________________________*/
				
				typedef struct{ unsigned char address;
				                unsigned char rw;
				                unsigned char nbbytes;
				                unsigned char *buf;
				              } I2C_type_message;
				
				
				/*_____ D E C L A R A T I O N ______________________________________________*/
				
				extern  bit                 b_I2C_busy;
				extern  unsigned char       I2C_Err;
				extern  xdata               I2C_type_message  I2C_message;        // The I2C message to be sent in Master Mode
				extern  unsigned char xdata I2C_slave_data[I2C_NB_SLAVE_DATA];  //The slave data buffer when I2C ask in slave
				
				
				/*_____ M A C R O S ________________________________________________________*/
				
				
				#define I2C_RATIO_256     0x00
				#define I2C_RATIO_224     0x01
				#define I2C_RATIO_192     0x02
				#define I2C_RATIO_160     0x03
				#define I2C_RATIO_960     0x80
				#define I2C_RATIO_120     0x81
				#define I2C_RATIO_60      0x82
				#define I2C_RATIO_TIMER1  0x83
				
				#define I2C_CR2           0x80
				#define I2C_SSIE          0x40
				#define I2C_STA           0x20
				#define I2C_STO           0x10
				#define I2C_SI            0x08
				#define I2C_AA            0x04
				#define I2C_CR1           0x02
				#define I2C_CR0           0x01
				
				#define I2C_WAIT_EVENT    { while ( (SSCON & I2C_SI) != I2C_SI ); }
				#define I2C_SET_START     { SSCON |= I2C_STA;   } 
				#define I2C_CLEAR_START   { SSCON &= ~I2C_STA;  }
				#define I2C_SET_STOP      { SSCON |= I2C_STO;   }
				#define I2C_CLEAR_STOP    { SSCON &= ~I2C_STO;  }
				#define I2C_SET_AA        { SSCON |= I2C_AA;    } 
				#define I2C_CLEAR_AA      { SSCON &= ~I2C_AA;   }
				#define I2C_CLEAR_SI      { SSCON &= ~I2C_SI;   }
				
				
				
				#define Tranfer_OK      0
				#define BusError        1
				#define NoHostAdrAck    2
				#define NoHostDataAck   3
				#define ArbitrationLost 4
				#define UnknownError    5
				#define I2C_NOT_FREE    6
				
				
				#define I2C_READ        1
				#define I2C_WRITE       0
				
				/*_____ P R O T O T Y P E S ____________________________________________________________*/
				
				unsigned char I2C_baud_rate (unsigned int ratio);
				unsigned char I2C_Send_Message_polling( unsigned char slave_adr,bit rw, unsigned char nbytes, unsigned char *info );
				unsigned char I2C_Send_Message_interrupt( unsigned char slave_adr,bit rw, unsigned char nbytes, unsigned char *info);
				void I2C_decode_status();
				unsigned char I2C_slave_polling(void);
				void I2C_slave_interrupt(void);
				
				#endif /* _I2C_H_ */