i0模拟i2c.c

一款通过IO口模拟I2C中断的通信子程序！

#include	"config.h"

#define 	SDA		1<<14
#define	SCL		1<<11
uint8 		ack;
uint8 	data_buf[32];
uint8 	data_buf3[256];
uint8 	I2C_num;
uint8 	I2C_buf[32];
uint8 	I2C_buf1[32];
uint8 	I2C_buf2[32];
uint16	I2C_addr;


#define uchar unsigned char
uchar ACK_flag;


//==================================================================================================
void I2c_start(void)
{ 	
	IO0SET |= SDA;         
	IO0SET |= SCL;
	//Delay1(1);      						// 延时5us 
	IO0CLR |= SDA;
	//Delay1(1);
	IO0CLR |= SCL;
}
//==================================================================================================
void I2c_stop(void)
{ 
	IO0CLR |= SDA;   	  
	IO0SET |= SCL ;
	//Delay1(1);
	IO0SET |= SDA;
	//Delay1(1);
	IO0CLR |= SCL;
	//Delay1(2);
}





//==================================================================================================
void I2cSendByte(unsigned char dat)
{ 
	unsigned char n=8;     
	while(n--)
	{ 
		if((dat&0x80) == 0x80)    
		{
			IO0SET |= SDA;    
			IO0SET |= SCL;
			//Delay1(2);
			IO0CLR |= SCL;    
		}
		else
		{  
			IO0CLR |= SDA;    
			IO0SET |= SCL;
			//Delay1(2);
			IO0CLR |= SCL;  
		}
		dat = dat<<1;   
	}
}
//==================================================================================================
unsigned char I2creceiveByte(void)
{
	unsigned char n=8;    
	unsigned char tdata=0x01;
	IO0DIR &= (~(SDA));							//置P0.14为输入
	             			
	while(n--)
	{
		//Delay1(1);
		IO0SET |= SCL;
		//Delay1(1);	       
		tdata = tdata<<1;    
		if((IO0PIN & SDA) == SDA)
			tdata = tdata|0x01;   
		IO0CLR |= SCL;
	}
	IO0DIR |= SDA;
	return(tdata);
}
//-----------------------------------------------------------------------------------
uint8 I2C_GetAck(void) 
{ 
	IO0DIR &= (~(SDA));             			//置P0.14为输入
	//Delay1(1); 
	IO0SET |=SCL;
	//Delay1(1);
	
	if(IO0PIN & SDA)     //判断SDA
		ack = 1;
	else 
		ack = 0;
	
	IO0CLR |=SCL;
	IO0DIR |= SDA; 
	return ack; 
} 

//-----------------------------------------------------------------------------------
void I2c_PutAck(uint8 a)
{
  	IO0DIR  |= SDA;
  	if(a==0) IO0CLR |=SDA;    
    else 	 IO0SET |=SDA;
    
  	//Delay1(1);
   	IO0SET |=SCL;
 	//Delay1(1); 
 	IO0CLR |=SCL;            
	//Delay1(1);  
}
//==================================================================================================
uint8 Write_Nbyte(uint8 sla,  uint8 suba_type, uint32 CFG_add, uint8 *data, uint32 num)
{          
	uint8 sla1;
	sla1=sla;
	I2c_start();                
	I2cSendByte(sla1);     
	ACK_flag =I2C_GetAck();
	if (ACK_flag )
	{
		I2c_stop();
		return 0;
	}
	
	if(suba_type==2) 
	{	
		I2cSendByte(CFG_add>>8);
		ACK_flag = I2C_GetAck();
		if (ACK_flag)
		{
			I2c_stop();
			return 0;
		}
	}
			  
	I2cSendByte(CFG_add);       
   	ACK_flag = I2C_GetAck();
    	if ( ACK_flag  )
	{
		I2c_stop();
		return 0;
		}
	
	while(num--)
	{
    	
    	I2cSendByte(*data);       
    	data++;
    	ACK_flag = I2C_GetAck();
    	if ( ACK_flag )
		{
			I2c_stop();
			return 0;
		}
   	}	
	I2c_stop();         
	return(1);
}

//==================================================================================================
uint8 Read_Nbyte(uint8 sla, uint8 p0, uint8 suba_type, uint32 CFG_add, uint8 * buff, uint32 num)
{ 
	uint8 sla1;
	if(num >0)
	{
		sla1=sla;
	
		if(p0==1)
			sla1=sla1+2;
	
		I2c_start();
    	I2cSendByte(sla1);
    	 ACK_flag = I2C_GetAck();  
   	 	if ( ACK_flag)
		{
			I2c_stop();
			return 0;
		}
	
		if(suba_type==2) 
		{
			I2cSendByte((CFG_add>>8)); 
			 ACK_flag = I2C_GetAck();
			 if (  ACK_flag)
			{
				I2c_stop();
				return 0;
			}
		}
		
		I2cSendByte(CFG_add);
    	ACK_flag = I2C_GetAck();
    	if ( ACK_flag )
		{
			I2c_stop();
			return 0;
		}
	
	    I2c_start();
    	I2cSendByte(sla1+1);
    	ACK_flag =I2C_GetAck();  
	    if (ACK_flag )
		{
			I2c_stop();
			return 0;
		}
	
		num= num-1;                        
		while(num--)
		{ 
			*buff=I2creceiveByte();
			buff++;
			I2c_PutAck(0);
		}
		*buff=I2creceiveByte();
   		 I2c_PutAck(1);                 
		I2c_stop();
		return(1);
	}
	else
		return 0;
}