i2c.c

来自「LED控制」· C语言 代码 · 共 259 行

#include	<pic.h>
#include	"..\inc\include.h"
#include	"..\lib\I2C.h"

#define	LED			RB0
#define	LED1		RB0
#define	LED2		RB1
#define	LED3		RB2

#define	SCL			RC3
#define	SDA			RC4


void I2C_Init(void)
{
	TRISC3 =0;	//SCL output
	TRISC4 =0;	//SDA output
	
	SCL = 1;
	SDA = 1;
	
	SSPCON &= ~(0x0F);	
	SSPCON |= 0x08;	//I2C Master mode, clock = FOSC/(4 * (SSPADD + 1))
	/*
	SSPM3 =1;	//master mode
	SSPM2 =0;
	SSPM1 =0;
	SSPM0 =0;*/
	SMP = 1;		//100KHz
	CKE = 0;		//not smbus
	SSPADD = 0x13;	//100KHz 
	SSPEN = 1;	//enable I2C
	
}

// ========= read 1 byte data from 24LC256 (15 bit word address) ==============
unsigned char EEPROM_ReadByte(unsigned int Addr, unsigned char *DataBuf)
{
   	unsigned char cnt=0;

	while((SSPCON2 & 0x1F) || RW ){		//if not in idle mode, reinitial the serial bus
		SSPEN = 0;
		NOP();
		SCL = 1;
		SDA = 1;
		NOP();
		SSPEN = 1;						
	}	

	SEN = 1;            				//send the start condition
  	while(SEN);     
  	SSPIF = 0;
  	SSPBUF = 0b10100000;				//send control byte
  	while(!SSPIF); 
	
	while(ACKSTAT){ 					//if return no ACK, resend the start bit and control byte
		RSEN = 1;           			//send the restart condition
		while(RSEN);
	  	SSPIF = 0;
	  	SSPBUF = 0b10100000;			//send control byte
	  	while(!SSPIF); 
		if(cnt++>200) return NACK;		//repeat 200 times
	}
  	
    if(ACKSTAT) return NACK;  
	SSPIF = 0;
	SSPBUF = (unsigned char)(Addr>>8);	//send high address
	while(!SSPIF);
    
    if(ACKSTAT) return NACK;  
	SSPIF = 0;
	SSPBUF = (unsigned char)Addr;		//send low address
	while(!SSPIF);
    
    if(ACKSTAT) return NACK;  
	RSEN = 1;           				//send the restart condition
	while(RSEN);
	
    if(ACKSTAT) return NACK;  
	SSPIF = 0;
	SSPBUF = 0b10100001;				//send control byte
	while(!SSPIF);
    
    if(ACKSTAT) return NACK;  
	SSPIF = 0;
	RCEN = 1;       					//enable master for 1 byte reception???
	//while(RCEN);	//Automatically cleared by hardware 
	while(!SSPIF);
	//if(!RCEN) LED1 = 1;
    
	ACKDT = 1;
	ACKEN = 1;          				//send NACK
	while (ACKEN ==1); 
	
	PEN = 1;            				//send the stop condition
	while(PEN);

  	*DataBuf = SSPBUF;					//return byte data wanted to read
  	return NOERR;
}

// ========= write 1 byte data to 24LC256 (15 bit word address) ===============
unsigned char EEPROM_WriteByte(unsigned int Addr, unsigned char cData)
{
  	unsigned char cnt=0;
  	while((SSPCON2 & 0x1F) || RW ){		//if not in idle mode, reinitial the serial bus
		SSPEN = 0;
		NOP();
		SCL = 1;
		SDA = 1;
		NOP();
		SSPEN = 1;						
	}	
	
	SEN = 1;            				//send the start condition
  	while(SEN);     
  	SSPIF = 0;
  	SSPBUF = 0b10100000;				//send control byte
  	while(!SSPIF); 
	
	while(ACKSTAT){ 					//if return no ACK, resend the start bit and control byte
		RSEN = 1;           			//send the restart condition
		while(RSEN);
	  	SSPIF = 0;
	  	SSPBUF = 0b10100000;			//send control byte
	  	while(!SSPIF); 
		if(cnt++>200) return NACK;		//repeat 200 times
	}
    
    if(ACKSTAT) return NACK;  
	SSPIF = 0;
	SSPBUF = (unsigned char)(Addr>>8);	//send high address
	while(!SSPIF);
    
    if(ACKSTAT) return NACK;  
	SSPIF = 0;
	SSPBUF = (unsigned char)Addr;		//send low address
	while(!SSPIF);
    
    if(ACKSTAT) return NACK;  	
	SSPIF = 0;
	SSPBUF = cData;						//send data that want to be write
	while(!SSPIF);
		
	PEN = 1;							//send the stop condition
	while(PEN); 
	
  	return NOERR;  	
}

// ========= read 1 byte data from 24LC01/02 (7/8 bit word address) ==============
unsigned char EEPROM_ReadByte1(unsigned char Addr, unsigned char *DataBuf)
{
   	unsigned char cnt=0;

	while((SSPCON2 & 0x1F) || RW ){		//if not in idle mode, reinitial the serial bus
		SSPEN = 0;
		NOP();
		SCL = 1;
		SDA = 1;
		NOP();
		SSPEN = 1;						
	}	

	SEN = 1;            				//send the start condition
  	while(SEN);     
  	SSPIF = 0;
  	SSPBUF = 0b10100000;				//send control byte, write
  	while(!SSPIF); 
	
	while(ACKSTAT){ 					//if return no ACK, resend the start bit and control byte
		RSEN = 1;           			//send the restart condition
		while(RSEN);
	  	SSPIF = 0;
	  	SSPBUF = 0b10100000;			//send control byte
	  	while(!SSPIF); 
	  	NOP();
	  	NOP();
	  	NOP();
		if(cnt++>200) return NACK;		//repeat 200 times
	}
  	
    if(ACKSTAT) return NACK;  
	SSPIF = 0;
	SSPBUF = Addr;						//send word address
	while(!SSPIF);
    
    if(ACKSTAT) return NACK;  
	RSEN = 1;           				//send the restart condition
	while(RSEN);
	
    if(ACKSTAT) return NACK;  
	SSPIF = 0;
	SSPBUF = 0b10100001;				//send control byte, read
	while(!SSPIF);
    
    if(ACKSTAT) return NACK;  
	SSPIF = 0;
	RCEN = 1;       					//enable master for 1 byte reception???
	//while(RCEN);	//Automatically cleared by hardware 
	while(!SSPIF);
	//if(!RCEN) LED1 = 1;
    
	ACKDT = 1;
	ACKEN = 1;          				//send NACK
	while (ACKEN ==1); 
	
	PEN = 1;            				//send the stop condition
	while(PEN);

  	*DataBuf = SSPBUF;					//return byte data wanted to read
  	return NOERR;
}

// ========= write 1 byte data to 24LC01/02 (7/8 bit word address) ===============
unsigned char EEPROM_WriteByte1(unsigned char Addr, unsigned char cData)
{
  	unsigned char cnt=0;
  	while((SSPCON2 & 0x1F) || RW ){		//if not in idle mode, reinitial the serial bus
		SSPEN = 0;
		NOP();
		SCL = 1;
		SDA = 1;
		NOP();
		SSPEN = 1;						
	}	
	
	SEN = 1;            				//send the start condition
  	while(SEN);     
  	SSPIF = 0;
  	SSPBUF = 0b10100000;				//send control byte
  	while(!SSPIF); 
	
	while(ACKSTAT){ 					//if return no ACK, resend the start bit and control byte
		RSEN = 1;           			//send the restart condition
		while(RSEN);
	  	SSPIF = 0;
	  	SSPBUF = 0b10100000;			//send control byte
	  	while(!SSPIF); 
		if(cnt++>200) return NACK;		//repeat 200 times
	}
    
    if(ACKSTAT) return NACK;  
	SSPIF = 0;
	SSPBUF = Addr;						//send word address
	while(!SSPIF);
    
    if(ACKSTAT) return NACK;  	
	SSPIF = 0;
	SSPBUF = cData;						//send data that want to be write
	while(!SSPIF);
		
	PEN = 1;							//send the stop condition
	while(PEN); 
	
  	return NOERR;  	
}